ABSTRACT
Objective: To clone and characterize a late embryogenesis abundant protein SmLEA2 with its promoter region from Salvia miltiorrhiza, and to predict its probable function. Methods: SmLEA2 was cloned by PCR and RT-PCR from genomic DNA and cDNA. Protein structure and phylogenetic relationships were carried out by bioinformatic analysis. Gene expression in different organs and different development periods was detected by qPCR. Gene expression was also detected under different treatments. Results: By analyzing the cDNA library for S. miltiorrhiza with BLAST program, one of these sequences showed a high homology with late embryogenesis abundant (LEA) protein and was named as SmLEA2 (GenBank: HQ676610). We obtained 1 961 bp gene sequences of SmLEA2, which contained an intron and a single opening reading frame (ORF) of 960 bp encoding 319 amino acid peptides. Bioinformatic analysis showed that the putative SmLEA2 protein was a hydrophilic protein without signal peptides and transmembrane domains. The SmLEA2 protein was predicted with a molecular weight of 35 340 and a theoretical isoelectric point of 4.77. SmLEA2 was expressed in the roots, stems, and leaves of S. miltiorrhiza, and the most abundant in the stems. With the development of the flowers and seeds, its expression increased gradually. Expression of SmLEA2 could be induced by methyl jasmonate (MeJA) and abscisic acid (ABA). Conclusion: Thus, we speculate that SmLEA2 may be involved in seed development and plant defenses.