title: Distinct biochemical activities and heat shock responses of two UDP-glucose sterol glucosyltransferases in cotton.
abstract: UDP-glucose sterol glucosyltransferase (SGT) are enzymes typically involved in the production of sterol glycosides (SG) in various organisms. However, the biological functions of SGTs in plants remain largely unknown. In the present study, we identified two full-length GhSGT genes in cotton and examined their distinct biochemical properties. Using UDP-[U-(14)C]-glucose and β-sitosterol or total crude membrane sterols as substrates, GhSGT1 and GhSGT2 recombinant proteins were detected with different enzymatic activities for SG production. The addition of Triton (X-100) strongly inhibited the activity of GhSGT1 but caused an eightfold increase in the activity of GhSGT2. The two GhSGTs showed distinct enzyme activities after the addition of NaCl, MgCl2, and ZnCl2, indicating that the two GhSGTs exhibited distinct biochemical properties under various conditions. Furthermore, after heat shock treatment, GhSGT1 showed rapidly enhanced gene expression in vivo and low enzyme activity in vitro, whereas GhSGT2 maintained extremely low gene expression levels and relatively high enzyme activity. Notably, the GhSGT2 gene was highly expressed in cotton fibers, and the biochemical properties of GhSGT2 were similar to those of GhCESA in favor for MgCl2 and non-reduction reaction condition. It suggested that GhSGT2 may have important functions in cellulose biosynthesis in cotton fibers, which must be tested in the transgenic plants in the future. Hence, the obtained data provided insights into the biological functions of two different GhSGTs in cotton and in other plants.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; College of Bioengineering, Jingchu University of Technology, Jingmen 448000, China.
authors.forename: Xianliang
authors.initials: X
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: Xiatao@mail.hzau.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Xia
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Huang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xuezhe
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shengqiu
authors.initials: S
authors.lastname: Feng
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: lpeng@mail.hzau.edu.cn.
authors.forename: Liangcai
authors.initials: L
authors.lastname: Peng
mesh_terms: D000595:Amino Acid Sequence; D032561:Cotton Fiber; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics; D018869:Heat-Shock Response; D008969:Molecular Sequence Data
chemical_list: D005964:Glucosyltransferases; C085360:sterol 3-beta-glucosyltransferase
keywords: Biochemical activities; Cotton fibers; Heat shock; Sterol glycosides; UDP-glucose sterol glucosyltransferase