title: Overexpression of GsGSTU13 and SCMRP in Medicago sativa confers increased salt-alkaline tolerance and methionine content.
abstract: Tau-class glutathione S-transferases (GSTUs) are ubiquitous proteins encoded by a large gene family in plants, which play important roles in combating different environmental stresses. In previous studies, we constructed a Glycine soja transcriptional profile, and identified three GSTUs (GsGSTU13, GsGSTU14 and GsGSTU19) as potential salt-alkaline stress-responsive genes. Two of them, GsGSTU14 and GsGSTU19, have been shown to positively regulate plant salt-alkaline tolerance. In this study, we further demonstrated the positive function of GsGSTU13 in plant salt-alkaline stress responses by overexpressing it in Medicago sativa. Stress tolerance tests suggested that GsGSTU13 transgenic lines showed better growth and physiological indicators than wild alfalfa (cv. Zhaodong) under alkaline stress. Considering the shortage of methionine in alfalfa, we then co-transformed GsGSTU13 into two main alfalfa cultivars in Heilongjiang Province (cv. Zhaodong and cv. Nongjing No. 1) together with SCMRP, a synthesized gene that could improve the methionine content. We found that GsGSTU13/SCMRP transgenic alfalfa displayed not only higher methionine content but also higher tolerance to alkaline and salt stresses, respectively. Taken together, our results demonstrate that GsGSTU13 acts as a positive regulator in plant responses to salt and alkaline stresses, and can be used as a good candidate for generation of salt-alkaline tolerant crops.
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Bowei
authors.initials: B
authors.lastname: Jia
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Mingzhe
authors.initials: M
authors.lastname: Sun
authors.affiliation: Agricultural College, Heilongjiang Bayi Agricultural University, Daqing 163319, P.R. China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory of Molecular Biology, College of Heilongjiang Province, Heilongjiang University, Harbin 150080, P.R. China.
authors.forename: Rongtian
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Huizi
authors.initials: H
authors.lastname: DuanMu
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Jialei
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Agricultural Biological Functional Gene, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Zhu