Cloning and structural and expressional characterization of BcpLH gene preferentially expressed in folding leaf of Chinese cabbage

Vegetative growth of Chinese cabbage undergoes the four successive stages w hich are characterized with the definite types of juvenile, rosette, foldin g and head leaves. From shoot tips of Chinese cabbage at early folding stag e, we constructed a cDNA library and screened the differentially expressed cDNA clones using the cDNAs derived from developing folding leaves and rose tte leaves as probes. One complete length of cDNA clone is designated as Bc pLH. Computer alignment matched BcpLH to the domains of double-stranded RNA binding (DBRM) and the homologous regions were recognized between BcpLH an d human and mouse double-stranded RNA-binding protein TRBP. PCR expression analysis shows that during vegetative growth BcpLH gene was expressed prefe rentially in folding leaves at folding stage. Transcripts of BcpLH gene wer e increased when plants were sprayed with IAA. it is deduced that BcpLH gen e may be related to initiation of folding leaf and leafy head and induced b y auxin in the aspect of transcriptional expression.