Genome-Wide Analysis of LEA Gene Family in Rosa chinensis ‘Old Blush’ and Cold-Induced Expression Patterns in Two Species

Late embryogenesis abundant (LEA) proteins play an essential role in plant growth under various abiotic stresses. In this study, we identified 23 RcLEA genes in Rosa chinensis ‘Old Blush’ and subsequently grouped them into eight clades according to phylogenetic relationships and conserved domain features by bioinformatics methods. And conserved protein motifs and gene structure are also analyzed. The cis-regulatory elements of RcLEA promoter are enriched with cis-regulatory elements relevant to abiotic stress adaptation. Comparative transcriptomics between two species revealed tissue-specific and cold-induced expression differences, highlighting distinct functional roles of LEA genes in growth and abiotic stress tolerance between Rosa chinensis ‘Old Blush’ and Rosa beggeriana. Furthermore, Quantitative Real-Time PCR (qRT-PCR validation confirmed divergent cold-responsive expression profiles of LEA genes in R. chinensis ‘Old Blush’ compared with the highly cold-tolerant R. beggeriana in four LEA homologous genes. These findings indicated that LEA acts as a cold-response gene in roses and provide foundation to breed cold-tolerant varieties of roses.