A R2R3-type MYB gene, OsMYB2, is involved in salt, cold, and dehydration tolerance in rice.
MYB-type transcription factors play a diverse role in plant development and response to abiotic stress. This study isolated a rice R2R3-type MYB gene, OsMYB2, and functionally characterized its role in tolerance to abiotic stress by generating transgenic rice plants with overexpressing and RNA interference OsMYB2. Expression of OsMYB2 was up-regulated by salt, cold, and dehydration stress. OsMYB2 was localized in the nucleus with transactivation activity. No difference in growth and development between the OsMYB2-overexpressing and wild-type plants was observed under normal growth conditions, but the OsMYB2-overexpressing plants were more tolerant to salt, cold, and dehydration stresses and more sensitive to abscisic acid than wild-type plants. The OsMYB2-overexpressing plants accumulated greater amounts of soluble sugars and proline than wild-type plants under salt stress. Overexpression of OsMYB2 enhanced up-regulation of genes encoding proline synthase and transporters. The OsMYB2-overexpressing plants accumulated less amounts of H(2)O(2) and malondialdehyde. The enhanced activities of antioxidant enzymes, including peroxidase, superoxide dismutase, and catalase, may underlie the lower H(2)O(2) contents in OsMYB2-overexpressing plants. There was greater up-regulation of stress-related genes, including OsLEA3, OsRab16A, and OsDREB2A, in the OsMYB2-overexpressing plants. Microarray analysis showed that expression of numerous genes involving diverse functions in stress response was altered in the OsMYB2-overexpressing plants. These findings suggest that OsMYB2 encodes a stress-responsive MYB transcription factor that plays a regulatory role in tolerance of rice to salt, cold, and dehydration stress.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, PR China.
An
A
Yang
Xiaoyan
X
Dai
Wen-Hao
WH
Zhang
D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D010940:Plant Proteins; D014157:Transcription Factors; D014867:Water; D012965:Sodium Chloride