A calcium-dependent protein kinase is involved in plant hormone signal transduction in Arabidopsis.
A number of signal pathways have been found through which abundant calcium-stimulated protein kinase activity in plant is associated with calcium-dependent protein kinases (CDPKs) which act as the calcium sensors mediating numerous responses, including hormone signaling. Basing on previous studies, we made additional functional analysis of the gene AtCPK30 encoding a protein kinase in Arabidopsis. Results of semi-quantitative reverse transcription PCR (RT-PCR) analysis indicated that AtCPK30 was highly expressed in root and induced by ABA, IAA, 2,4-D, GA(3) and 6-BA treatment. The physiological roles of AtCPK30 were studied using a gain-of-function approach. Seedlings of AtCPK30 transgenic lines had longer primary roots than those plants of wild-type at the early stages. Interestingly, when these plants grew on MS lack of Ca(2+) including wild-type and transgenic lines, the roots of transgenic line were more sensitive to calcium, lack of Ca(2+) had less effect on roots of transgenic lines than those of wild-type. Treated with several plant hormones, such as ABA, IAA, GA(3) and 6-BA, the roots of seedlings of transgenic line developed abnormally because they were more sensitive to hormones. Furthermore, NPA relatively less inhibited emergency of lateral roots of transgenic line than those of the wild-type. Green fluorescent protein-CPK30 (GFP-CPK30) fusion protein studies revealed the localization of AtCPK30 to both cell wall and plasma membrane. These results suggest that AtCPK30 acts as the calcium sensor and involved in the hormone-signaling pathways.
Yuan
Xin
X
Bioenergy and Biomaterial Research Center, Institute of Life Science and Biotechnology, Hunan University, Changsha 410082, China.
Deng
Ke-Qin
KQ
Zhao
Xiao-Ying
XY
Wu
Xian-Jin
XJ
Qin
Yu-Zhi
YZ
Tang
Dong-Ying
DY
Liu
Xuan-Ming
XM
D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
D000040:Abscisic Acid; D029681:Arabidopsis Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D011494:Protein Kinases; C000622374:CPK30 protein, Arabidopsis