Functional characterisation of OsCPK21, a calcium-dependent protein kinase that confers salt tolerance in rice.
Calcium acts as a messenger in various signal transduction pathways in plants. Calcium-dependent protein kinases (CDPKs) play important roles in regulating downstream components in calcium signaling pathways. In rice, the CDPKs constitute a large multigene family consisting of 29 genes, but the biological functions and functional divergence or redundancy of most of these genes remain unclear. Using a mini-scale full-length cDNA overexpressor (FOX) gene hunting system, we generated 250 independent transgenic rice plants overexpressing individual rice CDPKs (CDPK FOX-rice lines). These CDPK FOX-rice lines were screened for salt stress tolerance. The survival rate of the OsCPK21-FOX plants was higher than that of wild-type (WT) plants grown under high salinity conditions. The inhibition of seedling growth by abscisic acid (ABA) treatment was greater in the OsCPK21-FOX plants than in WT plants. Several ABA- and high salinity-inducible genes were more highly expressed in the OsCPK21-FOX plants than in WT plants. These results suggest that OsCPK21 is involved in the positive regulation of the signaling pathways that are involved in the response to ABA and salt stress.
Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan. tasano@affrc.go.jp
Takayuki
T
Asano
Makoto
M
Hakata
Hidemitsu
H
Nakamura
Naohiro
N
Aoki
Setsuko
S
Komatsu
Hiroaki
H
Ichikawa
Hirohiko
H
Hirochika
Ryu
R
Ohsugi
D000040:Abscisic Acid / Q000494:pharmacology; D003080:Cold Temperature; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055049:Salt Tolerance / Q000235:genetics* / Q000502:physiology; D055051:Salt-Tolerant Plants / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases
D000040:Abscisic Acid; D010940:Plant Proteins; D011494:Protein Kinases; D012965:Sodium Chloride; C454865:calcium-dependent protein kinase, rice; D017871:Calcium-Calmodulin-Dependent Protein Kinases