title: Phosphatidylinositol 3-Kinase Promotes Activation and Vacuolar Acidification and Delays Methyl Jasmonate-Induced Leaf Senescence.
abstract: PI3K and its product PI3P are both involved in plant development and stress responses. In this study, the down-regulation of PI3K activity accelerated leaf senescence induced by methyl jasmonate (MeJA) and suppressed the activation of vacuolar H(+)-ATPase (V-ATPase). Yeast two-hybrid analyses indicated that PI3K bound to the V-ATPase B subunit (VHA-B). Analysis of bimolecular fluorescence complementation in tobacco guard cells showed that PI3K interacted with VHA-B2 in the tonoplasts. Through the use of pharmacological and genetic tools, we found that PI3K and V-ATPase promoted vacuolar acidification and stomatal closure during leaf senescence. Vacuolar acidification was suppressed by the PIKfyve inhibitor in 35S:AtVPS34-YFP Arabidopsis during MeJA-induced leaf senescence, but the decrease was lower than that in YFP-labeled Arabidopsis. These results suggest that PI3K promotes V-ATPase activation and consequently induces vacuolar acidification and stomatal closure, thereby delaying MeJA-induced leaf senescence.
authors.affiliation: MOE Key Laboratory of Laser Life Science, and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China (J.L., Y.J., J.Z., D. X.).
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: MOE Key Laboratory of Laser Life Science, and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China (J.L., Y.J., J.Z., D. X.).
authors.forename: Yingbin
authors.initials: Y
authors.lastname: Ji
authors.affiliation: MOE Key Laboratory of Laser Life Science, and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China (J.L., Y.J., J.Z., D. X.).
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: MOE Key Laboratory of Laser Life Science, and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China (J.L., Y.J., J.Z., D. X.). xingda@scnu.edu.cn.
authors.forename: Da
authors.initials: D
authors.lastname: Xing
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000143:Acids / Q000737:chemistry; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western; D003517:Cyclopentanes / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D054883:Oxylipins / Q000494:pharmacology; D058539:Phosphatidylinositol 3-Kinase / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D054046:Plant Stomata / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000085:Acetates; D000143:Acids; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D021122:Protein Subunits; C072239:methyl jasmonate; D058539:Phosphatidylinositol 3-Kinase; D025262:Vacuolar Proton-Translocating ATPases