Transport functions and expression analysis of vacuolar membrane aquaporins in response to various stresses in rice

J Plant Physiol. 2008 Dec;165(18):1879-88. doi: 10.1016/j.jplph.2008.05.002. Epub 2008 Aug 15.

Abstract

The vacuole, a multifunctional organelle of most plant cells, has very important roles in space filling, osmotic adjustment, storage and digestion. Previous researches suggested that aquaporins in the tonoplast were involved in vacuolar functions. The rice genome contains 33 aquaporin genes, 10 of which encode tonoplast intrinsic proteins (TIPs). However, the function of each individual TIP isoform and the integrated function of TIPs under various physiological conditions remain elusive. Here, five rice TIP members were characterized with water and/or glycerol transport activities using the Xenopus oocyte expression system. OsTIP1;2, OsTIP2;2, OsTIP4;1 and OsTIP5;1 possessed water transport activity. OsTIP1;2, OsTIP3;2 and OsTIP4;1 were demonstrated with glycerol transport activity. Rice TIP expression patterns under various abiotic stress conditions including dehydration, high salinity, abscisic acid (ABA) and during seed germination were investigated by real-time PCR. OsTIP1s (OsTIP1;1 and OsTIP1;2) were highly expressed during seed germination, whereas OsTIP3s (OsTIP3;1 and OsTIP3;2) were specifically expressed in mature seeds with a decrease in expression levels upon germination. The results of this research provided a functional and expression profiles of rice TIPs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Animals
  • Aquaporins / genetics*
  • Aquaporins / metabolism
  • Biological Transport / drug effects
  • Dehydration
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant* / drug effects
  • Germination / drug effects
  • Germination / genetics
  • Glycerol / metabolism
  • Intracellular Membranes / drug effects
  • Intracellular Membranes / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Oocytes / drug effects
  • Oocytes / metabolism
  • Oryza / drug effects
  • Oryza / genetics*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Shoots / drug effects
  • Plant Shoots / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Salinity
  • Seedlings / drug effects
  • Seedlings / genetics
  • Seeds / drug effects
  • Seeds / genetics
  • Stress, Physiological / drug effects
  • Stress, Physiological / genetics*
  • Vacuoles / drug effects
  • Vacuoles / metabolism*
  • Water / metabolism
  • Xenopus

Substances

  • Aquaporins
  • Membrane Proteins
  • Plant Proteins
  • RNA, Messenger
  • tonoplast intrinsic protein, plant
  • Water
  • Abscisic Acid
  • Glycerol