128649 - Altered expression of the malate-permeable anion channel OsALMT4 reduces the growth of rice under low radiance.pdf (1.59 MB)
Altered expression of the malate-permeable anion channel OsALMT4 reduces the growth of rice under low radiance
journal contributionposted on 2023-05-19, 21:46 authored by Liu, J, Xu, M, Estavillo, GM, Delhaize, E, White, RG, Meixue ZhouMeixue Zhou, Ryan, PR
We examined the function of OsALMT4 in rice (Oryza sativa L.) which is a member of the aluminum-activated malate transporter family. Previous studies showed that OsALMT4 localizes to the plasma membrane and that expression in transgenic rice lines results in a constitutive release of malate from the roots. Here, we show that OsALMT4 is expressed widely in roots, shoots, flowers, and grain but not guard cells. Expression was also affected by ionic and osmotic stress, light and to the hormones ABA, IAA, and salicylic acid. Malate efflux from the transgenic plants over-expressing OsALMT4 was inhibited by niflumate and salicylic acid. Growth of transgenic lines with either increased OsALMT4 expression or reduced expression was measured in different environments. Light intensity caused significant differences in growth between the transgenic lines and controls. When day-time light was reduced from 700 to 300 μmol m-2s-1 independent transgenic lines with either increased or decreased OsALMT4 expression accumulated less biomass compared to their null controls. This response was not associated with differences in photosynthetic capacity, stomatal conductance or sugar concentrations in tissues. We propose that by disrupting malate fluxes across the plasma membrane carbon partitioning and perhaps signaling are affected which compromises growth under low light. We conclude that OsALMT4 is expressed widely in rice and facilitates malate efflux from different cell types. Altering OsALMT4 expression compromises growth in low-light environments.
Grains Research & Development Corporation
Publication titleFrontiers in Plant Science
Department/SchoolTasmanian Institute of Agriculture (TIA)
PublisherFrontiers Research Foundation
Place of publicationSwitzerland
Rights statementCopyright © 2018 Liu, Xu, Estavillo, Delhaize, White, Zhou and Ryan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.