Molecular cloning, characterization and expression of a novel jasmonate-dependent defensin gene from Ginkgo biloba.
A novel defensin gene was isolated from Ginkgo biloba. The full-length cDNA of G. biloba defensin (designated as Gbd) was 534bp. The cDNA contained a 240-bp open reading frame encoding an 80-amino acid protein of 5.68 kDa with a potential 30 aa signal peptide. The putative GbD mature protein showed striking similarity to other plant defensins, representing low molecular size antimicrobial polypeptides. Eight cysteine sites conserved in plant defensins were also found in GbD at similar positions. Three-dimensional structure modeling showed that GbD strongly resembled defensin from tobacco (NaD1) and consisted of an alpha-helix and a triple-strand antiparallel beta-sheet that were stabilized by four intramolecular disulfide bonds, implying GbD may have functions similar to NaD1. The genomic DNA gel blot indicated that Gbd belonged to a multigene family. Expression analysis revealed that Gbd was up-regulated by wounding and methyl jasmonate treatments, suggesting that Gbd is potentially involved in plant resistance or tolerance to pathogens during wounding.
Shen
Guoan
G
Plant Biotechnology Research Center, School of Agriculture and Biology, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, SJTU-SIBS-PSU Joint Center for Life Sciences, Shanghai Jiao Tong University, PR China.
Pang
Yongzhen
Y
Wu
Weisheng
W
Miao
Zhiqi
Z
Qian
Hongmei
H
Zhao
Lingxia
L
Sun
Xiaofen
X
Tang
Kexuan
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology*; D017931:DNA Primers; D018076:DNA, Complementary; D023082:Defensins / Q000235:genetics*; D019143:Evolution, Molecular; D020441:Ginkgo biloba / Q000235:genetics*; D008969:Molecular Sequence Data; D054883:Oxylipins; D012333:RNA, Messenger / Q000235:genetics
D003517:Cyclopentanes; D017931:DNA Primers; D018076:DNA, Complementary; D023082:Defensins; D054883:Oxylipins; D012333:RNA, Messenger; C011006:jasmonic acid