title: Characterization of a vacuolar H+-ATPase G subunit gene from Juglans regia (JrVHAG1) involved in mannitol-induced osmotic stress tolerance.
abstract: JrVHAG1 is an important candidate gene for plant osmotic tolerance regulation. Vacuolar H+-ATPase (V-ATPase) is important for plant responses to abiotic stress; the G subunit is a vital part of V-ATPase. In this study, a G subunit of V-ATPase was cloned from Juglans regia (JrVHAG1) and functionally characterized. JrVHAG1 transcription was induced by mannitol that increasing 17.88-fold in the root at 12 h and 19.16-fold in the leaf at 96 h compared to that under control conditions. JrVHAG1 was overexpressed in Arabidopsis and three lines (G2, G6, and G9) with highest expression levels were selected for analysis. The results showed that under normal conditions, the transgenic and wild-type (WT) plants displayed similar germination, biomass accumulation, reactive oxygen species (ROS) level, and physiological index. However, when treated with mannitol, the fresh weight, root length, water-holding ability, and V-ATPase, superoxide dismutase, and peroxidase activity of G2, G6, and G9 were significantly higher than those of WT. In contrast, the ROS and cell damage levels of the transgenic seedlings were lower than those of WT. Furthermore, the transcription levels of V-ATPase subunits, ABF, DREB, and NAC transcription factors (TFs), all of which are factors of ABA signaling pathway, were much higher in JrVHAG1 transgenic plants than those in WT. The positive induction of JrVHAG1 gene under abscisic acid (ABA) treatments in root and leaf tissues indicates that overexpression of JrVHAG1 improves plant tolerance to osmotic stress relating to the ABA signaling pathway, which is transcriptionally activated by ABF, DREB, and NAC TFs, and correlated to ROS scavenging and V-ATPase activity.
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 498 Shaoshan South Road, Changsha, 410004, Hunan, China.|College of Chemistry and Environment Engineering, Hunan City University, 518 Yingbin Road, Yiyang, 413000, Hunan, China.
authors.forename: Zhenggang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 498 Shaoshan South Road, Changsha, 410004, Hunan, China.
authors.forename: Yunlin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Forestry, Hubei University for Nationalities, 39 Xueyuan Road, Enshi, 445000, Hubei, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ge
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 498 Shaoshan South Road, Changsha, 410004, Hunan, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Peng
authors.affiliation: College of Chemistry and Environment Engineering, Hunan City University, 518 Yingbin Road, Yiyang, 413000, Hunan, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Dong
authors.affiliation: Laboratory of Walnut Research Center, College of Forestry, Northwest A&F University, Yangling, 712100, Shaanxi, China. yangguiyan@yahoo.com.
authors.forename: Guiyan
authors.initials: G
authors.lastname: Yang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018533:Biomass; D016923:Cell Death / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D031324:Juglans / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D008353:Mannitol / Q000494:pharmacology*; D009997:Osmotic Pressure / Q000187:drug effects*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D021122:Protein Subunits / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D014170:Transformation, Genetic / Q000187:drug effects; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D021122:Protein Subunits; D017382:Reactive Oxygen Species; D008353:Mannitol; D000040:Abscisic Acid; D025262:Vacuolar Proton-Translocating ATPases
keywords: Juglans regia; Osmotic tolerance; ROS scavenger; V-ATPase G subunit