Isolation and Expression Analysis of a GDSL-like Lipase Gene from Brassica napus L.

Abstract
As lipolytic enzymes, GDSL lipases play an important role in plant growth and development. In order to identify their functions and roles, the full-length cDNA of a GDSL lipase gene, designated BnLIP2, was isolated from Brassica napus L. BnLIP2 was 1,300 bp long, with 1,122 bp open reading frame (ORF) encoding 373 amino acid residues. Sequence analysis indicated that BnLIP2 belonged to GDSL family. Southern blot analysis indicated that BnLIP2 belonged to a small gene family in rapeseed genome. RT-PCR analysis revealed that BnLIP2 was a tissue-specific expressing gene during reproductive growth and strongly expressed during seed germination. BnLIP2 expression could not be detected until three days after germination, and it subsequently became stronger. The transcript of this gene was deficient in root of seedlings growing at different stages. When juvenile seedlings were treated by methyl jasmonate (MeJ), salicylic acid (SA) and naphthalene acetic acid (NAA), BnLIP2 expression could not be induced in root. Our study implicates that BnLIP2 probably plays an important role in rapeseed germination, morphogenesis, flowering, but independent of root growth and development.