Pathogen-Plant Interactions Group, Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Virol J. 2011 Jul 18;8:355. doi: 10.1186/1743-422X-8-355.
Clover yellow vein virus (ClYVV) causes lethal systemic necrosis in legumes, including broad bean (Vicia faba) and pea (Pisum sativum). To identify host genes involved in necrotic symptom expression after ClYVV infection, we screened cDNA fragments in which expression was changed in advance of necrotic symptom expression in broad bean (V. faba cv. Wase) using the differential display technique and secondarily with Northern blot analysis. Expression changes were confirmed in 20 genes, and the six that exhibited the most change were analyzed further. These six genes included a gene that encodes a putative nitrate-induced NOI protein (VfNOI), and another was homologous to an Arabidopsis gene that encodes a glycine- and proline-rich protein GPRP (VfGPRP). We recently reported that necrotic symptom development in ClYVV-infected pea is associated with expression of salicylic acid (SA)-dependent pathogenesis-related (PR) proteins and requires SA-dependent host responses. Interestingly, VfNOI and VfGPRP expression was correlated with that of the putative SA-dependent PR proteins in ClYVV-infected broad bean. However, broad bean infected with a recombinant ClYVV expressing the VfGPRP protein showed weaker symptoms and less viral multiplication than that infected with ClYVV expressing the GFP protein. These results imply that VfGPRP plays a role in defense against ClYVV rather than in necrotic symptom expression.
三叶草黄脉病毒 (ClYVV) 可导致豆类（包括蚕豆和豌豆）发生致命的系统性坏死。为了鉴定豆类感染 ClYVV 后与坏死症状表达相关的宿主基因，我们利用差异显示技术，在蚕豆（品种 Wase）坏死症状出现之前筛选出表达发生改变的 cDNA 片段，并用 Northern blot 分析进行了二次筛选。在 20 个基因中发现了表达变化，对其中变化最明显的 6 个基因进行了进一步分析。这 6 个基因包括一个编码拟硝酸诱导的 NOI 蛋白（VfNOI）的基因，另一个基因与拟南芥编码富含甘氨酸和脯氨酸的蛋白 GPRP（VfGPRP）的基因同源。我们最近报道，豌豆感染 ClYVV 后坏死症状的发展与水杨酸（SA）依赖的病程相关（PR）蛋白的表达有关，需要 SA 依赖的宿主反应。有趣的是，VfNOI 和 VfGPRP 的表达与 ClYVV 感染的蚕豆中假定的 SA 依赖 PR 蛋白的表达相关。然而，感染表达 VfGPRP 蛋白的重组 ClYVV 的蚕豆表现出比感染表达 GFP 蛋白的 ClYVV 更弱的症状和更少的病毒复制。这些结果表明 VfGPRP 在抵抗 ClYVV 方面发挥作用，而不是在坏死症状表达中发挥作用。
