Identification of the Vb Gene Which Confers Sensitivity to the Host-Selective Toxin, Victorin

鉴定赋予对宿主选择性毒素 Victorin 敏感性的 Vb 基因

• 批准号: 9631442
• 负责人: Thomas Wolpert
• 金额: $ 30万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9631442&HistoricalAwards=false
• 关键词: Identification; Vb; Gene; Confers; Sensitivity

9631442 Wolpert Victoria blight of oats is caused by the fungus Cochliobolus victoriae. This fungus is pathogenic because it produces the host-specific toxin, victorin. In the host, sensitivity to victorin, and thus, susceptibility to the pathogen, is conditioned by the dominant allele at the Vb locus. It has been hypothesized that the Vb gene conditions susceptibility by coding for a toxin "receptor" (site of action) which is functional in toxin-sensitive lines (susceptible lines) and either absent or altered in toxin-insensitive lines. Biologically-active, labeled derivatives of the toxin have been used to identify and 100 kDa protein that binds victorin only in toxin-sensitive (susceptible) genotypes of oats and a 15 kDa protein that binds victorin in both susceptible and resistant genotypes. The 100 kDa victorin-binding protein (VBP) has been identified as the P-protein component of the nuclear-encoded, mitochondrial multienzyme complex, glycine decarboxylase. Results have also indicated that the 15 kDa H-protein component of the glycine decarboxylase complex (GDC) is a VBP. This research will test a biochemical model that toxin specificity is regulated by the interaction of the two victorin binding proteins, the P- and the H-protein components of the GDC. The results will provide new information about the nature of Host-specific toxin dependent plant disease, which may lead to a new crop protection strategy.

燕麦的Wolpert Victoria疫病是由真菌引起的。这种真菌是致病性的，因为它产生宿主特有的毒素，维多利。在宿主中，对维多利的敏感性以及对病原体的易感性是由Vb位点的显性等位基因决定的。据推测，Vb基因通过编码毒素“受体”（作用位点）来调节易感性，该受体在毒素敏感系（易感系）中起作用，而在毒素不敏感系中缺失或改变。该毒素的生物活性标记衍生物已被用于鉴定仅在毒素敏感（易感）基因型中结合victorin的100 kDa蛋白和在易感和抗性基因型中结合victorin的15 kDa蛋白。100 kDa的victorin结合蛋白（VBP）已被确定为核编码的线粒体多酶复合物甘氨酸脱羧酶的p蛋白成分。结果还表明，甘氨酸脱羧酶复合物（GDC）的15 kDa h蛋白组分是VBP。本研究将检验一种生化模型，即毒素特异性是由两种victorin结合蛋白（GDC的P-和h -蛋白成分）的相互作用调节的。该研究结果将提供有关寄主特异性毒素依赖植物病害性质的新信息，从而可能导致新的作物保护策略。