Isolation and characterization of an ERF-B3 gene associated with flower abnormalities in non-heading Chinese cabbage

BrcERF-B3 gene, a member of ethylene-responsive factor family, was screened from a mutant plant in non-heading Chinese cabbage (Brassica rapa ssp. chinensis) by cDNA-AFLP technology. We got full length cDNA of two BrcERF-B3 genes by homology-based cloning from two materials and found that their nucleotide sequences were the same by sequencing. The BrcERF-B3 protein, belonging to the B3 subgroup of the ERF subfamily, shared a close relationship with B. rapa. RT-PCR result showed that BrcERF-B3 expressed only in mutant stamen rather than maintainer stamen. qRT-PCR results indicated that BrcERF-B3 expressed highly during reproductive growth development and in the early of mutant buds, suggesting BrcERF-B3 might be involved in the formation of abnormal flower in mutant. What's more, the expression of BrcERF-B3 was more significant to ABA, MeJA and cold stresses in mutant than in maintainer and was down-regulated in NaCl treatment in two lines, implying BrcERF-B3 might be different roles in biotic and abiotic stresses.