title: ZmGOLS2, a target of transcription factor ZmDREB2A, offers similar protection against abiotic stress as ZmDREB2A.
abstract: GALACTINOL SYNTHASE is the first committed enzyme in the raffinose biosynthetic pathway. We have previously characterized the maize (Zea mays) GALACTINOL SYNTHASE2 gene (ZmGOLS2) as abiotic stress induced. To further investigate the regulation of ZmGOLS2 gene expression, individual luciferase expression vectors,in which the luciferase gene was controlled by different lengths of the ZmGOLS2 promoter, were co-transfected into maize protoplasts with either a ZmDREB2A- or a GFP-expression vector. Over-expression of ZmDREB2A up-regulated both the expression of the luciferase gene controlled by the ZmGOLS2 promoter and the endogenous ZmGOLS2 gene in protoplasts. Only one of the two DRE elements in the ZmGOLS2 promoter was identified as necessary for this up-regulation. Expression vectors of GFP, ZmGOLS2 or ZmDREB2A were stably transformed into Arabidopsis. Expression of ZmDREB2A up-regulated the AtGOLS3 gene but only over-expression of ZmGOLS2 resulted in hyper-accumulation of galactinol and raffinose. Regardless, under drought-, heat shock-, high osmotic- or salinity-stress conditions, both the ZmGOLS2- and the ZmDREB2A- expressing plants had greater germination percentages, greater percentages of seedlings becoming autotropic, and/or greater survival percentages during/after stress than the control plants. Under normal growing conditions, transgenic Arabidopsis plants expressing the ZmGOLS2 gene had similar growth to that of untransformed wild type or GFP-expressing control plants, whereas ZmDREB2A over-expressing plants exhibited retarded growth relative to either of the controls. These data suggest that over-expression of ZmGOLS2, rather than the transcription factor ZmDREB2A, is a more practical target for generation of abiotic-stress tolerant crops.
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.|Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.|Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Yumin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.|Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Mingshuai
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China.|Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Horticulture, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: Lynnette M A
authors.initials: LM
authors.lastname: Dirk
authors.affiliation: Department of Horticulture, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Downie
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China. tzhao2@nwsuaf.edu.cn.|Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China. tzhao2@nwsuaf.edu.cn.
authors.forename: Tianyong
authors.initials: T
authors.lastname: Zhao
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D055864:Droughts; D005700:Galactosyltransferases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018525:Germination; D018869:Heat-Shock Response; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011523:Protoplasts; D011887:Raffinose / Q000378:metabolism; D054712:Salinity; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D015854:Up-Regulation; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D005700:Galactosyltransferases; C096645:inositol 1-alpha-galactosyltransferase; D011887:Raffinose
keywords: Abiotic stress tolerance; DREB2A; Galactinol synthase; Maize