title: A comparison of aquaporin function in mediating stomatal aperture gating among drought-tolerant and sensitive varieties of rice (Oryza sativa L.).
abstract: Climate change drastically affects the cultivation of rice, and its production is affected significantly by water stress. Adaptation of a plant to water deficit conditions is orchestrated by efficient water uptake and a stringently regulated water loss. Transpiration remains the major means of water loss from plants and is mediated by microscopic pores called stomata. Stomatal aperture gating is facilitated by ion channels and aquaporins (AQPs) which regulate the turgidity of the guard cells. In a similar manner, efficient water uptake by the roots is regulated by the presence of AQPs in the plasma membrane of root cells. In this study, we compare the efficiency of transmembrane water permeability in guard cells and root protoplasts from drought-tolerant and sensitive varieties of Oryza sativa L. In this report, we studied the transmembrane osmotic water permeability (Pos) of guard cell and root protoplasts of drought-sensitive and tolerant cultivars. The guard cells isolated from the drought-sensitive lowland rice variety ADT-39 show significant low osmotic permeability than the drought-tolerant rice varieties of Anna (lowland) and Dodda Byra Nellu (DBN) (upland local land rice). There is no significant difference in relative gene expression patterns of PIPs (Plasma membrane Intrinsic Proteins "PIP1" and "PIP2" subfamilies) in guard cells isolated from ADT-39 and Anna. While the expression levels of AQP genes remain the same between ADT-39 and Anna, there is a drastic difference in their osmotic permeability in the guard cells in spite of a higher number of stomata in Anna and DBN, hinting at a more efficient gating mechanism of AQP in the stomata of the drought-tolerant varieties studied.
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Vinnakota
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: Anantha Maharasi
authors.initials: AM
authors.lastname: Ramakrishnan
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: A
authors.initials: A
authors.lastname: Samdani
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: M Anjali
authors.initials: MA
authors.lastname: Venugopal
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: B Sri
authors.initials: BS
authors.lastname: Ram
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India.
authors.forename: S Navaneetha
authors.initials: SN
authors.lastname: Krishnan
authors.affiliation: Regional Research Station, Tamil Nadu Agricultural University, Paiyur, Krishnagiri, 635112, India.
authors.forename: Dhandapani
authors.initials: D
authors.lastname: Murugesan
authors.affiliation: Ion channel Biology Laboratory, AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chromepet, Chennai, 600 044, India. skavitham@yahoo.com.
authors.forename: Kavitha
authors.initials: K
authors.lastname: Sankaranarayanan
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D002463:Cell Membrane Permeability; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D009995:Osmosis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000166:cytology / Q000502:physiology*; D011523:Protoplasts / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D020346:Aquaporins; D010940:Plant Proteins; D012333:RNA, Messenger; D014867:Water
keywords: ADT-39; Anna; Aquaporin; Dodda Byra Nellu; Guard cell; Osmotic permeability coefficient; Plasma membrane intrinsic proteins; Protoplasts; Transmembrane water permeability