Overexpression of the CC-type glutaredoxin, OsGRX6 affects hormone and nitrogen status in rice plants.
Overexpression of the CC-type glutaredoxin, OsGRX6 affects hormone and nitrogen status in rice plants.
复制标题
CC型谷胱甘肽的过表达，OSGRX6影响水稻植物中的激素和氮状况。
DOI：
10.3389/fpls.2015.00934
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发表时间：
2015
影响因子：
5.6
通讯作者：
Rothstein SJ
中科院分区：
文献类型：
--
作者：
El-Kereamy A;Bi YM;Mahmood K;Ranathunge K;Yaish MW;Nambara E;Rothstein SJ
谷氧还蛋白（GRX）是一种小的谷胱甘肽依赖性氧化还原酶，属于硫氧还蛋白（TRX）超家族，催化其底物蛋白的二硫键还原。植物GRX根据基序序列分为三个不同的组，即CPYC、CGFS和CC型蛋白。水稻CC型蛋白OsGRX 6是在筛选其表达取决于可用硝酸盐水平的基因期间鉴定的。OsGRX 6在水稻中的过量表达表现出半矮秆表型。OsGRX 6过表达基因的氮含量高于野生型，表明OsGRX 6在氮利用的稳态调节中起作用。与此一致，OsGRX 6过表达子与野生型植物相比显示出延迟的叶绿素降解和衰老。为了检查这些转基因品系的生长缺陷是否归因于受干扰的植物激素作用，测量植物激素水平。两种细胞分裂素（CKs），2-异戊烯基腺嘌呤和反式玉米素，和赤霉素A1（GA 1）的水平在这些线增加。我们还发现这些转基因株系对外源GA不太敏感，这表明GA 1的增加是反馈调节的结果。这些数据表明OsGRX 6影响水稻植株中的激素信号传导和氮状况。
Glutaredoxins (GRXs) are small glutathione dependent oxidoreductases that belong to the Thioredoxin (TRX) superfamily and catalyze the reduction of disulfide bonds of their substrate proteins. Plant GRXs include three different groups based on the motif sequence, namely CPYC, CGFS, and CC-type proteins. The rice CC-type proteins, OsGRX6 was identified during the screening for genes whose expression changes depending on the level of available nitrate. Overexpression of OsGRX6 in rice displayed a semi-dwarf phenotype. The OsGRX6 overexpressors contain a higher nitrogen content than the wild type, indicating that OsGRX6 plays a role in homeostatic regulation of nitrogen use. Consistent with this, OsGRX6 overexpressors displayed delayed chlorophyll degradation and senescence compared to the wild type plants. To examine if the growth defect of these transgenic lines attribute to disturbed plant hormone actions, plant hormone levels were measured. The levels of two cytokinins (CKs), 2-isopentenyladenine and trans-zeatin, and gibberellin A1 (GA1) were increased in these lines. We also found that these transgenic lines were less sensitive to exogenously applied GA, suggesting that the increase in GA1 is a result of the feedback regulation. These data suggest that OsGRX6 affects hormone signaling and nitrogen status in rice plants.