Key Laboratory of Pest Monitoring and Green Management, MOA, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China.
Sci Rep. 2017 May 30;7(1):2474. doi: 10.1038/s41598-017-02643-x.
Metabolomic and transcriptomic approaches were used to dissect the enhanced disease resistance in the plants harbouring a RNA interfering construct of OsWRKY62 and OsWRKY76 (dsOW62/76) genes. The primary metabolic pathways were activated in dsOW62/76 compared with wild-type (ZH17) plants, revealed by increased accumulation of amino acids and constituents of citric acid cycle etc. Contents of phenolic acids derived from phenylpropanoid pathway were elevated in dsOW62/76 plants. Importantly, phenolamides, conjugates of the phenolic acids with amines, were detected in large number and mostly at higher levels in dsOW62/76 compared with ZH17 plants; however, the free pools of flavonoids were mostly decreased in dsOW62/76. Salicylic acid (SA) and jasmonic acid (JA)/JA-Ile contents were increased in dsOW62/76 and knockout lines of individual OsWRKY62 and OsWRKY76 genes. Transcription of isochorismate synthase (OsICS1) gene was suppressed in dsOW62/76 and in MeJA-treated rice plants, whereas the transcription level of cinnamoyl-CoA hydratase-dehydrogenase (OsCHD) gene for β-oxidation in peroxisome was increased. The calli with OsCHD mutation showed markedly decreased SA accumulation. These results indicate that OsWRKY62 and OsWRKY76 function as negative regulators of biosynthetic defense-related metabolites and provide evidence for an important role of phenylpropanoid pathway in SA production in rice.
采用代谢组学和转录组学方法剖析了含有 OsWRKY62 和 OsWRKY76（dsOW62/76）基因 RNA 干扰构建体的植物增强的抗病性。与野生型（ZH17）植物相比，dsOW62/76 中初级代谢途径被激活，这表现在氨基酸和柠檬酸循环等成分的积累增加。来自苯丙烷途径的酚酸含量在 dsOW62/76 植物中升高。重要的是，dsOW62/76 植物中检测到大量的酚酰胺，即酚酸与胺的缀合物，且大多高于 ZH17 植物；然而，dsOW62/76 中的游离黄酮类化合物大部分减少。dsOW62/76 和单个 OsWRKY62 和 OsWRKY76 基因敲除系中水杨酸（SA）和茉莉酸（JA）/JA-Ile 的含量增加。dsOW62/76 和 MeJA 处理的水稻植物中异亮氨酸合酶（OsICS1）基因的转录受到抑制，而过氧化物体中β-氧化的肉桂酰辅酶 A 水合酶-脱氢酶（OsCHD）基因的转录水平增加。OsCHD 突变的愈伤组织中 SA 积累明显减少。这些结果表明，OsWRKY62 和 OsWRKY76 作为生物合成防御相关代谢物的负调节剂发挥作用，并为苯丙烷途径在水稻中 SA 产生中的重要作用提供了证据。
