Cloning and Expression Analysis of BnHSFA4a Gene in Brassica napus

A full-length sequence of BnHSFA4a was obtained from Brassica napus by RT-PCR and RACE for the first time,named BnHSFA4a(GenBank accession No.HQ435241).The full length of BnHSFA4a is 1 667 bp,encoding 389 amino acids.Homology analysis of amino acid sequence of BnHSFA4a showed 82% similarity with AtHSFA4a.Multi-alignments of 33 different kinds of HSFs showed high similarity more than 60% at 100 to 190 aa in their amino acid sequences.Prokaryotic expression showed the recombinant vector can express the prospective protein.The semi-quantitative RT-PCR indicated that the expression of BnHSFA4a was followed by the expression of BnGOLS1,which is in accord with hypothesis that BnHSFA4a regulates BnGOLS1.It suggests that BnHSFA4a may play an important role in the mechanisms of seed desiccation tolerance through regulating the expression of BnGOLS1.