Leaf Senescence Regulation Mechanism Based on Comparative Transcriptome Analysis in Foxtail Millet

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Leaf senescence is crucial for crop yield and quality.
• Foxtail millet (Setaria italica) is a valuable C4 model crop with limited research on senescence mechanisms.
• Identifying senescence-associated genes (SAGs) and regulatory pathways is essential.

Purpose of the Study:

• Investigate physiological and transcriptomic changes during dark-induced senescence (DIS) in foxtail millet.
• Compare senescence patterns between light senescence (LS) and severe senescence (SS) varieties.
• Identify novel SAGs involved in regulating leaf senescence.

Main Methods:

• Applied a dark-induced senescence (DIS) experimental system.
• Conducted physiological and biochemical analyses.
• Performed comparative transcriptome analysis and Weighted Gene Co-expression Network Analysis (WGCNA).
• Validated findings using RT-qPCR.

Main Results:

• LS variety showed delayed senescence; SS variety showed accelerated senescence.
• Significant differences in photosynthesis, chlorophyll, and lipid metabolism gene expression were observed.
• LS variety exhibited up-regulation in genes for polysaccharide/calcium binding, nitrogen utilization, defense, and malate metabolism.
• SS variety showed altered expression of genes related to redox homeostasis, carbohydrate/lipid metabolism, and hormone signaling.
• Identified three SAGs potentially negatively regulating DIS.

Conclusions:

• This study provides foundational insights into the molecular regulation of leaf senescence in foxtail millet.
• Identified potential genetic resources for manipulating senescence to improve crop traits.
• Highlights the differential gene expression patterns associated with varying senescence rates.