title: Aquaporins in developing rice grains.
abstract: During rice grain filling, grain moisture content and weight show dynamic changes. We focused on the expression of all 33 rice aquaporins in developing grains. Only two aquaporin genes, OsPIP2;1 and OsTIP3;1, were highly expressed in the period 10-25 days after heading (DAH). High-temperature treatment from 7 to 21 DAH abolished the dynamic up-regulation of OsPIP2;1 in the period 15-20 DAH, whereas OsTIP3;1 expression was not affected. Immunohistochemical analysis revealed that OsPIP2;1 was present in the starchy endosperm, nucellar projection, nucellar epidermis, and dorsal vascular bundles, but not in the aleurone layer. OsTIP3;1 was present in the aleurone layer and starchy endosperm. Water transport activity of recombinant OsTIP3;1 was low, in contrast to the high activity of recombinant OsPIP2;1 we reported previously. Our data suggest that OsPIP2;1 and OsTIP3;1 have distinct roles in developing grains.
authors.affiliation: a Agro-Production Technologies and Management Research Division , NARO Tohoku Agricultural Research Center , Morioka , Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Hayashi
authors.forename: Junko
authors.initials: J
authors.lastname: Ishikawa-Sakurai
authors.forename: Mari
authors.initials: M
authors.lastname: Murai-Hatano
authors.forename: Arifa
authors.initials: A
authors.lastname: Ahamed
authors.forename: Matsuo
authors.initials: M
authors.lastname: Uemura
mesh_terms: D020346:Aquaporins / Q000096:biosynthesis* / Q000235:genetics; D002523:Edible Grain / Q000235:genetics* / Q000254:growth & development; D056625:Endosperm / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D014867:Water / Q000378:metabolism
chemical_list: D020346:Aquaporins; D014867:Water
keywords: Oryza sativa; aleurone layer; aquaporin; developing grain; phloem