Genome-scale identification and analysis of LEA genes in rice (Oryza sativa L.)

LEA proteins are late embryonic proteins abundant in higher plant embryos. It has been found that LEA genes are a gene family and play important roles in the protection of water stress. In this study, we employed bioinformatics approaches to identify new members of LEA gene family in rice. A total of 34 rice LEA (OsLEA) genes were identified, of which 25 were new. Four OsLEA genes were found to have alternative splicing. The OsLEA genes are distributed on all rice chromosomes except for chromosomes 10 and 12. Two independent series of gene conversion events were observed. Microarray data and semiquantitative reverse transcription PCR analysis revealed that the expressions of OsLEA genes are very diverse, some are consititutive, some are regulated and some appear to be related to stress tolerance. Two conserved motifs CACGTA and CACGCACG were found to be overrepresented in the 1 kb upstream regions of the ABA-induced and drought-induced LEA genes.