The PLA Gene Family in Tomato: Identification, Phylogeny, and Functional Characterization

Area of Science:

• Plant molecular biology
• Genomics
• Biochemistry

Background:

• Phospholipase A (PLA) enzymes are crucial for plant growth, development, and stress responses.
• They catalyze glycerophospholipid hydrolysis, yielding bioactive fatty acids and lysophospholipids.

Purpose of the Study:

• To systematically identify and characterize the Phospholipase A (PLA) gene family in tomato (Solanum lycopersicum).
• To investigate the function of specific PLA genes, particularly SlPLA1-2, under cold stress conditions.

Main Methods:

• Bioinformatic analysis of the tomato genome to identify SlPLA genes.
• Phylogenetic analysis to categorize SlPLA genes into pPLA, PLA1, and PLA2 groups.
• Virus-induced gene silencing (VIGS) to study gene function under cold stress.
• RNA sequencing (RNA-seq) and quantitative real-time PCR (qRT-PCR) for gene expression analysis.
• Physiological assays to assess membrane damage and electrolyte leakage.

Main Results:

• Identified 80 SlPLA genes distributed across 12 tomato chromosomes.
• Phylogenetic and structural analyses revealed gene diversification and conserved motifs.
• SlPLA genes are regulated by light, hormones, and stress, with notable cold-stress responsiveness.
• The SlPLA1-2 gene was significantly upregulated under cold stress.
• Silencing SlPLA1-2 impaired cold tolerance, increasing membrane damage and reducing cold-responsive gene expression.

Conclusions:

• The study identified and classified 80 SlPLA genes in tomato.
• SlPLA1-2 plays a significant role in enhancing tomato cold tolerance.
• SlPLA1-2 functions by modulating the CBF signaling pathway and jasmonic acid biosynthesis.
• Findings provide insights for developing stress-resilient tomato varieties.