Rhythmic lipid and gene expression responses to chilling in panicoid grasses

Area of Science:

• Plant Biology
• Molecular Biology
• Stress Physiology

Background:

• Chilling stress disrupts plant growth by affecting membrane fluidity and cellular integrity.
• Understanding plant membrane responses to chilling is crucial for improving stress tolerance.
• Lipid changes in response to chilling stress vary significantly across plant species.

Purpose of the Study:

• To investigate gene expression and membrane lipid changes in response to chilling stress in chilling-tolerant foxtail millet and chilling-sensitive sorghum.
• To compare chilling stress responses across related grass species with differing tolerance levels.
• To identify conserved and distinct molecular mechanisms underlying chilling tolerance.

Main Methods:

• Comparative analysis of gene expression and membrane lipid profiles in foxtail millet, sorghum, and Urochloa under chilling stress.
• Investigated responses over a 24-hour cycle to capture temporal dynamics.
• Integrated lipidomics and transcriptomics data to identify candidate genes.

Main Results:

• Most chilling-induced lipid changes were conserved across the three grass species.
• Foxtail millet exhibited distinct, time-specific lipid responses, suggesting finely tuned adaptive mechanisms.
• Rhythmic patterns in lipid responses were observed across species, including Arabidopsis thaliana, emphasizing the importance of diurnal cycles.
• Candidate genes involved in chilling tolerance were identified by integrating lipid and gene expression data.

Conclusions:

• Chilling stress responses in plants involve both conserved and species-specific mechanisms, particularly in membrane lipid composition.
• Temporal dynamics and rhythmic patterns play a significant role in plant adaptation to chilling stress.
• The study provides insights into the genetic basis of chilling tolerance, differentiating sensitive and tolerant species.