A R2R3-type MYB gene,OsMYB2, is involved in salt, cold, and dehydration tolerance in rice

• Published in: Journal of experimental botany 2012-04, Vol.63 (7), p.2541-2556
• Main Authors: Yang, An, Dai, Xiaoyan, Zhang, Wen-Hao
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cold Temperature; Dehydration; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genes; Oryza - genetics; Oryza - physiology; Oryza sativa; Oxidative stress; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; RESEARCH PAPER; Research Papers; Rice; Salt tolerance; Salts; Seedlings; Sodium Chloride - metabolism; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transgenic plants; Water - metabolism
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/err431

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 interferenceOsMYB2. Expression ofOsMYB2was up-regulated by salt, cold, and dehydration stress. OsMYB2 was localized in the nucleus with transactivation activity. No difference in growth and development between theOsMYB2-overexpressing and wild-type plants was observed under normal growth conditions, but theOsMYB2-overexpressing plants were more tolerant to salt, cold, and dehydration stresses and more sensitive to abscisic acid than wild-type plants. TheOsMYB2-overexpressing plants accumulated greater amounts of soluble sugars and proline than wild-type plants under salt stress. Overexpression ofOsMYB2enhanced up-regulation of genes encoding proline synthase and transporters. TheOsMYB2-overexpressing plants accumulated less amounts of H₂O₂ and malondialdehyde. The enhanced activities of antioxidant enzymes, including peroxidase, superoxide dismutase, and catalase, may underlie the lower H₂O₂ contents inOsMYB2-overexpressing plants. There was greater up-regulation of stress-related genes, includingOsLEA3,OsRab16A, andOsDREB2A, in theOsMYB2-overexpressing plants. Microarray analysis showed that expression of numerous genes involving diverse functions in stress response was altered in theOsMYB2-overexpressing plants. These findings suggest thatOsMYB2encodes a stress-responsive MYB transcription factor that plays a regulatory role in tolerance of rice to salt, cold, and dehydration stress.