title: Up-regulation and interaction of the plasma membrane H(+)-ATPase and the 14-3-3 protein are involved in the regulation of citrate exudation from the broad bean (Vicia faba L.) under Al stress.
abstract: Our previous study showed that citrate excretion coupled with a concomitant release of protons was involved in aluminum (Al) resistance in the broad bean. Furthermore, genes encoding plasma membrane (PM) H(+)-ATPase (vha2) and the 14-3-3 protein (vf14-3-3b) were up-regulated by Al in Al-resistant (YD) broad bean roots. In this study, the roles of PM H(+)-ATPase (E.C. 3.6.3.6) and the 14-3-3 protein in the regulation of citrate secretion were further investigated in Al-resistant (YD) and Al-sensitive (AD) broad bean cultivars under Al stress. The results showed that greater citrate exudation was positively correlated with higher activities of PM H(+)-ATPase in roots of YD than AD. Real-time RT-PCR analysis revealed that vha2 was clearly up-regulated by Al in YD but not in AD roots, whereas the transcription levels of vf14-3-3b were elevated in a time-dependent manner in both YD and AD roots. Immunoprecipitation and Western analysis suggested that phosphorylation and interaction with the vf14-3-3b protein of the VHA2 were enhanced in YD roots but not in AD roots with increasing Al treatment time. Fusicoccin or adenosine 5'-monophosphate increased or decreased the interaction between the phosphorylated VHA2 and the vf14-3-3b protein, followed by an enhancement or reduction of the PM H(+)-ATPase activity and citrate exudation in both cultivars under Al stress conditions, respectively. Taken together, these results suggested that Al enhanced the expression and interaction of the PM H(+)-ATPase and the 14-3-3 protein, which thereby led to higher activity of the PM H(+)-ATPase and more citrate exudation from YD plants.
authors.affiliation: Biotechnology Research Centre, Faculty of Life Science and Biotechnology, Chenggong Campus, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Chuan-Long
authors.initials: CL
authors.lastname: Guo
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Xuan-Qin
authors.initials: XQ
authors.lastname: Chen
authors.forename: Kong-Huan
authors.initials: KH
authors.lastname: Wu
authors.forename: Kui-Zhi
authors.initials: KZ
authors.lastname: Li
authors.forename: Yong-Xiong
authors.initials: YX
authors.lastname: Yu
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Chen
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism*; D000222:Adaptation, Physiological / Q000235:genetics; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000535:Aluminum / Q000009:adverse effects* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D019343:Citric Acid / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006027:Glycosides / Q000494:pharmacology; D010766:Phosphorylation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation; D031307:Vicia faba / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; D006027:Glycosides; D010940:Plant Proteins; C007808:fusicoccin; D019343:Citric Acid; D000249:Adenosine Monophosphate; D000535:Aluminum; D006180:Proton-Translocating ATPases
keywords: 1,3-bis-[tris(hy- droxymethyl)-methylamino]-propane; 14-3-3 Protein; 5’-AMP; AD; Al; Al stress; BTP; Broad bean; Citrate exudation; DDT; FC; OA; PM; PMSF; Plasma membrane H(+)-ATPase; VHA2p; Vicia faba 14-3-3-like protein b; Vicia faba plasma membrane H(+)-ATPase; Vicia faba. L cv. Anhui Candou; Vicia faba. L cv. Yunnan Candou 8363; YD; adenosine 5′-monophosphate; aluminum; dithiothreitol; fusicoccin; organic acid; phenylmethylsulfonyl fluoride; phosphorylated VHA2 at Thr-951 in C terminus; plasma membrane; vf14-3-3b; vha2