Mochizuki Tomofumi, Ogata Yoshiyuki, Hirata Yuki, Ohki Satoshi T
Mol Plant Pathol. 2014 Apr;15(3):242-54. doi: 10.1111/mpp.12081.
Cucumber mosaic virus (CMV) causes mosaic disease in inoculated tobacco plants. Coat protein (CP) is one of the major virulence determinants of CMV, and an amino acid substitution at residue 129 in CP alters the severity of chlorosis, such as pale green chlorosis and white chlorosis, in symptomatic tissues of mosaic leaves of infected tobacco. In this study, we compared the transcriptomes of chlorotic tissues infected with the wild-type pepo strain of CMV and two strains carrying CP mutants with diverse chlorosis severity. Differential gene expression analysis showed that CMV inoculation appeared to have similar effects on the transcriptional expression profiles of the symptomatic chlorotic tissues, and only the magnitude of expression differed among the different CMVs. Gene ontology analysis with biological process and cellular component terms revealed that many nuclear genes related to abiotic stress responses, including responses to cadmium, heat, cold and salt, were up-regulated, whereas chloroplast- and photosynthesis-related genes (CPRGs) were down-regulated, in the chlorotic tissues. Interestingly, the level of CPRG down-regulation was correlated with the severity of chlorosis. These results indicate that CP mutation governs the repression level and mRNA accumulation of CPRGs, which are closely associated with the induction of chlorosis.
黄瓜花叶病毒（CMV）在接种的烟草植株中引发花叶病。外壳蛋白（CP）是CMV的主要毒力决定因素之一，CP中第129位氨基酸的替换会改变感染烟草花叶叶片症状组织中的褪绿严重程度，如淡绿色褪绿和白色褪绿。在本研究中，我们比较了感染CMV野生型pepo株系以及携带具有不同褪绿严重程度的CP突变体的两个株系的褪绿组织的转录组。差异基因表达分析表明，CMV接种似乎对症状性褪绿组织的转录表达谱有相似的影响，不同CMV之间仅表达量有所不同。使用生物学过程和细胞成分术语进行的基因本体分析表明，在褪绿组织中，许多与非生物胁迫反应相关的核基因，包括对镉、热、冷和盐的反应，均上调，而与叶绿体和光合作用相关的基因（CPRG）则下调。有趣的是，CPRG下调的程度与褪绿的严重程度相关。这些结果表明，CP突变控制着CPRG的抑制水平和mRNA积累，而CPRG与褪绿的诱导密切相关。
