TaSYP71, a Qc-SNARE, Contributes to Wheat Resistance against Puccinia striiformis f. sp. tritici.
TaSYP71, a Qc-SNARE, Contributes to Wheat Resistance against Puccinia striiformis f. sp. tritici.
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TaSYP71 是一种 Qc-SNARE，有助于提高小麦对条锈菌的抗性。
DOI：
10.3389/fpls.2016.00544
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发表时间：
2016
影响因子：
5.6
通讯作者：
Kang Z
中科院分区：
文献类型：
--
作者：
Liu M;Peng Y;Li H;Deng L;Wang X;Kang Z
N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）参与植物抗性;然而，SYP 71在植物-病原体相互作用的调节中的作用尚不清楚。在这项研究中，我们在小麦TaSYP 71中鉴定了一个植物特异性SNARE，它包含一个Qc-SNARE结构域。三个同源物位于染色体1AL、1BL和1DL上。利用农杆菌介导的瞬时表达技术，将TaSYP 71定位于本氏烟草的质膜上。实时荧光定量PCR分析表明，TaSYP 71同源基因在NaCl、H2 O2胁迫以及强毒和无毒条锈菌（Puccinia striiformis f.）（Pst）分离物。TaSYP 71在裂殖酵母中的异源表达提高了对H2 O2的耐受性。同时，H2 O2处理后，TaSYP 71基因沉默植株中的H2 O2清除基因（TaCAT）表达量明显低于对照，表明TaSYP 71可能通过影响TaCAT基因的表达，消除过量的H2 O2积累，从而提高了对H2 O2胁迫的耐受性。当TaSYP 71同源基因在小麦中被病毒诱导的基因沉默系统全部沉默时，小麦植株对Pst更敏感，侵染面积更大，吸器数量更多，但小麦叶肉细胞坏死面积更大，这可能是TaSYP 71被沉默时，对Pst的抗性贡献较小，不足以阻止病原菌的扩展，坏死面积随病原菌生长而扩大。当然，不能排除后期细胞死亡。此外，在TaSYP 71沉默的小麦植株中，病程相关基因的表达下调。这些结果表明TaSYP 71在小麦抗Pst中起着积极的作用。
N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are involved in plant resistance; however, the role of SYP71 in the regulation of plant–pathogen interactions is not well known. In this study, we characterized a plant-specific SNARE in wheat, TaSYP71, which contains a Qc-SNARE domain. Three homologs are localized on chromosome 1AL, 1BL, and 1DL. Using Agrobacterium-mediated transient expression, TaSYP71 was localized to the plasma membrane in Nicotiana benthamiana. Quantitative real-time PCR assays revealed that TaSYP71 homologs was induced by NaCl, H2O2 stress and infection by virulent and avirulent Puccinia striiformis f. sp. tritici (Pst) isolates. Heterologous expression of TaSYP71 in Schizosaccharomyces pombe elevated tolerance to H2O2. Meanwhile, H2O2 scavenging gene (TaCAT) was downregulated in TaSYP71 silenced plants treated by H2O2 compared to that in control, which indicated that TaSYP71 enhanced tolerance to H2O2 stress possibly by influencing the expression of TaCAT to remove the excessive H2O2 accumulation. When TaSYP71 homologs were all silenced in wheat by the virus-induced gene silencing system, wheat plants were more susceptible to Pst, with larger infection area and more haustoria number, but the necrotic area of wheat mesophyll cells were larger, one possible explanation that minor contribution of resistance to Pst was insufficient to hinder pathogen extension when TaSYP71 were silenced, and the necrotic area was enlarged accompanied with the pathogen growth. Of course, later cell death could not be excluded. In addition, the expression of pathogenesis-related genes were down-regulated in TaSYP71 silenced wheat plants. These results together suggest that TaSYP71 play a positive role in wheat defense against Pst.