WO2019073084A1 - A gene for fungal disease resistance in plants - Google Patents

Abstract

The invention provides a gene capable of providing resistance or improving resistance and a recombinant construct comprising said gene. The invention also relates to plant cells transformed with the gene and plant material, including plant cell cultures, seeds and plants, comprising the transformed plant cells.

Description

Title

A gene for fungal disease resistance in plants. Field of the invention

The current invention relates to resistance to Fusarium head blight disease in plants. In particular, the invention relates to a gene capable of providing resistance or enhancing resistance and a recombinant construct including said gene. The invention also relates to plant cells transformed with the gene and plant material, including plant cell cultures, seeds and plants, comprising the transformed plant cells.

Background to the invention Fusarium head blight (FHB) is a fungal disease in plants, in particular, in cereals such as wheat, barley and oats. It is caused by a Fusarium fungus. The species Fusarium grammearum is the predominant causal agent of the disease in most areas of the world. The Fusarium graminearum pathogen is hemibiotrophic, with a short biotrophic phase preceding a necrotrophic phase (where the pathogen feeds off dead plant tissue). In wheat, the fungus infects the head of the plant, mostly by entering through the flowers, and causes the kernels to shrivel up. It can also produce a mycotoxin called deoxynivalenol (DON) that further reduces the quality of kernel. The phytotoxic toxin DON is a type B trichothecene and is an inhibitor of protein synthesis. The fungus also produces the mycotoxin zearalenone, an estrogenic mycotoxin. These toxins can also be harmful to both animals and humans.

FHB in wheat is an economic presage and its post-harvest grain loss and considerable health risk to both animals and humans, due to accumulation of mycotoxin deoxynivalenol (DON), are well known. Given the economic concern of FHB, several control strategies have been developed to avert FHB epidemics. These include resistance cultivars and systems for the control of FHB and both chemical and biological control.

The use of host resistance is considered to be an efficacious means to control FHB and trichothecene mycotoxin accumulation in wheat and several approaches have been described previously. Breeding and selection of crossed lines for durable resistance to disease and yield stability take time and lines behave differently in different environments. There is also the chance of resistance breakdown in lines developed with this approach. NAC transcription factors are a family of transcriptional regulators in plants. Wheat NAC transcription factors are known to have negative effects of disease resistance in wheat, and in particular have been shown to play a negative role regulating the defence against stripe rust disease (Xia N, Zhang G, Liu X-Y, Deng L, Cai G-L, Zhang Y, Wang X-J, Zhao J, Huang L-L, Kang Z-S. 2010. Characterization of a novel wheat NAC transcription factor gene involved in defense response against stripe rust pathogen infection and abiotic stresses. Molecular biology reports 37(8): 3703-3712; · Wang F, Lin R, Feng J, Chen W, Qiu D, Xu S. 2015. TaNACI acts as a negative regulator of stripe rust resistance in wheat, enhances susceptibility to Pseudomonas syringae, and promotes lateral root development in transgenic Arabidopsis thaliana. Frontiers in Plant Science 6: 108; · Feng H, Duan X, Zhang Q, Li X, Wang B, Huang L, Wang X, Kang Z. 2014. The target gene of tae-miR164, a novel NAC transcription factor from the NAM subfamily, negatively regulates resistance of wheat to stripe rust. Molecular Plant Pathology 15(3): 284-296; · Bing W, Jinping W, Na S, Ning W, Jing Z, Zhensheng K. 2018. A novel wheat NAC transcription factor, TaNAC30, negatively regulates resistance of wheat to stripe rust. Journal of integrative plant biology 60(5): 432-443.)

It is an object of the current invention to provide a gene which provides FHB resistance and DON resistance in plants. Statements of Invention

The Applicant has discovered a wheat NAC transcription factor that is capable of enhancing or providing resistance to FHB in plants. The NAC transcription factor is located on chromosome 5D of Triticum aestivum, and the nucleic acid sequence of the gene isolated from Triticum aestivum cultivar CM82036 is provided in SEQUENCE ID NO: 1 (hereafter TaNAC5D-cm). The same gene has been identified in Triticum aestivum, cultivar Chinese spring (TaNAC5D-cs). The Applicant has isolated the gene, cloned the gene into an expression vector, and generated transgenic wheat and Arabidopsis plants overexpressing the gene. The data provided herein demonstrates that TaNAC5D surprisingly enhances plant resistance to the mycotoxin DON, and enhances wheat resistance to F. graminearum. The Applicant has also shown that TaNAC5D shares 100, 95 and 94% homology with sequences on chromosomes 5D, 5A and 5B, respectively, of the published wheat cv. Chinese Spring genome (Fig. 1 ), that TaNAC5D homologs were found within and restricted to the Pooideae subfamily of grasses (Fig. 2A and B), and that homologs of TaNAC5D (TaNAC5A and TaNAC5B) share the same temporal expression profile in response to FHB in different wheat genotypes (and therefore share the same function regarding promoting FHB resistance). The invention therefore relates to the isolated TaNAC5D gene and protein, homologs and homeologs of the gene capable of enhancing or providing resistance to FHB in plants (especially from the Triticum and Aestivum family), nucleic acid constructs comprising these genes, and transgenic plants engineered to overexpress the gene. A first aspect of the invention provides a recombinant construct comprising a nucleotide sequence of SEQUENCE ID NO. 1 or a functional variant or functional fragment thereof.

Preferably, the functional variant has at least 30% sequence identity with SEQUENCE ID N0.1 .

Preferably, the functional variant has at least 70% sequence identity with SEQUENCE ID N0.1 .

Preferably, the functional variant has at least 90% sequence identity with SEQUENCE ID N0.1 .

Preferably, the functional variant has at least 94% sequence identity with SEQUENCE ID NO. 1 .

In one embodiment, the functional variant is a homeolog or homolog of SEQUENCE ID NO: 1 . In one embodiment, the homolog or homeolog has at least 93% sequence identity with SEQUENCE ID NO; 1 . In one embodiment, the homolog or homeolog has at least 94% sequence identity with SEQUENCE ID NO; 1 . In one embodiment, the homolog is derived from a wheat plant (for example Spelta, Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, and soft White).

Examples of homeologs of TaNAC5D-cm include TaNAC5D-cs (100% identical to SEQUENCE ID NO: 1 ), TaNAC5A-cs (SEQUENCE ID NO: 3), and TaNAC5B-cs (SEQUENCE ID NO: 4).

Examples of homologs of TaNAC5D-cm include TuNAC (SEQUENCE ID NO: 8), TtNAC (SEQUENCE ID NO: 9), TmNACI (SEQUENCE ID NO: 10), TmNAC2 (SEQUENCE ID NO: 1 1 ), and AtNAC (SEQUENCE ID NO: 7). A recombinant host cell comprising a construct of the invention and as described herein is also provided by a further aspect of the invention. A further aspect of the invention provides a transformation platform comprising a recombinant construct of the invention.

Typically, the transformation platform comprises bacteria capable of mediating cellular transformation or biolistic transformation.

The invention also provides an isolated nucleotide sequence comprising or consisting of SEQUENCE ID NO. 1 or a functional variant or a functional fragment thereof. The functional variants and fragments are as described herein.

The invention also provides an amino acid sequence comprising or consisting of SEQUENCE ID NO. 2 or a functional variant or functional fragment thereof. The functional variants and fragments are as described herein. The invention also provides a protein, peptide or polypeptide encoded by an amino acid sequence of SEQUENCE ID NO. 2 or a functional variant or functional fragment thereof. The isolated nucleotide or peptide is for providing FHB resistance or enhancing FHB resistance in plant material. The invention also provides plant material genetically transformed or modified with a nucleotide sequence, recombinant construct or transformation platform of the invention.

Typically, the plant material comprises a plant cell carrying a transgene, in which the transgene comprises (or consists of) a nucleotide sequence of SEQUENCE ID NO. 1 or a functional variant or a functional fragment thereof.

The invention also provides a method of genetically transforming a plant material comprising the steps of transforming a cell or cells of the plant material with a nucleotide sequence, recombinant construct or transformation platform of the invention.

Preferably, the transformed cell (or cells) is capable of expression of the nucleotide sequence of SEQUENCE ID NO. 1 or a functional variant or functional fragment thereof.

The invention also provides a method of producing a transgenic plant or plant material comprising the steps of genetically transforming a plant or plant material according to a method of the invention. The invention also provides a method of producing a transgenic cell which comprises the steps of genetically transforming a cell or cells according to the method of the invention. Typically, the step of genetically transforming comprises inoculating cells with a transformation platform comprising a recombinant construct of the invention, culturing the cells under conditions that enable the transformation platform to transform the cells, selectively screening the inoculated cells for transformed cells, and isolating the or each transformed cell. Typically, the step of screening comprises detecting the presence of a selectable marker and/or the nucleotide or peptide of the invention. Preferably, the transgenic plant or plant material is thus resistant to FHB or has enhanced resistance to FHB compared to non-modified or non-transgenic plants or plant material.

Preferably, the transgenic plant or plant material is thus resistant to DON or has enhanced resistance to DON compared to non-modified or non-transgenic plants or plant material.

Typically, the plant material is selected from the group comprising a plant, a plant cell, plant cell culture, plant tissue and seed for a plant.

Preferably, the plant is a cereal. Typically, said cereal is selected from the group comprising maize, rice, wheat, barley, sorghum, millet, oats, soybean and rye. Preferably, the cereal is wheat.

A further aspect of the invention provides an isolated peptide comprising (or consisting of) SEQUENCE ID NO. 2 or a functional variant thereof or a functional fragment thereof.

A further aspect of the invention provides a method for providing FHB resistance or enhancing FHB resistance in a plant material.

A further aspect of the invention provides a method for increasing tolerance to development of FHB symptoms in a plant material.

Use of the construct, nucleotide or transformation platform of the current invention and as described herein to provide resistance or to enhance resistance to FHB and/or DON in a plant material is also provided.

Other aspects and preferred embodiments of the invention are defined and described in the other claims set out below. Definitions

Where used herein and unless specifically indicated otherwise, the following terms are intended to have the following meanings in addition to any broader (or narrower) meanings the terms might enjoy in the art:

Unless otherwise required by context, the use herein of the singular is to be read to include the plural and vice versa. The term "a" or "an" used in relation to an entity is to be read to refer to one or more of that entity. As such, the terms "a" (or "an"), "one or more," and "at least one" are used interchangeably herein.

In the specification, the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

"TaNAC5D" when used here in means a gene that is capable of enhancing or providing resistance to FHB in plants. It is novel NAC transcription factor characterised as a nuclear protein that is able to stimulate transcription in yeast. It has a nucleotide sequence of SEQUENCE ID NO. 1 and an amino acid sequence of SEQUENCE ID NO. 2. TaNAC5D has homologs with greater than 93% nucleotide sequence identity in Aegilops tauschii, Triticum monococum, Triticum turgidum, Triticum urartu and Triticum aestivum. "FHB resistance" as defined herein is the reduction or absence of FHB on or in the plant, when exposed to FHB causing pathogens. The reduction is relative to FHB on or in the wild-type plant, i.e. one that does not overexpress TaNAC5D, when exposed to FHB causing pathogens. FHB resistance may be measured by a decrease, or an absence, of FHB symptoms in plants. Such methods are known in the art.

The phrase "FHB symptoms" when used herein refers to an effect of infection with FHB and includes, but is not limited to, one or more of damage of spikelets, premature discolouration and/or bleaching of spikelets, deoxynivalenol mycotoxin contamination of grain, and shrivelling and/or wrinkling of kernels. Methods of analysing the phenotypic effects are known in the art.

The term "functional variant" when used herein is taken to mean a variant of SEQUENCE ID NO. 1 or SEQUENCE ID NO. 2, which is capable of providing resistance or enhancing resistance to FHB in plants and which typically include the NAM domain. In one embodiment, the functional variant is or comprises a homeolog or homolog of SEQUENCE ID NO: 1 . In one embodiment, the functional variant has at least 93% sequence identity with SEQUENCE ID NO; 1. In one embodiment, the functional has at least 94% sequence identity with SEQUENCE ID NO; 1. In one embodiment, the homolog is derived from a wheat plant (for example Spelta, Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, and soft White) or a grass plant (for example Aegilops taushii). Examples of homeologs of TaNAC5D-cm include TaNAC5D-cs (100% identical to SEQUENCE ID NO: 1 ), TaNAC5A-cs (SEQUENCE ID NO: 3), and TaNAC5B-cs (SEQUENCE ID NO: 4). Examples of homologs of TaNAC5D-cm include TuNAC (SEQUENCE ID NO: 8), TtNAC (SEQUENCE ID NO: 9), TmNACI (SEQUENCE ID NO: 10), TmNAC2 (SEQUENCE ID NO: 1 1 ), and AtNAC (SEQUENCE ID NO: 7). The term "functional variant thereof" should be also be understood to include sequences which are substantially identical to SEQUENCE ID NO: 1 , but which encodes a protein that is altered in respect of one, two, three, four, five, or more, amino acid residues compared to SEQUENCE ID NO: 2, in such a way so as not to significantly alter the function of providing resistance or enhancing resistance to FHB in plants. Typically, the variant is a (nucleotide or amino acid) sequence having from about 30% to about 99% sequence identity with a given sequence. Generally, the variant is a (nucleotide or amino acid) sequence having from about 70% to about 99% sequence identity, preferably 70, 75, 80, 85, 86, 88, 87, 89,90, 91 , 92, 93, 94, 95, 96, 97, 98 or 99%, sequence identity with a given sequence and which is typically capable of enhancing or providing resistance to FHB in plants, i.e. variant is a functional variant. Such alterations include, insertion, addition, deletion and/or substitution of an amino acid residue(s), or a nucleotide residue(s). It will be appreciated that such variants may be naturally occurring variants or may be a non-natural variant. The term variant also includes a fragment of a sequence. In relation to a variant of a peptide, the insertion, addition and substitution with natural and modified amino acids are envisaged. The variant may have conservative amino acid changes, wherein the amino acid being introduced is similar structurally, chemically, or functionally to that being substituted.

The term "fragment" means a segment of a given sequence. Typically, the fragment has from about 10 to 1000 contiguous amino acids, preferably about 50, 100, 200, 300, 400, 500, 600, 700, 800, or 900 amino acids. Typically, the fragment has from 10 to 3000 contiguous nucleotides preferably about 100, 250, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, 2500 35 or 2750 nucleotides. The fragment is a functional fragment, i.e., it is a segment of SEQUENCE ID NO. 1 or SEQUENCE ID NO. 2 which is capable of providing resistance or enhancing resistance to FHB in plants. In In terms of "sequence homology", the term should be understood to mean that a variant (or homolog) which shares a defined percent similarity or identity with a reference sequence when the percentage of aligned residues of the variant (or homolog) are either identical to, or conservative substitutions of, the corresponding residues in the reference sequence and where the variant (or homolog) shares the same function as the reference sequence.

In this specification, "homology", "identity" or "similarity" refers to the relationship between two peptides or two nucleotide sequences based on an alignment of the sequences. The term "identity" when used herein means the percentage of identical, or conservative substitutions of, amino acid or nucleotide residues at corresponding positions in two sequences when the sequences are aligned and is across the entire length of the sequence, i.e. a variant (or homolog) that shares 70% sequence identity with a reference sequence is one in which any 70% of aligned residues of the variant (or homolog) are identical to, or conservative substitutions of, the corresponding residues in the reference sequence across the entire length of the sequence. For sequence comparison, one sequence acts as a reference sequence, to which test sequences are compared.

This alignment and the percent homology, similarity or sequence identity can be determined using software programs known in the art, for example, BLAST, EMBOSS Needle or Clustal Omega, using default parameters. Details of these programs can be found at the following Internet address:http://www.ncbi. nlm.nih.gov.

As used herein, the term "genetically modified" as applied to a cell, including a microorganism, means genetically engineered using recombinant DNA technology, and generally involves the step of synthesis of a suitable expression vector (see below) and then transfecting (i.e. stably or transiently) the expression vector into a host cell (generally stable transfection).

As used herein, the term "recombinant cell", "transformed cell", "recombinant plant" or "transformed plant" refers to a cell or plant comprising an exogenous nucleic acid stably integrated into the cellular genome that comprises a nucleotide sequence coding for TaNAC5D. In another embodiment, it may be a cell comprising a non-integrated (i.e., episomal) exogenous nucleic acid, such as a plasmid, cosmid, phagemid, or linear expression element, which comprises a sequence coding suitable for expression of a gene. In other embodiments, the present invention provides a cell line produced by stably transfecting a host cell, such as a plant host cell, with a plasmid comprising an expression construct of the invention. In one embodiment, the cell is engineered for heterologous expression of a gene. The term "encode" as it is applied to nucleotide sequences refers to a nucleotide which is said to "encode" a polypeptide or peptide if, in its native state or when manipulated by methods well known to those skilled in the art, it can be transcribed and/or translated to produce the mRNA for the polypeptide and/or a fragment thereof.

The terms "polypeptide" and "protein" are used interchangeably herein to refer to a polymer of amino acid residues. The terms also apply to amino acid polymers in which one or more amino acid residues is a modified residue, or a non-naturally occurring residue, such as an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers.

The term "peptide" refers to a chain of amino acids. The peptide may or may not be "isolated", that is to say removed from the components which exist around it when naturally occurring. The terms also apply to amino acid polymers in which one or more amino acid residues is a modified residue, or a non-naturally occurring residue, such as an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers. The term "amino acid" as used herein refers to naturally occurring and synthetic amino acids, as well as amino acid analogues and amino acid mimetics that have a function that is similar to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those modified after translation in cells (e.g. hydroxyproline, gammacarboxyglutamate, and O-phosphoserine). The phrase "amino acid analogue" refers to compounds that have the same basic chemical structure (an alpha carbon bound to a hydrogen, a carboxy group, an amino group, and an R group) as a naturally occurring amino acid but have a modified R group or modified backbones (e.g. homoserine, norleucine, methionine sulfoxide, methionine methyl sulphonium). The phrase "amino acid mimetic" refers to chemical compounds that have different structures from, but similar functions to, naturally occurring amino acids. It is to be appreciated that, owing to the degeneracy of the genetic code, nucleic acid molecules encoding a particular polypeptide may have a range of polynucleotide sequences. For example, the codons GCA, GCC, GCG and GCT all encode the amino acid alanine. The term "nucleic acid molecule" when used herein to include unmodified DNA or RNA or modified DNA or RNA. For example, the nucleic acid molecules or polynucleotides of the disclosure can be composed of single- and double stranded DNA, DNA that is a mixture of single- and double-stranded regions, single- and double-stranded RNA, and RNA that is a mixture of single- and double-stranded regions, hybrid molecules comprising DNA and RNA that may be single-stranded or, more typically double-stranded or a mixture of single- and double-stranded regions. In addition, the nucleic acid molecules can be composed of triple stranded regions comprising RNA or DNA or both RNA and DNA. The nucleic acid molecules of the disclosure may also contain one or more modified bases or DNA or RNA backbones modified for stability orfor other reasons. "Modified" bases include, for example, tritiated bases and unusual bases such as inosine. A variety of modifications can be made to DNA and RNA; thus "nucleic acid molecule" embraces chemically, enzymatically, or metabolically modified forms. The term "polynucleotide" shall have a corresponding meaning.

In this specification, the term "plant material" should be understood to mean any constituent of a plant comprising plant cells, including a plant cell, plant cell culture, plant tissue, plant, or seed from a plant.

The term "cell" should be understood to mean a cell from a plant. In a particularly preferred embodiment, the cell is a plant cell selected from the group consisting of: maize, rice, wheat, barley, sorghum, millet, oats, soybean and rye. Typically, the cell is obtained from a monocotyledon or dicotyledon plant. In a particularly preferred embodiment, the cell is a plant cell selected from the group consisting of: Arabidopsis; potato (i.e. Solanum tuberosum); tobacco (Nicotiana tabaccum); wheat; barley; maize and rice; Glycine max; Brassica napus.

The term "transgenic cell" should be understood to mean a cell that comprises a transgene incorporated, ideally stably incorporated, into its genome.

In this specification, the term "plant" should be understood to mean a monocotyledon or dicotyledon plant. Preferably, the plant is a monocotyledon plant. In a particularly preferred embodiment, the plant is a cereal plant, typically a small; grain cereal plant, preferably selected from the group consisting of: wheat; barley; maize and rice; Arabidopsis; potato (i.e. Solanum tuberosum); tobacco (Nicotiana tabaccum); Glycine max; Brassica napus.

The term "transformation platform" should be understood to mean the genetic machinery required to transfer the transgene into a cell, and generally comprises an organism, for example a bacteria, capable of mediating cellular transformation and containing a recombinant construct of the invention. Examples of transformation platforms include E.coli, A. tumefaciens, E. adhaerens, and certain "transbacter" strains of bacteria. Other examples include: biolistic transformation and floral dipping. The term "transgene" should be understood to mean the nucleotide of the invention, and functional variants or functional fragments thereof. The term "recombinant construct" should understood to mean a polynucleotide construct designed to transfer exogenous genetic material into a target cell, often refered to as vectors. In general, the construct comprises a promoter region that is functional in a plant cell operably linked to a polynucleotide of the invention. The construct can comprise a number of sequence elements, including more than one coding sequence, promotors, and selectable markers. Typically, the construct or vector comprises a Ti plasmid (or a fragment thereof), suitably containing a region of T-DNA and ideally at least one or more virulence genes. Preferably, the Ti plasmid or fragment thereof is obtained from Agrobacterium. Suitably, the transgene is incorporated into the T-DNA region of the Ti plasmid. More preferably, the transgene is incorporated between the left and right borders of the T-DNA region. The Ti plasmid may comprise a selectable marker gene, although this is not required as successful transformation with the transgene may be rapidly detected for example by means of high-throughput PCR. When employed, the selectable marker gene is suitably contained within the T-DNA region and ideally operatively linked to the transgene. The term "promoter region functional in a plant cell" refers to a polynucleotide sequence that is capable of driving expression of an operably linked transgene in a plant transformed with a recombinant construct comprising the promotor operably linked to the transgene. Generally, the promoter is capable of driving overexpression of the transgene. Examples of promoters include the rice actin promotor, maize ubiquitin promotor and the 35S Cauliflower Mosaic Virus promotor.

The term "operatively linked" should be understood to mean that in transformed cells the promoter will be transferred with the transgene and the transgene will be under the control of the promoter.

In this specification, the term "selectable marker" is taken to mean an exogenous piece of genetic material that when incorporated into the host DNA will confer a detectable signal of effective transformation. In a preferred embodiment, the selectable marker gene is selected from a group comprising: hph, neomycin phosphotransferase II [NPT ll/Neo]), aadA and tetR. Appropriate reporter transgenes could include GUS or GFP.

The term "overexpression" refers to expression of a gene or protein in an increased quantity relative to the wild-type. In one embodiment, the expression may be enhanced by transfection of an expression vector containing the necessary machinery to express TaNAC5D into a host cell. The expression may be enhanced by a promoter to produce multiple copies of mRNA and large quantities of the selected product TaNAC5D. The host cell may already express endogenous TaNAC5D.

The phrase "nucleotide of the invention" when used herein refers to SEQUENCE ID NO. 1 or a functional variant thereof or a functional fragment thereof.

The phrases "amino acid sequence of the invention" or "peptide of the invention" when used herein refer to SEQUENCE ID NO. 2 or a functional variant thereof or a functional fragment thereof.

Brief Description of the Figures The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates Multiple alignments of TaNA C5D wheat homeologs. The coding sequence from wheat variant TaNAC5D-cm (cultivar CM82036) (SEQUENCE ID NO:1 ) was isolated from a cDNA bank and used to retrieve the different variants from the analyses of the reference wheat genome (cultivar Chinese spring). Resulting sequences TaNAC5A-cs (SEQUENCE ID 3), TaNAC5B-cs (SEQUENCE ID 4) and TaNAC5D-cs (identical to SEQUENCE ID 1 ) were aligned and compared with those coming from the CM82036 cultivar using MULTALIN. Figure 2 illustrates Multiple alignments of the different TaNAC5D homeologs and homologs. Alignments of the coding sequences (A) or corresponding protein sequences (B) of TaNAC5D homeologs and homologs. Sequences were identified by BLASTn query of the nucleotide sequences in the NCBI GenBank and genome databases of: wheat (Wheat URGI and Cereals DB), Triticum monococum, Triticum urartu and Triticum turgidum (Dubcovskylab). Abbreviations: Aegilops tauschii (At), Triticum monococum (Tm), Triticum turgidum (Tt), Triticum urartu (Tu) and Triticum aestivum (Ta).

Figure 3 is a graph illustrating the effect of TaNAC5D overexpression on Arabidopsis DON Resistance. TaNAC5D overexpressor lines (OE-1 , OE-2 and OE-3) and control plants (WT) were tested for their growth response in the absence or presence of 33.8 μΜ DON. After 14 days of growth seedlings fresh weight was measured. Error bars indicate ± SEM. Asterisks show significant differences compared to the WT in the same condition (Mann-Whitney L/ test; ^*, P<0.05; ^***, PO.001 ).

Figure 4 is a graph illustrating the transcript level of TaNAC5D in overexpressor lines (OE-1 and OE-2) and control plants (WT) grown under normal plant growth conditions determined by qRT-PCR. The threshold cycle (Ct) values obtained by qRT-PCR were used to calculate the relative gene expression using the formula 2^{"(Cttarget 9ene " ct housekeepin9 gene)} Error bars indicate ± SEM (n = 6).

Figure 5 is a graph illustrating the effect of TaNAC5D overexpression on the susceptibility of wheat to FHB disease. At mid-anthesis, flowering spikelets from overexpressor lines (OE-1 and OE-2) or control plants (WT) were spray-inoculated with F. graminearum. Disease was assessed at different days post inoculation and data presented correspond to the percentage of infected spikelets per head at 21 days (A) or to the area under the disease progress curve (AUDPC; B). Error bars indicate ± SEM (n = 20). Asterisks show significant differences compared to the WT (Mann-Whitney U test; ^*, P<0.05; ^**, P<0.01 ; ^***, P<0.001 ).

Detailed Description of the Invention All publications, patents, patent applications and other references mentioned herein are hereby incorporated by reference in their entireties for all purposes as if each individual publication, patent or patent application were specifically and individually indicated to be incorporated by reference and the content thereof recited in full.

In its broadest sense, the current invention provides a gene, TaNAC5D, and variants thereof such as homologs and homeologs for resistance to Fusarium head blight (FHB) in plants. In particular, the current invention provides a gene, TaNAC5D, and variants thereof for resistance to FHB in plants caused by Fusarium graminearum. It will be understood that the FHB can be caused by any Fusarium species. Examples include but are not limited to, F. avenaceum, F. bubigeum, F. culmorum, F. graminearum, F. langsethiae, F. oxysporum, F. poae, F. solani, F. sporotrichioides, F. tricinctum, F. verticillioides, F. virguliforme.

The current inventors have surprisingly found that TaNAC5D, a novel transcription factor, provides resistance to FHB in plants. The inventors have found that plant material that overexpresses TaNAC5D has resistance or an improved level of resistance to FHB when compared to a plant material that does not overexpress TaNAC5D. The wild-type plant may express endogenous TaNAC5D. The gene, TaNAC5D, also provides or enhances resistance to the mycotoxin deoxynivalenol (DON) in plants, e.g. Arabidopsis. Resistance to DON provides or enhances resistance to FHB disease.

TaNAC5D is a transcription factor from the Triticeae tribe of Pooideae subfamily of grasses. TaNAC5D has homologs with greater than 93% nucleotide sequence identity in Aegilops tauschii, Triticum monococum, Triticum turgidum, Triticum Urartu and Tritiscum aestivum^ The nucleotide sequences of the homologs are as follows:

>AtNAC (Aegilops taushii) SEQU ENCE I D NO. 7

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCGGCGTTCAAGTTCGACCCCACCGACGC CGGCATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTCGACGAGCCCCACGGCCGCGAGCACG CCGTGATCGACGACGACCCCATGAGCATCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACC AGCGACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCGCGTCACGCGCGTCGTGCCCGGCAA GGGCGGCGGCACGTGGCAAGGCCAGAATGGCAGGGTCGGGACCGTCACCCTGTTCTGCGATGGCGCCC GCGCCGGCGAGGTGGACATTAGCTACAGGAGGTACGACCTCACCTACAAGCGCGCGGGCGACAAGGCC CCCAGCGGCTGGGTCATGAGCGAGTACCAGATCACCTCGCCGCCGCTCTTGAGCACGGTGCTCACCCG CATCGGATTGATCGTCGCCGCCAGGGAGCAGAGGAAGCGACAGCCGGCCGACCCGGAGGCGTTTGCTC AGCAGGGCCCTCACAAGGTGCTGGCCGTCGCAGCCGCAGCCACCGCTGCCGAACATCAACGGGTTTCA CCAGCGCCAGTGCAGCCAGGCCCTGACCCGCAAGCCGACGATGGTGCTCTCTACCATGGCGATACTAG CGTCACCGGCGTGGGGGAGAACGGCGGGCACTACACGGTTCCGCTTCTGCTCAACGGCCAAGAGTACT ACAAGGACAAGAGCCGCGTCAAACGCAAACGGCGGCGATATGGGGCATGA >Tu NAC (Triticum Urartu) SEQU ENCE I D NO.8

ATGGCGGCGGCGTTCAAGTTCGACCCCACCGACGCCGACATCGTCGCCTCCTACCTCCTCCCCCGCGC GGTCGGCCTCGACGAGCCCCACGGCCACGGGCGCGCCGTCATCGACGACGACCCCATGAGCCTCCCGC CGTGGGACCTCATGGAGAAGCACAACCACGGGACAAGCCACCAGGCCTTCTTCTTCGGGCCTCCCAGG AACGGGGGCCCCGTCAAGCGCGTCGTACCCGGCAAGGGCGGCGGCACGTGGCAAGGGCAGAATGGCAG CGTCGGGACCGTCACCCTGTTCTGCGATGGCGATGGCGATGGCGCCCGCACGGGCGAGGTGGACATCA GCTACAGGAGGTACGACCTCACCTACAAGCGCGCGGGCGACAAGGCCCCCAGCGGCTGGGTCATGAGC GAGTACCAGATCACCTCGCCGCCGCTCTTGAGCACGGTGCTCACCCACATCGGATTGACCGTCGCCGC CAGGGAGCAGAGGAAGCGACAGCCGGCCGACCCGGAGCCGTTTGCTCAGCACGGCCCTGACAAGGTGC TGGCCGTCGCAGCCGCTGCCGCCGCCGCCGCCGAACATCAACGGGTTTCACCACCGCCAGTGCAGTCG GGCCCTGACGCGCAAGCCGACGATGGTGCTCTCTACCATGGCGGTACTAGCGTCACCGGCGTGGGGGA GAACGGTGGGCACTACAATGTTCCGCTTCTGCTCAACGGCCAAGAGTACTACAAGGACAAGAGCCGCG TCAAACGCAAACGGCGGCGATATGGGGCATGA >TtNAC (Triticum turgidum) SEQUENCE I D N0.9

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCGGCGTTCAAGTTCGACCCCACCGACGC CGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTCGACAAGCCCCACGGCCACGGGCGCG CCGTCATCGACGACGACCCCATGAGCCTCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACC AGCGACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCGCGTCAAGCGCGTCGTCAAGGGCGG CGGCATGTGGCAAGGGCAGAATGGCAGGGTCGGGACCGTCACCCTGTTCTGCGATGGCGCCGGCGAGG TGGACATCAGCTACAGGAGGTACGACCTCACCTACAAGCGCGCGGGGAACAAGGACCCCAGCGGCTGG GTCATGAGCGAGTACCAGATCACCTCGCCTCCGTCCTTGAGCACGGTGCTCACCCGCATCGGATTGAC CGTCGCCGCCGGGGAGCAGAGGAAGCGACAGCCGGCCGACCAGGAGGCGTTTGCTCAGCAGGGCCCTG ACAAGGTGCTGGCCGTCGCAGCCGCTGCCGCCGCCGCCGAACATCAACGGGTGTCACCACCGCCATTG AAGTCAGGCCCTGACGCGCAAGCTGACGATGGTGCTCTCTACCATGACGATACTAGCGTCACCGGCGT GGAGGAGAACGGTGGGCACTACACTGTTCCGCTTCTGCTCAACGGCCAAGAGTACTACAAGGACAAGA GCCGCGTCAAACGCAAACGGCGGCGATATGGGGCATGA

>TmNACl (Triticum monococum 1) SEQUENCE ID NO.10

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCAGCGTTCAAGTTCGACCCCACCGACGC CGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTAGACGAGCCCCACGGCCACGGGCGCG CCGTCATCGACGACGACCCCATGAGCCTCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACA AGCCACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCCCGTCAAGCGCGTCGTACCCGGCAA GGGCGGCGGCACGTGGCAAGGGCAGAATGGCAGCGTCGGGACCGTCACCCTGTTCTGCGATGGCGATG GCGATGGCGATGGCGCCCGCGCGGGCGAGGTGGACATCAGCTACAGGAGGTACGACCTCACCTACAAG CGCGCGGGCGACAAGGCCCCCAGCGGCTGGGTCATGAGCGAGTACCAGATCACCTCGCCGCCGCTCTT GAGCACGGTGCTCACCCGCATCGGATTGACCGTCGCCGCCAGGGAGCAGAGGAAGCGACAGCCGGCCG ACCCGGAGCCGTTTGCTCAGCACGGCCCTGACAAGGTGCTGGCCGTCGCAGCCGCGGCCGCCGCCGCC GCCGAACATCAACGGGTTTCACCACCGCCAGTGCAGTCGGGCCCTGACGCGCAAGCCGACGATGGTGC TCTCTACCATGGCGGTACTAGCGTCACCGGCGTGGGGGAGAACGGTGGGCACTACACTGTTCCGCTTC TGCTCAACGGCCAAGAGTACTACAAGGACAAGAGCCGCGTCAAACGCAAACGGCGGCGATATGGGGCA TGA

>TmNAC2 (Triticum monococum 2) SEQUENCE ID NO. ll

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCAGCGTTCAAGTTCGACCCCACCGACGC CGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTAGACGAGCCCCACGGCCACGGGCGCG CCGTCATCGACGACGACCCCATGAGCCTCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACA AGCCACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGGCCCGTCAAGCGCGTCGTACCCGGCAA GGGCGGCGGCACGTGGCAAGGGCAGAATGGCAGCGTCGGGACCGTCACCCTGTTCTGCGATGGCGATG GCGATGGCGATGGCGCCCGCGCGGGCGAGGTGGACATCAGCTACAGGAGGTACGACCTCACCTACAAG CGCGCGGGCGACAAGGCCCCCAGCGGCTGGGTCATGAGCGAGTACCAGATCACCTCGCCGCCGCTCTT GAGCACGGTGCTCACCCGCATCGGATTGACCGTCGCCGCCAGGGAGCAGAGGAAGCGACAGCCGGCCG ACCCGGAGCCGTTTGCTCAGCACGGCCCTGACAAGGTGCTGGCCGTCGCAGCCGCGGCCGCCGCCGCC GCCGAACATCAACGGGTTTCACCACCGCCAGTGCAGTCGGGCCCTGACGCGCAAGCCGACGATGGTGC TCTCCACCATGGCGGTACTAGCGTCACCGGCGTGGGGGAGAACGGTGGGCACTACACTGTTCCGCTTC TGCTCAACGGCCAAGAGTACTACAAGGACAAGAGCCGCGTCAAACGCAAACGGCGGCGATATGGGGCA TGA

The amino acid sequences of the homologs are as follows: >AtNAC (Aegilops taushii) SEQUENCE ID N0.12

MEASRFGFGRDMAAAFKFDPTDAGIVASYLLPRAVGLDEPHGREHAVI DDDPMSI PPWDLMEKHNHGT SDQAFFFGPPRNGGRVTRVVPGKGGGTWQGQNGRVGTVTLFCDGARAGEVDISYRRYDLTYKRAGDKA PSGWVMSEYQITSPPLLSTVLTRIGLIVAAREQRKRQPADPEAFAQQGPHKVLAVAAAATAAEHQRVS PAPVQPGPDPQADDGALYHGDTSVTGVGENGGHYTVPLLLNGQEYYKDKSRVKRKRRRYGA

>TuNAC (Triticum Urartu) SEQUENCE ID N0.13

MAAAFKFDPTDADIVASYLLPRAVGLDEPHGHGRAVIDDDPMSLPPWDLMEKHNHGTSHQAFFFGPPR NGGPVKRWPGKGGGTWQGQNGSVGTVTLFCDGDGDGARTGEVDISYRRYDLTYKRAGDKAPSGWVMS EYQITSPPLLSTVLTHIGLTVAAREQRKRQPADPEPFAQHGPDKVLAVAAAAAAAAEHQRVSPPPVQS GPDAQADDGALYHGGTSVTGVGENGGHYNVPLLLNGQEYYKDKSRVKRKRRRYGA

>TtNAC (Triticum turgidum) SEQUENCE ID NO.14

MEASRFGFGRDMAAAFKFDPTDADIVASYLLPRAVGLDKPHGHGRAVIDDDPMSLPPWDLMEKHNHGT SDQAFFFGPPRNGGRVKRVVKGGGMWQGQNGRVGTVTLFCDGAGEVDI SYRRYDLTYKRAGNKDPSGW VMSEYQITSPPSLSTVLTRIGLTVAAGEQRKRQPADQEAFAQQGPDKVLAVAAAAAAAEHQRVSPPPL KSGPDAQADDGALYHDDTSVTGVEENGGHYTVPLLLNGQEYYKDKSRVKRKRRRYGA

>TmNACl (Triticum monococum 1) SEQUENCE ID N0.15

MEASRFGFGRDMAAAFKFDPTDADIVASYLLPRAVGLDEPHGHGRAVI DDDPMSLPPWDLMEKHNHGT SHQAFFFGPPRNGGPVKRVVPGKGGGTWQGQNGSVGTVTLFCDGDGDGDGARAGEVDISYRRYDLTYK RAGDKAPSGWVMSEYQITSPPLLSTVLTRIGLTVAAREQRKRQPADPEPFAQHGPDKVLAVAAAAAAA AEHQRVSPPPVQSGPDAQADDGALYHGGTSVTGVGENGGHYTVPLLLNGQEYYKDKSRVKRKRRRYGA >TmNAC2 (Triticum monococum 2) SEQUENCE ID NO.16

MEASRFGFGRDMAAAFKFDPTDADIVASYLLPRAVGLDEPHGHGRAVI DDDPMSLPPWDLMEKHNHGT SHQAFFFGPPRNGGPVKRVVPGKGGGTWQGQNGSVGTVTLFCDGDGDGDGARAGEVDISYRRYDLTYK RAGDKAPSGWVMSEYQITSPPLLSTVLTRIGLTVAAREQRKRQPADPEPFAQHGPDKVLAVAAAAAAA AEHQRVSPPPVQSGPDAQADDGALHHGGTSVTGVGENGGHYTVPLLLNGQEYYKDKSRVKRKRRRYGA

As TaNAC5D is a native gene, the risk of resistance breakdown in reduced. Thus, it will be understood that plant material may express some level of endogenous TaNAC5D. Overexpressing TaNAC5D in the plant material provides resistance or enhanced resistance of FHB compared to the plant material which does not overexpress TaNAC5D.

The inventors have shown that overexpression of the gene TaNAC5D provided resistance to the fungal pathogen Fusarium graminearum in wheat plants when compared to wheat plants that did not overexpress TaNAC5D. The inventors have also shown that the gene TaNAC5D provided resistance to the mycotoxin deoxynivalenol (DON) in Arabidopsis. Providing or enhancing resistance to the toxin will in turn improve resistance to disease. Typically, the level of TaNAC5D overexpression is from 20 to 200, or from 50 to 150, times higher in the lines, or plant material, overexpressing TaNAC5D compared to the wild type, i.e. those that were not genetically transformed or manipulated to express TaNAC5D. In one embodiment, the level of TaNAC5D overexpression is from 50 to 95 times higher, or 60, 70, 80, or 90 times higher.

This novel NAC transcription factor is characterised as a nuclear protein that is able to stimulate transcription in yeast. TaNAC5D interacts with stress regulator SKRKI a and the Fusarium Resistance Orphan protein TaFROG as determined by yeast-two hybrid analysis and by biomolecular fluorescence complementation BiFC in planta.

TaNAC5D has a nucleotide sequence of SEQUENCE ID NO. 1 as follows:

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCGGCGTTCAAGTTCGACCCCAC CGACGCCGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTCGACGAGCCCCACG GCCGCGAGCACGCCGTGATCGACGACGACCCCATGAGCATCCCGCCGTGGGACCTCATGGAG AAGCACAACCACGGGACCAGCGACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCG CGTCACGCGCGTCGTGCCCGGCAAGGGCGGCGGCACGTGGCAAGGCCAGAATGGCAGGGTCG GGACCGTCACCCTGTTCTGCGATGGCGCCCGCGCCGGCGAGGTGGACATTAGCTACAGGAGG TACGACCTCACCTACAAGCGCGCGGGCGACAAGGCCCCCAGCGGCTGGGTCATGAGCGAGTA CCAGATCACCTCGCCGCCGCTCTTGAGCACGGTGCTCACCCGCATCGGATTGATCGTCGCCG CCAGGGAGCAGAGGAAGCGACAGCCGGCCGACCCGGAGGCGTTTGCTCAGCAGGGCCCTCAC AAGGTGCTGGCCGTCGCAGCCGCAGCCACCGCTGCCGAACATCAACGGGTTTCACCAGCGCC AGTGCAGCCAGGCCCTGACCCGCAAGCCGACGATGGTGCTCTCTACCATGGCGATACTAGCG TCACCGGCGTGGGGGAGAACGGCGGGCACTACACGGTTCCGCTTCTGCTCAACGGCCAAGAG TACTACAAGGACAAGAGCCGCGTCAAACGCAAACGGCGGCGATATGGGGCATGA TaNAC5D has an amino acid sequence of SEQUENCE ID NO. 2 as follows:

MEASRFGFGRDMAAAFKFDP DADIVASYLLPRAVGLDEPHGREHAVIDDDPMS I PPWDLME KHNHG SDQAFFFGPPRNGGRVTRVVPGKGGGTWQGQNGRVGTVTLFCDGARAGEVDI SYRR YDLTYKRAGDKAPSGWVMSEYQITSPPLLSTVLTRIGLIVAAREQRKRQPADPEAFAQQGPH KVLAVAAAATAAEHQRVSPAPVQPGPDPQADDGALYHGDTSVTGVGENGGHYTVPLLLNGQE YYKDKSRVKRKRRRYGA

In an embodiment of the invention, a variant of the gene is also provided. Typically, said variant has at least about 30% sequence identity with SEQUENCE ID NO. 1 . In an embodiment, the variant has at least about 40%, 50%, 60% or 70 % sequence identity to SEQUENCE ID NO. Un a preferred embodiment, the variant comprises at least about 70, 75, 80, 81 , 82, 83, 84, 85, 86, 87, 88, 89, 90, 91 , 92, 93, 94, 95, 96, 97, 98 or 99% sequence identity with SEQUENCE ID NO. 1. Typically, the variant is a functional variant.

In an embodiment, the variant comprises (or consists of) a nucleotide sequence selected from SEQUENCE ID NO. 3 and SEQUENCE ID NO. 4.

SEQUENCE ID NO. 3 is as follows:

>TaNAC5A-cs

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCGGCGTTCAAGTTCGACCCCACCGACGC CGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTCGACGAGCCCCACGGCCACGGGCGCG CCGTCATCGACGACGACCCCATGAGCCTCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACA AGCCACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCCCGTCAAGCGCGTCGTGCCCGGCAA GGGCGGCGGCACGTGGCAAGGGCAGAATGGCAGCGTCGGGACCGTCACCCTGTTCTGCGATGGCGATG GCGATGGCGCCCGCGCGGGAGAGGTGGACATCAGCTACAGGAGGTACGACCTCACCTACAAGCGCGCG GGCGACAAGGCCCCCAGCGGCTGGGTCATGAGCGAGTACCAGATCACCTCGCCGCCGCTCTTGAGCAC GGTGCTCACCCGCATCGGATTGACCGTCGCCGCCAGGGAGCAGAGGAAGCGACAGCCGGCCGACCCGG AGCCGTTTGCTCAGCACGGCCCTGACAAGGTGCTGGCCGTCGCAGCCGCTGCCGCCGCCGCCGCCGAA CATCAACGGGTTTCACCACCGCCAGTGCAGTCGGGCCCTGACGCGCAAGCCGACGATGGTGCTCTCTA CCATGGCGGTACTAGCGTCACCGGCGTGGGGGAGAACGGTGGGCACTACACTGTTCCGCTTCTGCTCA ACGGCCAAGAGTACTACAAGGACAAGAGCCGCGTCAAACGCAAACGGCCGCGATATGGGGCATGA SEQUENCE ID NO. 4 is as follows:

>Ta NAC5B-cs

ATGGAAGCCTCGCGGTTCGGCTTCGGCCGCGACATGGCGGCGGCGTTCAAGTTCGACCCCACCGACGC CGACATCGTCGCCTCCTACCTCCTCCCCCGCGCGGTCGGCCTCGACAAGCCCCACGGCCACGGGCGCG CCGTCATCGACGACGACCCCATGAGCCTCCCGCCGTGGGACCTCATGGAGAAGCACAACCACGGGACC AGCGACCAGGCCTTCTTCTTCGGGCCTCCCAGGAACGGGGGCCGCGTCAAGCGCGTCGTCAAGGGCGG CGGCATGTGGCAAGGGCAGAATGGCAGGGTCGGGACCGTCACCCTGTTCTGCGATGGCGCCGGCGAGG TGGACATCAGCTACAGGAGGTACGACCTCACCTACAAGCGCGCGGGGAACAAGGACCCCAGCGGCTGG GTCATGAGCGAGTACCAGATCACCTCGCCTCCGCTCTTGAGCACGGTGCTCACCCGCATCGGATTGAC CGTCGCCGCCGGGGAGCAGAGGAAGCGACAGCCGGCCGACCAGGAGGCGTTTGCTCAGCAGGGCCCTG ACAAGGTGCTGGCCGTCGCAGCCGCTGCCGCCGCCGCCGAACATCAACGGGTGTCACCACCGCCATTG AAGTCAGGCCCTGACGCGCAAGCTGACGATGGTGCTCTCTACCATGACGATACTAGCGTCACCGGCGT GGAGGAGAACGGTGGGCACTACACTGTTCCGCTTCTGCTCAACGGCCAAGAGTACTACAAGGACAAGA GCCGCGTCAAACGCAAACGGCGGCGATATGGG GCATGA

A variant of SEQ ID NO. 2 is also provided. Typically, the variant has at least about 30%, 40%, 50%, 60% or 70% sequence identity with SEQUENCE ID NO. 2. In a preferred embodiment, the variant has at least about 70% sequence identity with SEQUENCE ID NO. 2. Preferably, the variant comprises (or consists of) a sequence having at least about 70, 75, 76, 77, 78, 79, 80, 81 , 82, 83, 84, 85, 86, 87, 88, 89, 90, 91 , 92, 93, 94, 95, 96, 97, 98 or 99% sequence identity with SEQUENCE ID NO. 2. Typically, the variant is a functional variant.

In an embodiment, the variant comprises (or consists of) a nucleotide sequence selected from SEQUENCE ID NO. 5 and SEQUENCE ID NO. 6

SEQUENCE ID NO. 5 is as follows:

>TaNAC5A-cs

MEASRFGFGRDMAAAFKFDPTDADIVASYLLPRAVGLDEPHGHGRAVI DDDPMSLPPWDLMEKHNHGT SHQAFFFGPPRNGGPVKRVVPGKGGGTWQGQNGSVGTVTLFCDGDGDGARAGEVDISYRRYDLTYKRA GDKAPSGWVMSEYQITSPPLLSTVLTRIGLTVAAREQRKRQPADPEPFAQHGPDKVLAVAAAAAAAAE HQRVSPPPVQSGPDAQADDGALYHGGTSVTGVGENGGHYTVPLLLNGQEYYKDKSRVKRKRPRYGA

SEQUENCE ID NO. 6 is as follows:

>TaNAC5B-cs

MEASRFGFGRDMAAAFKFDPTDADIVASYLLPRAVGLDKPHGHGRAVI DDDPMSLPPWDLMEKHNHGT SDQAFFFGPPRNGGRVKRVVKGGGMWQGQNGRVGTVTLFCDGAGEVDI SYRRYDLTYKRAGNKDPSGW VMSEYQITSPPLLSTVLTRIGLTVAAGEQRKRQPADQEAFAQQGPDKVLAVAAAAAAAEHQRVSPPPL KSGPDAQADDGALYHDDTSVTGVEENGGHYTVPLLLNGQEYYKDKSRVKRKRRRYGA Also provided is a nucleotide sequence encoding an amino acid sequence according to SEQUENCE ID NO. 2, or a functional variant of said amino acid sequence that has from about 70% to about 99.9% sequence identify with SEQUENCE ID NO.2. Preferably, 75%, 80%, 85%, 90%, or 95% sequence identity. A construct comprising the nucleotide sequence is also provided.

In an embodiment of the invention, a fragment of SEQUENCE ID N0.1 is provided. The fragment is a functional fragment of SEQUENCE ID NO. 1 . In an embodiment, the fragment has from 10 to 3000 contiguous nucleotides preferably about 100, 250, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, 2500 or 2750 nucleotides.

In an embodiment of the invention, a fragment of SEQUENCE ID NO.2 is provided. The fragment is a functional fragment of SEQUENCE ID NO. 2. In an embodiment, the fragment has from about 10 to 1000 contiguous amino acids, preferably about 50, 100, 5 200, 300, 400, 500, 600, 700, 800, or 900 amino acids.

The current invention provides a construct comprising a nucleotide sequence of SEQUENCE ID NO. 1 or a variant thereof or fragment described herein.

The construct may be an expression vector.

The vector may comprise regulatory machinery, for example promoters, terminators, and/or enhancers. The nucleotide may be under the control of a promotor region. The promotor may be a constitutive plant cell specific promotor. It will be appreciated that any suitable plant cell specific promotor known in the art may be used. The promotor may be such that multiple copies of TaNAC5D are produced. The promoter may be selected from but is not limited to the rice actin promotor, maize ubiquitin promotor and the 35S Cauliflower Mosaic Virus promotor. In an embodiment, the vector is a virus, such as a bacteriophage and comprises, in addition to the nucleic acid sequence of the invention, nucleic acid sequences for replication of the bacteriophage, such as structural proteins, promoters, transcription activators and the like. _The vector may be a Ti plasmid. The vector may contain one or more virulence genes, wherein the at least one virulence gene is typically selected from the group consisting of virA, virB, virC, virD, virE, virG, virK and virJ or functional variants thereof. Ideally, at least 6, 7 or 8 of the above virulence genes are contained on the transformation vector. Preferably, at least 6, 7 or 8 of the above virulence genes form part of vector. A functional variant of a virulence gene is a virulence gene that has been genetically modified by, for example, modification of one or more nucleotides, for example, in a process known in the art as "directed evolution".

In an embodiment of the invention, the construct of the invention and described herein may be used to transform plant material or plant host cells to produce a recombinant material or cell in order to express TaNAC5D or synthesize the protein. This provides or enhances FHB resistance in the plant material or cell.

In a further embodiment, a recombinant host cell comprising a construct as described herein is also provided by the current invention. The host cell may be any biological plant cell which can be cultured in medium and used for the expression of a recombinant gene.

The invention also provides a transformation platform comprising a recombinant construct of the invention. Typically, the transformation platform comprises a bacterium capable of mediating cellular transformation.

The invention also provides plant material genetically transformed or modified with a nucleotide, recombinant construct or transformation platform of the invention. In an embodiment, the transformed plant material comprises a transformed cell capable of overexpression of TaNAC5D or a variant thereof. In other words, the host cell overexpresses TaNAC5D or a variant thereof compared to the expression of same of the unmodified host cell.

The transformed plant material or recombinant host cell is resistant or has enhanced resistance (compared to a non-transformed plant or host cell) to FHB. The transformed plant material or recombinant host cell is resistant or has enhanced resistance (compared to a non- transformed plant material or host cell) to DON. The plant material or host cell may be transformed or modified using methods known in the art. In the current invention, the plant material is selected from but not limited to a plant cell, plant cell culture, plant tissue, plant, or seed for a plant. It will be understood that any suitable plant material known in the art may be used. In the current invention, the plant is a cereal. Typically, said cereal is selected from but not limited to the group comprising maize, rice, wheat, barley, sorghum, millet, oats, soybean, rye and an Arabidopsis plant. Preferably, the cereal is wheat.

The plant material may be a transgenic plant. The transgenic plant produced is resistant or has enhanced resistance (compared to a non-transgenic plant) to FHB. Typically, the plant material comprises a plant cell carrying a transgene, in which the transgene comprises the nucleotide of the invention. The invention also relates to a seed, transgenic cell, plant cell culture or plant cell, transgenic plant tissue, transgenic plant material, or stable transgenic plant, generated according to a method of the invention.

The invention also provides a method of genetically transforming a plant material comprising the steps transforming a cell or cells of the plant material with a nucleotide, recombinant construct or transformation platform of the invention. The transformed cell may be capable of overexpression of a nucleotide of the invention. In other words, the host cell overexpresses TaNAC5D compared to expression levels of an unmodified host cell. A genetically transformed plant material is provided.

The invention also provides a method of producing a transgenic plant comprising the steps of genetically transforming a plant material according to a method of the invention as described herein and generating or growing a transformed plant from the transformed plant material. The invention also provides a method of producing a plant material having resistance or enhanced resistance to FHB disease, the method comprising the steps of transforming a plant material with a construct of the invention or a transformation platform according to the invention, and optionally growing the plant material. Preferably, the recombinant construct comprises SEQUENCE ID NO: 1 or a variant thereof. In this manner, a plant which is resistant to FHB may be produced. Typically, the plant shows reduced or an absence of FHB symptoms when infected with Fusarium fungus compared to a non-transgenic plant. The plant or plant material transformed with the construct or transformation platform of the invention may already express endogenous TaNAC5D. This may be at a low level. The transformed or transgenic plant material of the invention and described herein has improved properties. The improved property includes resistance or enhanced resistance to FHB disease, resistance or enhanced resistance to DON, improved yield, improved seed number, improved seed weight, improved resistance to disease, or a combination thereof Host cells are transformed using techniques known in the art such as, but not limited to, electroporation; calcium phosphate base methods; a biolistic technique or by use of a viral vector. After transfection, the nucleotide of the invention is transcribed as necessary and translated. In some embodiments, the synthesized protein is allowed to remain in the host cell and cultures of the recombinant host cell are subsequently used. The current invention also provides a functional marker for FHB resistance. The marker is the TaNAC5D. The marker may be the nucleotide or the peptide of the invention. This provides ways to develop FHB wheat cultivars by marker assisted selection and breeding. A method of determining FHB resistance or a method of selecting FHB wheat cultivar, by detecting or measuring TaNAC5D expression levels, and optionally growing the FHB wheat cultivar, is also provided. An increased level in expression of TaNAC5D compared to the wild type or non- transformed cell is an indication of FHB resistance.

In an embodiment, the traits displayed by the transformed cell function as a selective marker for the successful incorporation of the transgene. It will be appreciated that incorporation of the transgene may be by any method as described herein. The traits may be those of FHB resistance conferred by TaNAC5D. The transformed cell may also be identified by resistance to antibiotic. In other words, the transformed cell is identifiable by virtue of the fact that it is able to grow in conditions that would have previously not been viable. Typically, the antibiotic resistance is selected from resistance to antibiotics such as hygromycin, kanamycin, spectinomycin, tetracycline and ampicillin.

In a preferred embodiment, the transgene is not linked to selectable marker gene and detection of the successful incorporation of the transgene in the transformed plant is by means of PCR / high throughput genetic sequencing for TaNAC5D.

The marker may be the nucleotide sequence of the invention or the amino acid sequence of the invention.

Also provided is plant material genetically transformed according to a method of the invention.

A further aspect of the invention provides an isolated sequence comprising (or consisting of) SEQUENCE ID NO. 1 or a functional variant thereof or a functional fragment thereof. Preferably, the variant has at least 55% sequence identity with SEQUENCE ID No. 1. Preferably, the variant has at least 60% or 70% sequence identity with SEQUENCE ID NO. 1. In a preferred embodiment, the variant has at least about 70%, 75%, 80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity with SEQUENCE ID NO. 1 . A further aspect of the invention provides an isolated peptide comprising (or consisting of) SEQUENCE ID NO. 2 or a functional variant thereof or a functional fragment thereof. The invention also provides an isolated protein encoded by the nucleotide of the invention or having a sequence of SEQUENCE ID NO. 2 or a functional variant thereof or a functional variant thereof. Typically, the variant has at least about 30%, 40%, 50%, 60% or 70% sequence identity to SEQUENCE ID NO. 2. In a preferred embodiment, the variant has at least about 70% sequence identity to SEQUENCE ID NO. 2. Preferably, the variant comprises (or consists of) a sequence having at least about 70%, 75%, 76%, 77%, 78%, 79%, 80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 30 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity with SEQUENCE ID NO. 2.

The invention also relates to a kit of parts capable of genetically transforming a cell, ideally a plant cell, comprising (a) bacteria capable of mediating cellular transformation, (b) a recombinant construct, and (c) a transgene. The transgene may be located on the unitary transformation vector or may be on a different vector.

A further aspect of the invention provides a method for providing or enhancing FHB resistance in a plant material. The method comprises the steps of transforming a plant material with a construct of the invention or a transformation platform according to the invention, and optionally growing the plant material.

The invention also provides a method of increasing tolerance to develop FHB symptoms in a plant material. The method comprises the steps of transforming a plant material with a construct of the invention or a transformation platform according to the invention, and optionally growing the plant material.

MATERIALS AND METHODS

Plant and fungal material

Arabidopsis thaliana accession Col-0 and Triticum aestivum (wheat) cultivar (cv.) Fielder were used in this study. Wheat cv. Fielder is susceptible to FHB disease (Badea et al., 2013). The cv. Fielder and its' transgenic derivatives were used for the disease assessment studies. Wild type F. graminearum strain GZ3639 was used for pathogenicity studies (Bai et al., 2002). Asexual conidial inoculum (macroconidia) was produced in mung bean broth (Bai and Shaner, 1996) and was harvested, washed and adjusted to 10⁶ conidia/ml, all as previously described (Brennan et al., 2005). DNA, RNA extraction and cDNA synthesis

DNA was extracted using the HP plant DNA mini kit (OMEGA) following the manufacturer's instructions. RNA from plant tissues was extracted using the RNeasy plant kit (Qiagen), according to the manufacturer's instructions. DNase treatment of RNA was performed using the TURBO DNA-free kit (Ambion Inc.), according to the manufacturer's instructions. The quality, yield and Integrity of the RNA was analysed by measuring the UV absorbance with a NanoDrop 1000 (Thermo Scientific) and it was visualized following electrophoresis through an agarose gel. The absence of DNA contamination was confirmed by PCR primers targeting the endogenous gene TaGAPDH (primer sets listed in Table 1 ). Reverse transcription of total RNA was performed as described previously (Walter et al., 2008).

Amplification and sequencing of TaNAC5D

The full length coding sequence of TaNAC5D was obtained from cDNA using RNA extracted from DON-treated heads of wheat cv. CM82036 using primers (primer sets listed in Table 1 ) designed from the consensus sequence obtained from a yeast two-hybrid screen (Perochon et al., 2015). RNA was desphophorylated, decapped and reverse transcribed using Superscript™ III RT (Invitrogen), according to manufacturer's instructions. The final extension was set at 68°C for 10 min. Amplified fragments were cloned into the pGEM®-T vector system (Promega) and sequenced. Bioinformatic analysis

Using the sequence obtained from cDNA of TaNAC5D, the open reading frame (ORF) and the coding sequence (CDS) were deduced using NCBI's ORF finder (http://www.ncbi.nlm.nih.gov/gorf/gorf.html). Homologs and homeologs were identified via BLASTn query of the nucleotide sequences in the NCBI GenBank and genome databases of wheat http://wheat-urgi.versailles.inra.fr/Seq-Repository

http://www.cerealsdb.uk.net/cerealgenomics/CerealsDB), Triticum monococum, Triticum urartu and Triticum turgidum (http://dubcovskylab.ucdavis.edu/wheat_blast). Multiple sequence alignments were performed using Multalin (http://multalin.toulouse.inra.fr/multalin/). Generation of transgenic wheat and Arabidopsis plants

Transgenic wheat cv. Fielder overexpressing TaNAC5D was generated as follows: the TaNAC5D CDS was cloned using the gateway cloning strategy (primer sets listed in Table 1 ) and the pDONR207 vector (Invitrogen); the gene was subsequently cloned into binary vector pSc4ActR1 R2 under the control of the rice actin promoter (McElroy et al., 1990). The recombinant plasmid pEW246-7a/V/AC5D was then transformed into Agrobacterium tumefaciens strain AGL-1 and co-cultivated with immature wheat embryos at 23 °C in the dark for 2 days (Ishida et al., 2015). Following removal of the embryonic axis, subsequent tissue culture of the plant material was performed as described previously (Risacher et al., 2009). DNA isolated from regenerated plantlets was analysed by qPCR to determine the copy number of the nptll selectable marker gene, relative to an internal control (Craze et al., in preparation). TO transgenic plants carrying T-DNA (1 copy in lines OE-1 and OE-2) and overexpressing TaNAC5D were propagated to the T3 generation: plants were grown under contained environment conditions at 20-22°C with a 16 h light/8 h dark photoperiod at 300 μηηοΙ nr² s^"1 70% relative humidity, as previously described (Ansari et al., 2007). Homozygosity was analysed by testing for the presence/absence of the construct and calculating the segregation ratio in each generation.

For Arabidopsis transformation, the TaNAC5D coding sequence was fused to hemagglutinin (HA) epitope (TaNAC5D-HA) under the control of the 35S promoter. TaNAC5D CDS was cloned in pDONR207 (Invitrogen) using a gateway cloning strategy (primer sets listed in Table 1 ) and the gene was subsequently cloned into binary vector pAM-PAT-P35S-HA (Bernoux et al., 2008). pAM-PAT-P35S-TaNAC5D-HA was transformed into Arabidopsis ecotype Col-0 via Agrobacterium-mediated transformation using the floral dipping method (Logemann et al., 2006). Transgenic plants were selected in vitro on ½ MS containing 1 % sucrose and BASTA (7.5 μg/ml glufosinate ammonium), pH 5.7. Homozygous lines were propagated to the T4 generation at 20-22°C with a 16 h light/8 h dark photoperiod at 200 μηιοΙ nr² s^"1 and 70% relative humidity. Expression of TaNAC5D was confirmed by qPCR.

FHB assessment

Wheat cv. Fielder and transgenic lines overexpressing TaNAC5D were grown and heads were sprayed with a total of 2 ml inoculum of 2 x 10⁵ conidia/ml of F. graminearum using a hand- held sprayer. Control plants were sprayed with Tween-20 (mock). Spray inoculated heads were covered with plastic bags for 4 days to promote infection. The level of infection was calculated by visually scoring the number of infected spikelets at 7, 14 and 21 days post inoculation and data were used to calculate area under the disease progress curve (AUDPC) (Shaner, 1977). One biological replicate was used including at least 20 heads (10 plants) per treatment.

DON sensitivity assay Arabidopsis seeds were surface-sterilised and sown on medium (½ MS (M0404, Sigma) containing 1 % sucrose, 0.4% gelrite, pH 5.7) with or without 33.8 μΜ DON. After incubation at 4°C in the dark for 48h to synchronise germination, plates were incubated at 20-22°C in a controlled environment with a 16h light/8 h dark photoperiod at 100 μηηοΙ nr² s^"1 and 70% relative humidity. After 14 days of culture for the DON treated plants or at the corresponding developmental stage for the control plants (7 days), the fresh weight of each genotype was measured.

Table 1. Primers used in this study.

Primers Primer sequence (5' to 3') Application

TaNAC5D ATG -27 for GGAACCAAGGAACCATTCGTTTGC (SEQ Cloning TaNAC5D CDS

ID 17)

TaNAC5D TGA +89 GGAATGTCGAGAACCAAGGATCC (SEQ

rev ID 18)

TaNAC5D M1 monocot GGGGACAAGTTTGTACAAAAAAGCAGG Cloning TaNAC5D into for GWY CTCCACCATGGAAGCCTCGCGGTTCG pSc4ActR1 R2

(SEQ ID 19)

TaNAC5D M1 for GWY GGAGATAGAACCATGGAAGCCTCGCGG Cloning TaNAC5D into

TTCG (SEQ ID 20) pDONR207

TaNAC5D +Stop Rev CAAG AAAG CTGG GTCTCATG CCCCATAT Cloning TaNAC5D into GWY CGCCGCCGT (SEQ ID 21 ) pDONR207 and pSc4ActR1 R2

attB1 GGGGACAAGTTTGTACAAAAAAGCAGG Cloning into pDONR207

CTTCG AAG G AG ATAG AACCATG (SEQ ID

22)

attB2 GGGGACCACTTTGTACAAGAAAGCTGG

GTC (SEQ ID 23)

pDONR207 for TCGCGTTAACGCTAGCATGGATCTC Sequencing pDONR207

(SEQ ID 24)

pDONR207 rev GTAACATCAGAGATTTTGAGACAC (SEQ

ID 25)

TaGAPDH for CCTTCCGTGTTCCCACTGTTG (SEQ ID Control DNA contamination

26) in RNA samples

TaGAPDH rev ATGCCCTTGAGGTTTCCCTC (SEQ ID 27)

pEW246 NOS rev CCGCCCGATCTAGTATCATA (SEQ ID 28) Confirmation T-DNA insertion in Wheat pAM-PAT Prom for TCCCACTATCCTTCGCAAGACC (SEQ ID Confirmation T-DNA

29) insertion in Arabidopsis pAM-PAT Ter rev GGATAGCCCGCATAGTCAGGAA (SEQ ID

30)

TaAlpha-tubulin for ATCTCCAACTCCACCAGTGTCG (SEQ ID qRT-PCR

31 )

TaAlpha-tubulin rev TCATCGCCCTCATCACCGTC

(SEQ ID 32)

TaNAC5D for ACTACACG GTTCCG CTTCTG (SEQ ID 33)

TaNAC5D rev GCGGCTCTTGTCCTTGTAGT (SEQ ID 34)

Results and Discussion TaNAC5D is a divergent NAC transcription factor taxonomically-restricted to the Triticeae

In order to identify downstream signalling of the wheat fusarium resistance orphan protein TaFROG (Perochon et al., 2015), a yeast two hybrid screen was conducted and thus identified a full-length open reading frame of the Triticum aestivum NAC transcription factor chromosome 5D gene (TaNAC5D) from bread wheat cv. CM82036. The deduced coding sequence shares 100, 95 and 94% homology with sequences on chromosomes 5D, 5A and 5B, respectively, of the published wheat cv. Chinese Spring genome ((IWGSC), 2014) (Fig. 1 ). TaNAC5D homologs were found within and restricted to the Triticeae tribe (E<10^"152) of Pooideae subfamily of grasses (Fig. 2A and B). In barley and brachypodium two closed proteins were found with 56 and 46% identity, however phylogenic distribution and protein domain analyses excluded then from the TaNAC5D group.

Effect of TaNAC5D on Arabidopsis resistance to DON

In order to understand how TaNAC5D participate to DON resistance, Arabidopsis thaliana transgenic lines expressing TaNAC5D under the control of the CaMV 35S promoter were generated using the pAM-PAT vector (there is no endogenous TaNAC5D homolog in Arabidopsis). Three independent homozygous lines named OE-1 , OE-2 and OE-3 were used in this study. First characterised to verify the presence of the T-DNA by PCR, the transgenic lines were then confirmed for the correct TaNAC5D overexpression by qPCR. These 7a/V/AC5D-expressing lines exhibit no morphological or developmental alteration under normal plant growth conditions. DON is known to reduce plant growth when applied at the seedling stage. To test if the expression of TaNAC5D increase the plant resistance to DON, the seedling fresh weight after 14 days growth on medium containing DON was measured. No major difference in condition control (no DON) was observed between the different plants. All the transgenic lines (OE-1 , OE-2 and OE-3) when grown on medium containing DON present significant higher fresh weight (13 - 29%) compare to the wild type (Fig. 3). The results demonstrate that TaNAC5D enhances plant resistance to the mycotoxin DON. TaNAC5D enhances wheat resistance to F. graminearum

To test the role of TaNAC5D in FHB resistance in wheat, wheat transgenic lines overexpressing TaNAC5D under the control of the rice actin promoter were analysed. Two independent homozygous lines were generated using the pSc4ActR1 R2 vector and named OE-1 and OE-2. First characterised to verify the presence of the T-DNA by PCR, the transgenic lines were then confirmed for the correct TaNAC5D overexpression by qPCR (Fig. 4). The effect of TaNAC5D overexpression on the spread of FHB symptoms from sprayed whole wheat heads with the pathogen was evaluated. Results showed that wild type cv. Fielder had 98% diseased spikelets at 21 days post-treatment. Transgenic lines exhibited less disease symptoms; significant reductions of 22 and 25% were respectively observed for OE- 1 and OE-2, relative to wild type plants. Additionally, the disease progression (AUDPC) calculated using disease scores from 7, 14 and 21 dpi, was significantly lower for the transgenic lines than on wild type plants (Fig. 5). The results of spray inoculation experiments demonstrated that overexpression of TaNAC5D provided quantitative resistance to FHB.

Claims

Claims

1 . A recombinant construct comprising a nucleotide sequence of SEQUENCE ID NO. 1 or a functional variant thereof having at least 93% sequence identity with SEQUENCE ID NO:

1 . operably linked to a promoter region that is functional in a plant cell.

2. The recombinant construct of Claim 1 , in which the functional variant is a homolog or homeolog of TaNAC5D-cm (SEQUENCE ID NO: 1 )

3. The recombinant construct of any one of the preceding Claims, in which the homolog of TaNAC5D is derived from a wheat (Triticum) or grass (Aestivum) plant.

4. The recombinant construct of Claim 3, in which the homolog comprises a nucleotide sequence selected from the group consisting of SEQUENCE ID NO's 7 to 1 1 .

5. The recombinant construct of Claim 2, in which the homeolog of TaNAC5D comprises a nucleotide sequence selected from the group consisting of SEQUENCE ID NO's 3 and 4.

6. A plant material comprising a recombinant construct of any one of Claims 1 to 5 stably integrated into the genome of the plant material.

7. The plant material of Claim 6, wherein the plant material is capable of overexpression of a nucleotide of SEQUENCE ID NO. 1 , a functional variantthereof.

8. The plant material of Claim 6 or 7, selected from the group consisting of: a plant cell, plant cell culture, plant tissue, plant seed and a plant.

9. The plant material of any of Claims 6 to 8, in which the plant material is a cereal plant material optionally selected from wheat, barley and oat.

10. A method of genetically transforming a plant material comprising at least one plant cell, the method comprising the step of transforming the at least one plant cell with a recombinant construct of any one of Claims 1 to 5.

1 1 . The method of Claim 10, wherein the transformed cell is capable of overexpression of a nucleotide of SEQUENCE ID NO. 1 or a functional variant thereof.

12. A method of producing a plant or plant material having resistance to FHB disease and/or DON, the method comprising the steps of transforming a plant or plant material with a recombinant construct of any one of Claims 1 to 5, and growing the plant or plant material.

13. An isolated nucleotide comprising a sequence of SEQUENCE ID NO. 1 or a functional variant thereof having at least 93% sequence identity with SEQUENCE ID NO: 1.

14. An isolated nucleotide consisting of a sequence of SEQUENCE ID NO. 1 or a functional variant thereof having at least 93% sequence identity with SEQUENCE ID NO: 1

15. The isolated nucleotide of Claim 13 or 14, in which the functional variant is a homolog or homeolog of TaNAC5D-cm (SEQUENCE ID NO: 1 )

16. The isolated nucleotide of Claim 15, in which the homolog of TaNAC5D-cm is derived from a wheat (Triticum) or grass (Aestivum) plant.

17. The isolated nucleotide of Claim 16, in which the homolog of TaNAC5D-cm of selected from the group consisting of SEQUENCE ID NO's 7 to 1 1 .

18. The isolated nucleotide of Claim 15, in which the homeolog of TaNAC5D-cm is selected from the group consisting of SEQUENCE ID NO's 3 and 4.

19. An isolated peptide comprising a sequence of SEQUENCE ID NO. 2 or a functional variant thereof having at least 93% sequence identity with SEQUENCE ID NO: 2.