Co-expression of SpSOS1 and SpAHA1 in transgenic Arabidopsis plants improves salinity tolerance
Co-expression of SpSOS1 and SpAHA1 in transgenic Arabidopsis plants improves salinity tolerance
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SpSOS1和SpAHA1在转基因拟南芥植物中的共表达提高了耐盐性
DOI：
10.1186/s12870-019-1680-7
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发表时间：
2019-02-14
影响因子：
5.3
通讯作者：
Jiang, Xingyu
中科院分区：
文献类型：
--
作者：
Fan, Yafei;Yin, Xiaochang;Jiang, Xingyu
从细胞中挤出Na+对植物在高盐环境中的生长至关重要。SOS1（盐过度敏感1）是一种位于质膜（PM）上的Na+/H+反转运蛋白，其功能是利用PM定位的H+- atp酶（AHA）产生的电化学质子梯度能量从细胞中挤出有毒的Na+。因此，SOS1和AHA参与了植物对盐胁迫的适应。本研究将盐生植物Sesuvium portulacastrum的SOS1和AHA编码基因（分别为SpSOS1和SpAHA1）一起或单独导入拟南芥植株。结果表明，SpSOS1或SpAHA1均能使转基因植株具有耐盐性，并且正如预期的那样，同时表达SpSOS1和SpAHA1的拟南芥植株在盐胁迫下比只表达SpSOS1或SpAHA1的植株生长得更好。在NaCl处理下，经SpSOS1或SpAHA1转化的植株根系中Na+和H+的流出速度比野生型（WT）植株快。此外，与单一表达SpSOS1/SpAHA1的转基因植株相比，共表达SpSOS1和SpAHA1的根具有更高的Na+和H+外排速率，导致前者积累的Na+少于后者。从盐胁迫植株对比分析中可以看出，共转基因SpSOS1和SpAHA1植株丙二醛（MDA）含量最低，但K+含量最高。这些结果表明SpSOS1和SpAHA1通过提高Na+挤出效率来维持K+稳态，保护PM免受盐胁迫引起的氧化损伤，从而减轻盐毒性。
Na+ extrusion from cells is important for plant growth in high saline environments. SOS1 (salt overly sensitive 1), an Na+/H+ antiporter located in the plasma membrane (PM), functions in toxic Na+ extrusion from cells using energy from an electrochemical proton gradient produced by a PM-localized H+-ATPase (AHA). Therefore, SOS1 and AHA are involved in plant adaption to salt stress.In this study, the genes encoding SOS1 and AHA from the halophyte Sesuvium portulacastrum (SpSOS1 and SpAHA1, respectively) were introduced together or singly into Arabidopsis plants. The results indicated that either SpSOS1 or SpAHA1 conferred salt tolerance to transgenic plants and, as expected, Arabidopsis plants expressing both SpSOS1 and SpAHA1 grew better under salt stress than plants expressing only SpSOS1 or SpAHA1. In response to NaCl treatment, Na+ and H+ in the roots of plants transformed with SpSOS1 or SpAHA1 effluxed faster than wild-type (WT) plant roots. Furthermore, roots co-expressing SpSOS1 and SpAHA1 had higher Na+ and H+ efflux rates than single SpSOS1/SpAHA1-expressing transgenic plants, resulting in the former amassing less Na+ than the latter. As seen from comparative analyses of plants exposed to salinity stress, the malondialdehyde (MDA) content was lowest in the co-transgenic SpSOS1 and SpAHA1 plants, but the K+ level was the highest.These results suggest SpSOS1 and SpAHA1 coordinate to alleviate salt toxicity by increasing the efficiency of Na+ extrusion to maintain K+ homeostasis and protect the PM from oxidative damage induced by salt stress.