Barley is an important cereal crop worldwide because of its use in the brewing and distilling industry. However, adequate supplies of quality malting barley are threatened by global climate change due to drought in some regions and excess precipitation in others, which facilitates epidemics caused by fungal pathogens. The disease net form net blotch caused by the necrotrophic fungal pathogen Pyrenophora teres f. teres (Ptt) has emerged as a global threat to barley production and diverse populations of Ptt have shown a capacity to overcome deployed genetic resistances. The barley line CI5791 exhibits remarkably effective resistance to diverse Ptt isolates from around the world that maps to two major QTL on chromosomes 3H and 6H. To identify genes involved in this effective resistance, CI5791 seed were γ-irradiated and two mutants, designated CI5791-γ3 and CI5791-γ8, with compromised Ptt resistance were identified from an M₂ population. Phenotyping of CI5791-γ3 and -γ8 × Heartland F₂ populations showed three resistant to one susceptible segregation ratios and CI5791-γ3 × -γ8 F₁ individuals were susceptible, thus these independent mutants are in a single allelic gene. Thirty-four homozygous mutant (susceptible) CI5791-γ3 × Heartland F₂ individuals, representing 68 recombinant gametes, were genotyped via PCR genotype by sequencing. The data were used for single marker regression mapping placing the mutation on chromosome 3H within an approximate 75 cM interval encompassing the 3H CI5791 resistance QTL. Sequencing of the mutants and wild-type (WT) CI5791 genomic DNA following exome capture identified independent mutations of the HvWRKY6 transcription factor located on chromosome 3H at ∼50.7 cM, within the genetically delimited region. Post transcriptional gene silencing of HvWRKY6 in barley line CI5791 resulted in Ptt susceptibility, confirming that it functions in NFNB resistance, validating it as the gene underlying the mutant phenotypes. Allele analysis and transcript regulation of HvWRKY6 from resistant and susceptible lines revealed sequence identity and upregulation upon pathogen challenge in all genotypes analyzed, suggesting a conserved transcription factor is involved in the defense against the necrotrophic pathogen. We hypothesize that HvWRKY6 functions as a conserved signaling component of defense mechanisms that restricts Ptt growth in barley.

由于大麦在酿造和蒸馏行业中的使用，大麦是全世界重要的谷物作物。然而，由于某些地区的干旱和其他地区的过量降水，全球气候变化威胁着充足的优质大麦大麦供应，这促进了由真菌病原体引起的流行病。坏死性真菌病原体引起的疾病网状网斑斑节对虾 F。 特雷斯 （点）已成为对大麦生产和全球不同种群的全球威胁 点已显示出克服已部署的遗传抗性的能力。大麦系CI5791对多种植物表现出显着的有效抗性点来自世界各地的分离株，它们映射到3H和6H染色体上的两个主要QTL。为了鉴定参与此有效抗性的基因，对CI5791种子进行了γ射线辐照，并命名了两个突变体，分别命名为CI5791-γ3和CI5791-γ8。点从M ₂种群中鉴定出抗药性。CI5791-γ3和-γ8×Heartland F ₂种群的表型显示对一种敏感的分离比具有三种抗性，而CI5791-γ3×-γ8F ₁个体易感，因此这些独立的突变体位于单个等位基因中。34个纯合突变体（易感）CI5791-γ3×心地F ₂通过PCR基因型通过测序对代表68个重组配子的个体进行基因分型。数据用于单标记回归作图，将突变置于3H染色体上约75 cM的区间内，包括3H CI5791抗性QTL。外显子组捕获后突变体和野生型（WT）CI5791基因组DNA的测序确定了该突变体的独立突变HvWRKY6转录因子位于3H染色体上〜50.7 cM，位于遗传定界区域内。转录后基因沉默HvWRKY6 大麦品系CI5791导致 点易感性，证实其在NFNB抗性中起作用，从而将其确认为突变表型的基础基因。等位基因分析和转录调控HvWRKY6从抗性和易感株系中分离出的序列揭示了在分析的所有基因型中病原体攻击后的序列同一性和上调，表明保守的转录因子参与了对坏死性病原体的防御。我们假设HvWRKY6 作为防御机制的保守信号成分，可以限制 点 大麦的增长。