title: A rice calcium-dependent protein kinase OsCPK12 oppositely modulates salt-stress tolerance and blast disease resistance.
abstract: Calcium-dependent protein kinases (CDPKs) regulate the downstream components in calcium signaling pathways. We investigated the effects of overexpression and disruption of an Oryza sativa (rice) CDPK (OsCPK12) on the plant's response to abiotic and biotic stresses. OsCPK12-overexpressing (OsCPK12-OX) plants exhibited increased tolerance to salt stress. The accumulation of hydrogen peroxide (H(2) O(2) ) in the leaves was less in OsCPK12-OX plants than in wild-type (WT) plants. Genes encoding reactive oxygen species (ROS) scavenging enzymes (OsAPx2 and OsAPx8) were more highly expressed in OsCPK12-OX plants than in WT plants, whereas the expression of the NADPH oxidase gene, OsrbohI, was decreased in OsCPK12-OX plants compared with WT plants. Conversely, a retrotransposon (Tos17) insertion mutant, oscpk12, and plants transformed with an OsCPK12 RNA interference (RNAi) construct were more sensitive to high salinity than were WT plants. The level of H(2) O(2)  accumulation was greater in oscpk12 and OsCPK12 RNAi plants than in the WT. These results suggest that OsCPK12 promotes tolerance to salt stress by reducing the accumulation of ROS. We also observed that OsCPK12-OX seedlings had increased sensitivity to abscisic acid (ABA) and increased susceptibility to blast fungus, probably resulting from the repression of ROS production and/or the involvement of OsCPK12 in the ABA signaling pathway. Collectively, our results suggest that OsCPK12 functions in multiple signaling pathways, positively regulating salt tolerance and negatively modulating blast resistance.
authors: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan. tasano@affrc.go.jp
authors: Takayuki
authors: T
authors: Asano
authors: Nagao
authors: N
authors: Hayashi
authors: Michie
authors: M
authors: Kobayashi
authors: Naohiro
authors: N
authors: Aoki
authors: Akio
authors: A
authors: Miyao
authors: Ichiro
authors: I
authors: Mitsuhara
authors: Hiroaki
authors: H
authors: Ichikawa
authors: Setsuko
authors: S
authors: Komatsu
authors: Hirohiko
authors: H
authors: Hirochika
authors: Shoshi
authors: S
authors: Kikuchi
authors: Ryu
authors: R
authors: Ohsugi
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D060387:Ascorbate Peroxidases / Q000235:genetics; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D060467:Disease Resistance; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D020082:Magnaporthe / Q000472:pathogenicity*; D009154:Mutation; D019255:NADPH Oxidases / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D019255:NADPH Oxidases; D017871:Calcium-Calmodulin-Dependent Protein Kinases