Overexpression of a Calcium-Dependent Protein Kinase Confers Salt and Drought Tolerance in Rice by Preventing Membrane Lipid Peroxidation
Overexpression of a Calcium-Dependent Protein Kinase Confers Salt and Drought Tolerance in Rice by Preventing Membrane Lipid Peroxidation
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DOI：
10.1104/pp.113.230268
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发表时间：
2014-06-01
期刊：
影响因子：
7.4
通讯作者：
San Segundo, Blanca
中科院分区：
文献类型：
--
作者：
Campo, Sonia;Baldrich, Patricia;San Segundo, Blanca
OsCPK4基因是水稻（Oryza sativa）钙依赖性蛋白激酶复杂基因家族的成员。在这里，我们报道了OsCPK4的表达是由高盐度、干旱和植物激素脱落酸诱导的。此外，通过绿色荧光蛋白标记的OsCPK4在洋葱（Allium cepa）表皮细胞中的瞬时表达实验，观察到OsCPK4在质膜上的定位。OsCPK4在水稻中过表达可显著增强对盐胁迫和干旱胁迫的耐受性。然而，转基因水稻的生长发育受到严重损害。与对照植物相比，OsCPK4过表达植物在干旱或盐胁迫条件下表现出更强的持水能力，膜脂过氧化和电解质泄漏水平降低。此外，盐处理过的OsCPK4幼苗在根系中积累的Na+也较少。我们对过表达OsCPK4的转基因水稻进行了微阵列分析，发现过表达OsCPK4对水稻转录组的影响较小。此外，在水稻根系和叶片中未发现受OsCPK4共同调控的基因。在过表达者植物的根中，大量参与脂质代谢和氧化应激保护的基因似乎被OsCPK4上调。同时，OsCPK4过表达对表征良好的非生物胁迫相关转录调控网络（即ORYZA SATIVA dehydra - responsive ELEMENT BINDING protein - 1和ORYZA SATIVA no Apical merisystem、拟南芥转录激活因子1-2、杯形子叶6基因）以及根内胚发生晚期基因的表达没有影响。综上所述，我们的数据表明，OsCPK4通过保护细胞膜免受应激诱导的氧化损伤，在水稻盐胁迫和干旱胁迫反应中发挥着积极的调节作用。
The OsCPK4 gene is a member of the complex gene family of calcium-dependent protein kinases in rice (Oryza sativa). Here, we report that OsCPK4 expression is induced by high salinity, drought, and the phytohormone abscisic acid. Moreover, a plasma membrane localization of OsCPK4 was observed by transient expression assays of green fluorescent protein-tagged OsCPK4 in onion (Allium cepa) epidermal cells. Overexpression of OsCPK4 in rice plants significantly enhances tolerance to salt and drought stress. Knockdown rice plants, however, are severely impaired in growth and development. Compared with control plants, OsCPK4 overexpressor plants exhibit stronger water-holding capability and reduced levels of membrane lipid peroxidation and electrolyte leakage under drought or salt stress conditions. Also, salt-treated OsCPK4 seedlings accumulate less Na+ in their roots. We carried out microarray analysis of transgenic rice overexpressing OsCPK4 and found that overexpression of OsCPK4 has a low impact on the rice transcriptome. Moreover, no genes were found to be commonly regulated by OsCPK4 in roots and leaves of rice plants. A significant number of genes involved in lipid metabolism and protection against oxidative stress appear to be up-regulated by OsCPK4 in roots of overexpressor plants. Meanwhile, OsCPK4 overexpression has no effect on the expression of well-characterized abiotic stress-associated transcriptional regulatory networks (i.e. ORYZA SATIVA DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN1 and ORYZA SATIVA No Apical Meristem, Arabidopsis Transcription Activation Factor1-2, Cup-Shaped Cotyledon6 genes) and LATE EMBRYOGENESIS ABUNDANT genes in their roots. Taken together, our data show that OsCPK4 functions as a positive regulator of the salt and drought stress responses in rice via the protection of cellular membranes from stress-induced oxidative damage.