Receptor-like kinase OsSIK1 improves drought and salt stress tolerance in rice (Oryza sativa) plants.
Receptor-like kinases (RLKs) play essential roles in plant growth, development and responses to environmental stresses. A putative RLK gene, OsSIK1, with extracellular leucine-rich repeats was cloned and characterized in rice (Oryza sativa). OsSIK1 exhibits kinase activity in the presence of Mn(2+), and the OsSIK1 kinase domain has the ability to autophosphorylate and phosphorylate myelin basic protein (MBP). OsSIK1 promoter-GUS analysis revealed that OsSIK1 is expressed mainly in the stem and spikelet in rice. The expression of OsSIK1 is mainly induced by salt, drought and H(2)O(2) treatments. Transgenic rice plants with overexpression of OsSIK1 show higher tolerance to salt and drought stresses than control plants. On the contrary, the knock-out mutants sik1-1 and sik1-2, as well as RNA interference (RNAi) plants, are sensitive to drought and salt stresses. The activities of peroxidase, superoxide dismutase and catalase are enhanced significantly in OsSIK1-overexpressing plants. Also, the accumulation of H(2)O(2) in leaves of OsSIK1-overexpressing plants is much less than that of the mutants, RNAi plants and control plants, as measured by 3,3'-diamino benzidine (DAB) staining. We also show that OsSIK1 affects stomatal density in the abaxial and adaxial leaf epidermis of rice. These results indicate that OsSIK1 plays important roles in salt and drought stress tolerance in rice, through the activation of the antioxidative system.
Ouyang
Shou-Qiang
SQ
Plant Gene Research Center, National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Liu
Yun-Feng
YF
Liu
Peng
P
Lei
Gang
G
He
Si-Jie
SJ
Ma
Biao
B
Zhang
Wan-Ke
WK
Zhang
Jin-Song
JS
Chen
Shou-Yi
SY
D000595:Amino Acid Sequence; D002374:Catalase / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D006861:Hydrogen Peroxide / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D010544:Peroxidases / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D055051:Salt-Tolerant Plants / Q000201:enzymology / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism
D010940:Plant Proteins; D018749:RNA, Plant; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D010544:Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D010770:Phosphotransferases