The role of the wheat Reduced height (Rht)-DELLA mutants and associated hormones in infection by Claviceps purpurea, the causal agent of ergot.
The role of the wheat Reduced height (Rht)-DELLA mutants and associated hormones in infection by Claviceps purpurea, the causal agent of ergot.
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DOI：
10.1094/phyto-05-21-0189-r
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发表时间：
2021-10
期刊：
影响因子：
3.2
通讯作者：
Eleni Tente;Esther Carrer;A. Gordon;L. Boyd
中科院分区：
文献类型：
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作者：
Eleni Tente;Esther Carrer;A. Gordon;L. Boyd
对麦角菌病原菌麦角菌（Claviceps purpurea）的部分抗性已被发现与小麦染色体4 B和4D上的降低高度（Rht）基因座的突变等位基因共定位。这些Rht基因座代表拟南芥Della基因的小麦直向同源物。为了研究Rht突变DELLA蛋白在麦角抗性中的作用，我们评估了C.小麦赤霉素（GA）不敏感半矮秆等位基因Rht-B1 b和Rht-D1 b以及严重矮秆等位基因Rht-B1 c和Rht-D1c的近等基因系（NILs）中的purpurea感染。还包括GA敏感等位基因Rht 8（染色体2D）和Rht 12（染色体5A）的近等基因。对C.在近等基因系Rht-B1 b、Rht-D1 b、Rht-B1 c和Rht-D1c以及Rht 8上均观察到了具有较小和较轻菌核的紫色菌核。接种C. purpurea，遵循类似的模式，暗示潜在的生长素介导的GA生物合成的诱导。与此相反，茉莉酸（JA）水平下降，在亲本系Mercia和Maris亨茨曼接种C。purpurea，但增加了所有的Rht突变近等基因系。接种C.紫花苜蓿在水杨酸水平上没有显示出任何有意义的变化。我们的研究结果表明，GA介导的DELLA蛋白的降解和JA信号通路的下调支持小麦感染C。紫花。由于这些反应通常与坏死营养型真菌病原体有关，我们建议生养型C。紫花苜蓿可能具有坏死营养生长阶段。
Partial resistance to the biotrophic fungal pathogen Claviceps purpurea, causal agent of ergot, has been found that co-locates with mutant alleles of the wheat Reduced height (Rht) loci on chromosomes 4B and 4D. These Rht loci represent the wheat orthologues of the Arabidopsis Della genes. To investigate the role of the Rht mutant DELLA proteins in ergot resistance we assessed C. purpurea infection in wheat near-isogenic lines (NILs) carrying the gibberellic acid (GA)-insensitive semi-dwarf alleles Rht-B1b and Rht-D1b and the severe dwarf alleles Rht-B1c and Rht-D1c. NILs of the GA-sensitive alleles Rht8 (chromosome 2D) and Rht12 (chromosome 5A) were also included. A general trend towards increased resistance to C. purpurea, with smaller and lighter sclerotia, was observed on the NILs Rht-B1b, Rht-D1b, Rht-B1c and Rht-D1c, but also on Rht8. Levels of the bioactive GA4 and the auxin indole-3-acetic acid (IAA) increased following inoculation with C. purpurea, following similar patterns and implicating a potential auxin-mediated induction of GA biosynthesis. In contrast, jasmonic acid (JA) levels fell in the parental lines Mercia and Maris Huntsman following inoculation with C. purpurea, but increased in all the Rht-mutant NILs. Inoculation with C. purpurea did not show any informative changes in the levels of salicylic acid. Our results suggest that GA-mediated degradation of the DELLA proteins and down-regulation of JA-signalling pathways supports infection of wheat by C. purpurea. As these responses are generally associated with necrotrophic fungal pathogens, we propose that the biotroph C. purpurea may have a necrotrophic growth stage.