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 which are characterized with the definite types of juvenile, rosette, folding and head leaves. From shoot tips of Chinese cabbage at early folding stage, we constructed a cDNA library and screened the differentially expressed cDNA clones using the cDNAs derived from developing folding leaves and rosette leaves as probes. One complete length of cDNA clone is designated asBcpLH. Computer alignment matched BcpLH to the domains of double-stranded RNA binding (DBRM) and the homologous regions were recognized between BcpLH and human and mouse double-stranded RNA-binding protein TRBP. PCR expression analysis shows that during vegetative growthBcpLH gene was expressed preferentially in folding leaves at folding stage. Transcripts ofBcpLH gene were increased when plants were sprayed with IAA. It is deduced thatBcpLH gene may be related to initiation of folding leaf and leafy head and induced by auxin in the aspect of transcriptional expression.