Conserved functions of Arabidopsis and rice CC-type glutaredoxins in flower development and pathogen response.
Conserved functions of Arabidopsis and rice CC-type glutaredoxins in flower development and pathogen response.
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DOI：
10.1093/mp/ssn078
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发表时间：
2009-03
期刊：
影响因子：
27.5
通讯作者：
Zhen Wang;S. Xing;R. Birkenbihl;S. Zachgo
中科院分区：
文献类型：
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作者：
Zhen Wang;S. Xing;R. Birkenbihl;S. Zachgo
谷氧还蛋白 (GRX) 是普遍存在的氧化还原酶，通过减少各种生物体中的二硫化物，在应对氧化应激方面发挥着至关重要的作用。在植物中，已根据活性位点基序鉴定了三种不同的 GRX 类别。 CPYC 和 CGFS 类存在于所有生物体中，而 CC 类是高等陆地植物特有的。最近，两种拟南芥CC型GRX，ROXY1和ROXY2，被证明在花瓣和花药的起始和分化中发挥关键功能。为了分析CC型GRX在远缘单子叶植物中的功能，我们分离并表征了OsROXY1和OsROXY2——ROXY1的两个水稻同源物。这两种基因都在营养和生殖阶段表达。尽管水稻花形态与真双子叶植物不同，但 OsROXY1/2 花表达模式与拟南芥对应物 ROXY1/2 相似。互补实验表明OsROXY1和OsROXY2可以完全挽救roxy1花突变体表型。 OsROXY1、OsROXY2 和 ROXY1 在拟南芥中的过度表达会导致类似的营养和生殖植物发育缺陷。因此，ROXY1 及其水稻同源物在双子叶植物和单子叶植物花发育过程中发挥保守的功能。引人注目的是，这些 CC 型 GRX 的过度表达还会导致过氧化氢水平积累增加，并且对坏死营养型病原体灰葡萄孢 (Botrytis cinerea) 的感染高度敏感，揭示了平衡氧化还原过程在花器官发育和病原体防御中的重要性。
Glutaredoxins (GRXs) are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we isolated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxy1 floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Arabidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ development and pathogen defence.