Knockout of AtMKK1 enhances salt tolerance and modifies metabolic activities in Arabidopsis |
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| Authors: | Chad Conroy Jacqueline Ching Yan Gao Xiaojing Wang Christof Rampitsch Tim Xing |
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| Institution: | 1.Department of Biology and Institute of Biochemistry; Carleton University; Ottawa, ON Canada;2.Agriculture and Agri-Food Canada; Cereal Research Centre; Winnipeg, MB Canada;3.College of Life Sciences; South China Normal University; Guangdong Key Laboratory of Biotechnology for Plant Development; Guangzhou, P.R. China |
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| Abstract: | Mitogen-activated protein kinase (MAPK) pathways represent a crucial regulatory mechanism in plant development. The ability to activate and inactivate MAPK pathways rapidly in response to changing conditions helps plants to adapt to a changing environment. AtMKK1 is a stress response kinase that is capable of activating the MAPK proteins AtMPK3, AtMPK4 and AtMPK6. To elucidate its mode of action further, several tests were undertaken to examine the response of AtMKK1 to salt stress using a knockout (KO) mutant of AtMKK1. We found that AtMKK1 mutant plants tolerated elevated levels of salt during both germination and adulthood. Proteomic analysis indicated that the level of the α subunit of mitochrondrial H+-ATPase, mitochrondial NADH dehydrogenase and mitochrondrial formate dehydrogenase was enhanced in AtMKK1 knockout mutants upon high salinity stress. The level of formate dehydrogenase was further confirmed by immunoblotting and enzyme assay. The possible involvement of these enzymes in salt tolerance is discussed. |
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| Keywords: | AtMKK1 knockout mutant salt tolerance formate dehydrogenase proteomic analysis Arabidopsis |
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