Overexpression of arginase in Arabidopsis thaliana influences defence responses against Botrytis cinerea
Overexpression of arginase in Arabidopsis thaliana influences defence responses against Botrytis cinerea
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DOI：
10.1111/j.1438-8677.2011.00520.x
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发表时间：
2012-03-01
期刊：
影响因子：
3.9
通讯作者：
Angenon, G.
中科院分区：
文献类型：
--
作者：
Brauc, S.;De Vooght, E.;Angenon, G.
拟南芥具有两个精氨酸酶编码基因ARGAH1和ARGAH2，催化精氨酸分解代谢为鸟氨酸和尿素。精氨酸和鸟氨酸都是多胺生物合成途径的前体。我们观察到，在接种坏死性病原菌灰霉病菌后，ARGAH2基因在拟南芥中积累。建立了高表达ARGAH2或同时沉默两个拟南芥精氨酸酶编码基因的转基因株系，并评价了它们对灰霉病菌侵染的抗性。精氨酸酶的过度表达导致氨基酸积累的变化，而多胺水平基本上没有受到影响。沉默品系的氨基酸和腐胺积累均受到影响。过量表达精氨酸酶基因的拟南芥植株对灰霉病的敏感性较低，而沉默品系与野生型一样敏感。我们讨论了精氨酸酶如何与植物防御机制相互作用。这些结果为研究应激状态下氨基酸代谢的变化提供了新的见解。
Arabidopsis possesses two arginase-encoding genes, ARGAH1 and ARGAH2, catalysing the catabolism of arginine into ornithine and urea. Arginine and ornithine are both precursors for polyamine biosynthetic pathways. We observed an accumulation of ARGAH2 mRNA in Arabidopsis upon inoculation with the necrotrophic pathogen Botrytis cinerea. Transgenic lines displaying either overexpression of ARGAH2 or simultaneous silencing of both Arabidopsis arginase-encoding genes were created and their resistance to B. cinerea infection evaluated. Overexpression of arginase resulted in changes in amino acid accumulation, while polyamine levels remained largely unaffected. Silencing lines were affected in both amino acid and putrescine accumulation. Arabidopsis plants overexpressing the arginase gene were less susceptible to B. cinerea, whereas silencing lines remained as susceptible as the wild type. We discuss how arginase might interact with plant defence mechanisms. These results provide new insights into amino acid metabolic changes under stress.