Overproduction of the Membrane-bound Receptor-like Protein Kinase 1, RPK1, Enhances Abiotic Stress Tolerance in Arabidopsis
Overproduction of the Membrane-bound Receptor-like Protein Kinase 1, RPK1, Enhances Abiotic Stress Tolerance in Arabidopsis
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DOI：
10.1074/jbc.m109.051938
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发表时间：
2010-03-19
影响因子：
4.8
通讯作者：
Yamaguchi-Shinozaki, Kazuko
中科院分区：
文献类型：
--
作者：
Osakabe, Yuriko;Mizuno, Shinji;Yamaguchi-Shinozaki, Kazuko
RPK 1（receptor-like protein kinase 1，受体样蛋白激酶1）定位于拟南芥细胞质膜，是脱落酸（abscisic acid，阿坝）信号转导的调节因子。在我们目前的研究中，我们研究了RPK 1中断和过量生产对植物响应干旱胁迫的影响。过表达RPK 1蛋白的转基因拟南芥表现出对阿坝的敏感性增加，根系生长和气孔关闭也表现出较少的蒸腾失水。与此相反，一个突变体缺乏RPK 1功能，rpk 1 -1，被发现是抗阿坝在这些过程中，表现出增加的水分流失。因此，这些转基因植物中RPK 1的过量表达增加了它们对干旱胁迫的耐受性。我们对RPK 1转基因植物进行了微阵列分析，观察到除了H2 O2响应基因外，几个应激响应基因（如Cor 15 a，Cor 15 b和rd 29 A）的表达增强。与野生型相比，rpk 1 -1中阿坝/胁迫响应基因的表达量有所下降。结果表明，RPK 1的过量产生增强阿坝和干旱胁迫信号通路。此外，叶片的rpk 1 -1植物表现出更高的敏感性，ABA预处理后的氧化胁迫，而过量生产RPK 1的转基因植物表现出这种压力的耐受性增加。因此，我们目前的数据表明，RPK 1的过量生产控制活性氧的体内平衡，提高水和氧化胁迫的耐受性在拟南芥。
RPK1 (receptor-like protein kinase 1) localizes to the plasma membrane and functions as a regulator of abscisic acid (ABA) signaling in Arabidopsis. In our current study, we investigated the effect of RPK1 disruption and overproduction upon plant responses to drought stress. Transgenic Arabidopsis overexpressing the RPK1 protein showed increased ABA sensitivity in their root growth and stomatal closure and also displayed less transpirational water loss. In contrast, a mutant lacking RPK1 function, rpk1-1, was found to be resistant to ABA during these processes and showed increased water loss. RPK1 overproduction in these transgenic plants thus increased their tolerance to drought stress. We performed microarray analysis of RPK1 transgenic plants and observed enhanced expression of several stress-responsive genes, such as Cor15a, Cor15b, and rd29A, in addition to H2O2-responsive genes. Consistently, the expression levels of ABA/stress-responsive genes in rpk1-1 had decreased compared with wild type. The results suggest that the overproduction of RPK1 enhances both the ABA and drought stress signaling pathways. Furthermore, the leaves of the rpk1-1 plants exhibit higher sensitivity to oxidative stress upon ABA-pretreatment, whereas transgenic plants overproducing RPK1 manifest increased tolerance to this stress. Our current data suggest therefore that RPK1 overproduction controls reactive oxygen species homeostasis and enhances both water and oxidative stress tolerance in Arabidopsis.