Gα modulates salt-induced cellular senescence and cell division in rice and maize
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Biology
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Biology. Dept. of Pharmacology
The plant G-protein network, comprising Gα, Gβ, and Gγ core subunits, regulates development, senses sugar, and mediates biotic and abiotic stress responses. Here in this paper, we report G-protein signalling in the salt stress response using two crop models, rice and maize. Loss-of-function mutations in the corresponding genes encoding the Gα subunit attenuate growth inhibition and cellular senescence caused by sodium chloride (NaCl). Gα null mutations conferred reduced leaf senescence, chlorophyll degradation, and cytoplasm electrolyte leakage under NaCl stress. Sodium accumulated in both wild-type and Gα-mutant shoots to the same levels, suggesting that Gα signalling controls cell death in leaves rather than sodium exclusion in roots. Growth inhibition is probably initiated by osmotic change around root cells, because KCl and MgSO4 also suppressed seedling growth equally as well as NaCl. NaCl lowered rates of cell division and elongation in the wild-type leaf sheath to the level of the Gα-null mutants; however there was no NaCl-induced decrease in cell division in the Gα mutant, implying that the osmotic phase of salt stress suppresses cell proliferation through the inhibition of Gα-coupled signalling. These results reveal two distinct functions of Gα in NaCl stress in these grasses: attenuation of leaf senescence caused by sodium toxicity in leaves, and cell cycle regulation by osmotic/ionic stress.
- Research Organization:
- University of North Carolina, Chapel Hill, NC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Inst. of General Medical Sciences (NIGMS) (United States); National Science Foundation (NSF)
- Grant/Contract Number:
- FG02-05ER15671; R01GM065989; MCB-0718202
- OSTI ID:
- 1343067
- Journal Information:
- Journal of Experimental Botany, Vol. 65, Issue 22; ISSN 0022-0957
- Publisher:
- Oxford University PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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