Characterization of the Sesbania rostrata phytochelatin synthase gene: alternative splicing and function of four isoforms.
Phytochelatins (PCs) play an important role in detoxification of heavy metals in plants. PCs are synthesized from glutathione by phytochelatin synthase (PCS), a dipeptidyltransferase. Sesbania rostrata is a tropical legume plant that can tolerate high concentrations of Cd and Zn. In this study, the S. rostrata PCS gene (SrPCS) and cDNAs were isolated and characterized. Southern blot and sequence analysis revealed that a single copy of the SrPCS gene occurs in the S. rostrata genome, and produces four different SrPCS mRNAs and proteins, SrPCS1-SrPCS4, by alternative splicing of the SrPCS pre-mRNA. The SrPCS1 and SrPCS3 proteins conferred Cd tolerance when expressed in yeast cells, whereas the SrPCS2 and SrPCS4 proteins, which lack the catalytic triad and the N-terminal domains, did not. These results suggested that SrPCS1 and SrPCS3 have potential applications in genetic engineering of plants for enhancing heavy metal tolerance and phytoremediation of contaminated soils.
Li
An-Ming
AM
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Yu
Bing-Yun
BY
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Chen
Fu-Hua
FH
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Gan
Hui-Yan
HY
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Yuan
Jian-Gang
JG
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Qiu
Rongliang
R
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Huang
Jun-Chao
JC
School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Yang
Zhong-Yi
ZY
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Xu
Zeng-Fu
ZF
State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.|Laboratory of Molecular Breeding of Energy Plants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, Yunnan, China.
D017398:Alternative Splicing; D019881:Aminoacyltransferases / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000378:metabolism; D018745:Genome, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D049931:Sesbania / Q000145:classification / Q000201:enzymology*
D018076:DNA, Complementary; D010940:Plant Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D019881:Aminoacyltransferases; C093784:glutathione gamma-glutamylcysteinyltransferase