AtCPK6, a functionally redundant and positive regulator involved in salt/drought stress tolerance in Arabidopsis
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The calcium-dependent protein kinase (CDPK) family is needed in plant signaling during various physiological pathways. The Arabidopsis AtCPK6 gene belongs to the subclass of stress-inducible CDPKs, which is stimulated by salt and osmotic stress. To elucidate the physiological function of AtCPK6, transgenic Arabidopsis plants under the control of double CaMV 35S promoter were obtained. AtCPK6 over-expressing plants showed enhanced tolerance to salt/drought stresses. The elevated tolerance of the AtCPK6 over-expressing plants was confirmed by the change of proline and malondialdehyde (MDA). Real-time PCR analyses revealed that the expression levels of several stress-regulated genes were altered in AtCPK6 over-expressing plants. However, cpk6 mutant displayed no obvious difference with control. These results are likely to indicate that AtCPK6 is functionally redundant and a positive regulator involved in the tolerance to salt/drought stress in Arabidopsis.
KeywordsArabidopsis Drought Functionally redundant Salt Stress tolerance
Calcium-dependent protein kinase
Reactive oxygen species
We thank Prof. Julian I. Schroeder (University of California at San Diego, USA) for providing the seeds of loss-of-function mutant cpk6-1. This research was supported by Shanghai and National Natural Science Foundation (30670179, 08ZR1417200); 863 Program (2006AA10Z117, 2006AA06Z358, 2008AA10Z401); Shanghai Project for ISTC (08540706500); The Key Project Fund of the Shanghai Municipal Committee of Agriculture (No. 2008-7-5) and Shanghai Rising-Star Program (08QH14021).
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