Increasing cyclic electron flow is related to Na+sequestration into vacuoles for salt tolerance in soybean
| Autor: | Xiao-Man Wang, Gang-Ping Xue, Andrew T. James, Yi He, Chenliang Yu, Dean Jiang, Qinsu Jiang, Ligen Xu, Cheng-Qi Yan, Jianping Chen, Jian Hong, Kaixing Lu, Junliang Fu |
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| Rok vydání: | 2015 |
| Předmět: |
Physiology
Sodium Antiporter chemistry.chemical_element Dehydrogenase NDH complex Plant Science Vacuole Biology Photosynthesis Electron Transport Adenosine Triphosphate Stress Physiological Na+ accumulation Chlorophyll fluorescence Plant Proteins CEF NADPH Dehydrogenase food and beverages Salt Tolerance ATP soybean Chloroplast Biochemistry chemistry Vacuoles Soybeans NAD+ kinase Mesophyll Cells Research Paper |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| Popis: | Highlight 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. |
| Databáze: | OpenAIRE |
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