Identification and phylogenetic analysis of late embryogenesis abundant proteins family in tomato (Solanum lycopersicum)

This study provided a comparative genomic analysis of the LEA gene family, and these may provide valuable information for their functional investigations in the future. Late embryogenesis abundant (LEA) proteins are a group of proteins that accumulate in response to cellular dehydration in many organisms. Here, we identified 27 LEA genes in tomato. A strong correlation between phylogeny, gene structure, and motif composition was found. The predicted SlLEA genes were non-randomly distributed within their chromosomes, and segmental and tandem duplications were probably important for their expansion. Many cis-elements potentially mediating transcription in response to abiotic stress were also found in the 1,000 bp upstream sequence of the promoter region. An additional intragenic recombination played an important role in the evolution of SlLEA genes. Selection analysis also identified some significant site-specific constraints that acted on the evolution of most LEA paralogs. Expression analysis using both microarray data and quantitative real-time PCR indicated that SlLEA genes were widely expressed in various tissues, and that a few members responded to some abiotic stresses. Our study provides useful information on the LEA genes in tomato and will facilitate their further characterization to better understand their functions.