Overexpression of phosphatidylserine synthase IbPSS1 affords cellular Na+ homeostasis and salt tolerance by activating plasma membrane Na+/H+ antiport activity in sweet potato roots
Overexpression of phosphatidylserine synthase IbPSS1 affords cellular Na+ homeostasis and salt tolerance by activating plasma membrane Na+/H+ antiport activity in sweet potato roots
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磷脂酰丝氨酸合酶 IbPSS1 的过表达通过激活甘薯根质膜 Na /H 逆向转运活性提供细胞 Na 稳态和耐盐性
DOI：
10.1038/s41438-020-00358-1
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发表时间：
2020-08-01
影响因子：
8.7
通讯作者：
Sun, Jian
中科院分区：
文献类型：
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作者：
Yu, Yicheng;Xuan, Ying;Sun, Jian
磷脂酰丝氨酸合酶（PSS）介导的磷脂酰丝氨酸（PS）合成对于植物发育至关重要。然而，人们对 PSS 对植物 Na+ 稳态调节和耐盐性的贡献知之甚少。在这里，我们克隆了来自甘薯（Ipomoea batatas (L.) Lam.）的 IbPSS1 基因，该基因编码拟南芥 AtPSS1 的直向同源物。 IbPSS1 在本塞姆氏烟草叶片中的瞬时表达增加了 PS 丰度。然后，我们建立了一种有效的发根农杆菌介导的甘薯体内根转基因系统。与不定根相比，通过该系统过度表达 IbPSS1 显着降低了盐化转基因根 (TR) 中细胞 Na+ 的积累。 IbPSS1 的过表达增强了盐诱导的 Na+/H+ 反向转运活性，并增加了 TR 中质膜 (PM) Ca 2+ 渗透通道对 NaCl 和 H 2 O 2 的敏感性。我们证实了 IbPSS1 在提高从根癌农杆菌介导的转化系统获得的转基因甘薯品系的耐盐性方面的重要作用。类似地，与野生型(WT)植物相比，转基因株系表现出根部Na+积累减少、Na+排除增强以及PM Ca 2+ 渗透通道对NaCl和H 2 O 2 的敏感性增加。外源施用溶血磷脂酰丝氨酸引发了WT 盐化根中Na+ 积累以及Na+ 和Ca 2+ 通量的类似变化。总体而言，本研究为甘薯功能基因组研究提供了一种高效可靠的转基因方法。我们的结果表明，IbPSS1 通过在根部实现 Na+ 稳态和 Na+ 排除来促进甘薯的耐盐性，而后者过程可能是通过 PS 增强根部 Ca 2+ 信号传导来控制的。
Phosphatidylserine synthase (PSS)-mediated phosphatidylserine (PS) synthesis is crucial for plant development. However, little is known about the contribution of PSS to Na+ homeostasis regulation and salt tolerance in plants. Here, we cloned the IbPSS1 gene, which encodes an ortholog of Arabidopsis AtPSS1, from sweet potato (Ipomoea batatas (L.) Lam.). The transient expression of IbPSS1 in Nicotiana benthamiana leaves increased PS abundance. We then established an efficient Agrobacterium rhizogenes-mediated in vivo root transgenic system for sweet potato. Overexpression of IbPSS1 through this system markedly decreased cellular Na+ accumulation in salinized transgenic roots (TRs) compared with adventitious roots. The overexpression of IbPSS1 enhanced salt-induced Na+/H+ antiport activity and increased plasma membrane (PM) Ca 2+-permeable channel sensitivity to NaCl and H 2 O 2 in the TRs. We confirmed the important role of IbPSS1 in improving salt tolerance in transgenic sweet potato lines obtained from an Agrobacterium tumefaciens-mediated transformation system. Similarly, compared with the wild-type (WT) plants, the transgenic lines presented decreased Na+ accumulation, enhanced Na+ exclusion, and increased PM Ca 2+-permeable channel sensitivity to NaCl and H 2 O 2 in the roots. Exogenous application of lysophosphatidylserine triggered similar shifts in Na+ accumulation and Na+ and Ca 2+ fluxes in the salinized roots of WT. Overall, this study provides an efficient and reliable transgenic method for functional genomic studies of sweet potato. Our results revealed that IbPSS1 contributes to the salt tolerance of sweet potato by enabling Na+ homeostasis and Na+ exclusion in the roots, and the latter process is possibly controlled by PS reinforcing Ca 2+ signaling in the roots.