Overexpression of an R1R2R3 MYB Gene, OsMYB3R-2, Increases Tolerance to Freezing, Drought, and Salt Stress in Transgenic Arabidopsis

Abstract

We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under cold stress and identified 328 cold-regulated genes. Thirteen such genes encoding MYB, homeodomain, and zinc finger proteins with unknown functions showed a significant change in expression under 72-h cold stress. Among them, OsMYB3R-2 was selected for further study. Unlike most plant R2R3 MYB transcription factors, OsMYB3R-2 has three imperfect repeats in the DNA-binding domain, the same as in animal c-MYB proteins. Expression of OsMYB3R-2 was induced by cold, drought, and salt stress. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing OsMYB3R-2 showed increased tolerance to cold, drought, and salt stress, and the seed germination of transgenic plants was more tolerant to abscisic acid or NaCl than that of wild type. The expression of some clod-related genes, such as dehydration-responsive element-binding protein 2A, COR15a, and RCI2A, was increased to a higher level in OsMYB3R-2-overexpressing plants than in wild type. These results suggest that OsMYB3R-2 acts as a master switch in stress tolerance.

Role of Plant Transcription Factors in Abiotic Stress Tolerance

“…AtMyb41 from Arabidopsis is transcriptionally regulated in response to salinity, drought, cold, and ABA (Lippold et al, 2009 (Gigolashvili et al, 2007). In contrast, OsMYB3R-2 transgenic plants showed enhanced tolerance to freezing, drought and salt stress and decreased sensitivity to ABA (Dai et al, 2007). Different level of tolerance was imparted by overexpression of OsMYB4 depending on the nature of the host plants.…”

MYB transcription factor genes as regulators for plant responses: an overview

“…OsMYB3R-2 in rice transgenic plants enhanced tolerance to freezing, dehydration and salt stress and decreased sensitivity to ABA (Dai et al 2007). Similarly, El-kereamy et al (2012) studied the rice R2R3-MYB transcription factor OsMYB55 and concluded that overexpression of OsMYB55 improved rice plant tolerance to high temperature which was associated with enhanced amino acid metabolism through transcription activation.…”

A Plasma Membrane-Anchored Fluorescent Protein Fusion Illuminates Sieve Element Plasma Membranes in Arabidopsis and Tobacco

“…The evidence for two transmembrane domains in the RCI2 protein family is still circumstantial (Nylander et al, 2001;Kroemer et al, 2004). response signaling (Nylander et al, 2001;Kroemer et al, 2004;Medina et al, 2005;Mitsuya et al, 2006;Dai et al, 2007). The gene possesses orthologs in a variety of plant species as well as three Pseudomonas species, Neurospora crassa, and Caenorhabditis elegans (Kroemer et al, 2004).…”