title: The putative auxin efflux carrier OsPIN3t is involved in the drought stress response and drought tolerance.
abstract: The phytohormone auxin plays a critical role in plant growth and development, and its spatial distribution largely depends on the polar localization of the PIN-FORMED (PIN) auxin efflux carrier family members. In this study, we identify a putative auxin efflux carrier gene in rice, OsPIN3t, which acts in auxin polar transport but is also involved in the drought stress response in rice. We show that OsPIN3t-GFP fusion proteins are localized in plasma membranes, and this subcellular localization changes under 1-N-naphthylphthalamic acid (NPA) treatment. The tissue-specific expression patterns of OsPIN3t were also investigated using a β-glucuronidase (GUS) reporter, which showed that OsPIN3t was mainly expressed in vascular tissue. The GUS activity in OsPIN3tpro::GUS plants increased by NAA treatment and decreased by NPA treatment. Moreover, knockdown of OsPIN3t caused crown root abnormalities in the seedling stage that could be phenocopied by treatment of wild-type plants with NPA, which indicated that OsPIN3t is involved in the control of polar auxin transport. Overexpression of OsPIN3t led to improved drought tolerance, and GUS activity significantly increased when OsPIN3tpro::GUS plants were subjected to 20% polyethylene glycol stress. Taken together, these results suggest that OsPIN3t is involved in auxin transport and the drought stress response, which suggests that a polar auxin transport pathway is involved in the regulation of the response to water stress in plants.
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei 050024, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuning
authors.initials: S
authors.lastname: Yan
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhao
authors.forename: Yujing
authors.initials: Y
authors.lastname: Li
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Qi
authors.forename: Zongxiu
authors.initials: Z
authors.lastname: Sun
authors.forename: Zhengge
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000502:physiology*; D010797:Phthalimides / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D007210:Indoleacetic Acids; C449300:PIN3 protein, Arabidopsis; D010797:Phthalimides; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C002687:alpha-naphthylphthalamic acid