The R2R3-MYB transcription factor RmMYB27 of Rosa multiflora regulates RmCOR47 positively modulate cold tolerance.

Area of Science:

• Plant Biology
• Molecular Biology
• Genetics

Background:

• MYB transcription factors regulate plant growth, metabolism, and stress responses.
• The specific role of MYB TFs in plant cold tolerance remains largely unelucidated.
• Rosa multiflora, a cold-resistant plant, serves as a model for studying cold adaptation mechanisms.

Purpose of the Study:

• To identify and characterize a novel MYB transcription factor involved in cold tolerance in Rosa multiflora.
• To investigate the function of RmMYB27 in response to cold, abscisic acid (ABA), and dehydration stresses.
• To elucidate the molecular mechanism by which RmMYB27 confers cold tolerance.

Main Methods:

• RNA-sequence analysis to identify cold-responsive genes.
• Gene cloning, expression analysis, and subcellular localization of RmMYB27.
• Functional analysis using overexpression in tobacco and virus-induced gene silencing (VIGS) in wild rose.
• Biochemical assays to measure antioxidant enzyme activities and reactive oxygen species levels.
• Promoter binding assays and gene expression analysis of cold-regulated (COR) genes.

Main Results:

• RmMYB27, a cold-responsive R2R3-MYB TF, was identified and activated by ABA, cold, and dehydration.
• Overexpression of RmMYB27 enhanced cold tolerance in tobacco, while its silencing in wild rose increased cold sensitivity.
• RmMYB27 positively regulated antioxidant enzyme activities (POD, SOD) and reduced reactive oxygen species accumulation.
• RmMYB27 directly binds to and activates the promoter of the cold-regulated gene RmCOR47.

Conclusions:

• RmMYB27 plays a crucial positive role in enhancing plant cold tolerance.
• The mechanism involves the regulation of antioxidant defense systems and the expression of cold-responsive genes like RmCOR47.
• RmMYB27 is a key regulator of cold stress response in plants, offering potential for crop improvement.