title: Arabidopsis AtVPS15 plays essential roles in pollen germination possibly by interacting with AtVPS34.
abstract: VPS15 protein is a component of the phosphatidylinositol 3-kinase complex which plays a pivotal role in the development of yeast and mammalian cells. The knowledge about the function of its homologue in plants remains limited. Here we report that AtVPS15, a homologue of yeast VPS15p in Arabidopsis, plays an essential role in pollen germination. Homozygous T-DNA insertion mutants of AtVPS15 could not be obtained from the progenies of self-pollinated heterozygous mutants. Reciprocal crosses between atvps15 mutants and wild-type Arabidopsis revealed that the T-DNA insertion was not able to be transmitted by male gametophytes. DAPI staining, Alexander's stain and scanning electron microscopic analysis showed that atvps15 heterozygous plants produced pollen grains that were morphologically indistinguishable from wild-type pollen, whereas in vitro germination experiments revealed that germination of the pollen grains was defective. GUS staining analysis of transgenic plants expressing the GUS reporter gene driven by the AtVPS15 promoter showed that AtVPS15 was mainly expressed in pollen grains. Finally, DUALmembrane yeast two-hybrid analysis demonstrated that AtVPS15 might interact directly with AtVPS34. These results suggest that AtVPS15 is very important for pollen germination, possibly through modulation of the activity of PI3-kinase.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Wei-Ying
authors.initials: WY
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Shufan
authors.initials: S
authors.lastname: Xing
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Ma
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.forename: Hongya
authors.initials: H
authors.lastname: Gu
authors.forename: Genji
authors.initials: G
authors.lastname: Qin
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Qu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D058546:Class III Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011058:Pollen / Q000378:metabolism* / Q000502:physiology*; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D020798:Two-Hybrid System Techniques; D058571:Vacuolar Sorting Protein VPS15 / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D058546:Class III Phosphatidylinositol 3-Kinases; D058571:Vacuolar Sorting Protein VPS15