Increasing cyclic electron flow is related to Na+ sequestration into vacuoles for salt tolerance in soybean.
Increasing cyclic electron flow is related to Na+ sequestration into vacuoles for salt tolerance in soybean.
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循环电子流的增加与大豆耐盐性的钠封入液泡有关
DOI：
10.1093/jxb/erv392
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发表时间：
2015-11
影响因子：
6.9
通讯作者：
Jiang D
中科院分区：
文献类型：
--
作者：
He Y;Fu J;Yu C;Wang X;Jiang Q;Hong J;Lu K;Xue G;Yan C;James A;Xu L;Chen J;Jiang D
在盐胁迫下，循环电子流的增强促进了ATP的积累，通过Na+转运相关基因的上调，促进了Na+在叶肉细胞的液泡中固存。在陆地植物中，NAD(P)H脱氢酶（NDH）复合体可减少质体醌并驱动PSI周围的循环电子流（CEF）。它还为光合作用产生额外的ATP，提高植物在非生物环境胁迫条件下的适应性。为了阐明CEF在光合机构耐盐性中的作用，我们监测了Na+浓度、叶绿素荧光、NDH B和H亚基的表达以及细胞和液泡中Na+运输相关基因的表达。耐盐大豆品种S111-9在光照条件下CEF活性和ATP积累明显高于盐敏感品种Melrose，但在盐胁迫下叶片Na+浓度相近。在S111-9植株中，ndhB和ndhH在盐胁迫下被高度上调，相应的蛋白维持在较高水平或显著升高。盐胁迫下，S111-9植株液泡积累Na+，而Melrose植株叶绿体积累Na+。与Melrose相比，S111-9植株也表达了一些与Na+转运到液泡和/或细胞中的相关基因，如编码CBL10（钙调磷酸酶b样蛋白10）-CIPK24（钙调磷酸酶相互作用蛋白激酶24）-NHX （Na+/H+反转运蛋白）和CBL4（钙调磷酸酶b样蛋白4）-CIPK24 - sos1（盐过敏感1）复合物组分的基因。基于这些发现，我们提出增强的ndh依赖性CEF提供了额外的ATP，用于在液泡中隔离Na+。这揭示了大豆耐盐的重要机制，为植物抗盐胁迫提供了新的认识。
Enhanced cyclic electron flow contributes to increased accumulation of ATP in light, which facilitates Na+ sequestration into vacuoles of mesophyll cells mediated by up-regulation of genes associated with Na+ transport during salt stress. In land plants, the NAD(P)H dehydrogenase (NDH) complex reduces plastoquinones and drives cyclic electron flow (CEF) around PSI. It also produces extra ATP for photosynthesis and improves plant fitness under conditions of abiotic environmental stress. To elucidate the role of CEF in salt tolerance of the photosynthetic apparatus, Na+ concentration, chlorophyll fluorescence, and expression of NDH B and H subunits, as well as of genes related to cellular and vacuolar Na+ transport, were monitored. The salt-tolerant Glycine max (soybean) variety S111-9 exhibited much higher CEF activity and ATP accumulation in light than did the salt-sensitive variety Melrose, but similar leaf Na+ concentrations under salt stress. In S111-9 plants, ndhB and ndhH were highly up-regulated under salt stress and their corresponding proteins were maintained at high levels or increased significantly. Under salt stress, S111-9 plants accumulated Na+ in the vacuole, but Melrose plants accumulated Na+ in the chloroplast. Compared with Melrose, S111-9 plants also showed higher expression of some genes associated with Na+ transport into the vacuole and/or cell, such as genes encoding components of the CBL10 (calcineurin B-like protein 10)–CIPK24 (CBL-interacting protein kinase 24)–NHX (Na+/H+ antiporter) and CBL4 (calcineurin B-like protein 4)–CIPK24–SOS1 (salt overly sensitive 1) complexes. Based on the findings, it is proposed that enhanced NDH-dependent CEF supplies extra ATP used to sequester Na+ in the vacuole. This reveals an important mechanism for salt tolerance in soybean and provides new insights into plant resistance to salt stress.