The SR Splicing Factors: Providing Perspectives on Their Evolution, Expression, Alternative Splicing, and Function in...

Area of Science:

• Plant molecular biology
• Genomics and transcriptomics
• Plant stress physiology

Background:

• Serine/arginine-rich (SR) proteins are vital splicing factors in plant development and stress adaptation.
• Limited information exists regarding the role of SR proteins in woody plants.
• Understanding SR protein function in poplar (Populus trichocarpa) is crucial for improving stress tolerance.

Purpose of the Study:

• To identify and characterize the SR protein gene family in Populus trichocarpa.
• To investigate the evolutionary history, expression patterns, and functional roles of PtSR genes under various stress conditions.
• To elucidate the specific function of PtSCL30 in mediating responses to cold and salt stress.

Main Methods:

• Phylogenetic analysis and gene synteny to explore PtSR gene evolution.
• RNA sequencing (RNA-seq) to analyze gene expression and alternative splicing (AS).
• Transgenic experiments in Arabidopsis to assess the function of PtSCL30.

Main Results:

• Identified 24 PtSR genes in Populus trichocarpa, organized into six subfamilies, shaped by genome duplication events.
• PtSR genes are constitutively expressed in various tissues and most respond to abiotic and hormone-related stresses, particularly cold stress.
• Overexpression of PtSCL30 in Arabidopsis reduced freezing tolerance and increased salt hypersensitivity, suggesting a negative regulatory role.

Conclusions:

• The PtSR gene family plays a fundamental role in poplar growth and stress response.
• Cold stress significantly impacts PtSR gene expression and alternative splicing.
• PtSCL30 acts as a negative regulator of cold and salt stress tolerance in plants, potentially through modulating AS of key stress-related genes.