Characterization of OsPIP2;7, a water channel protein in rice

• Published in: Plant and cell physiology 2008-12, Vol.49 (12), p.1851-1858
• Main Authors: Li, G.W.(Chinese Academy of Sciences, Shanghai (China)), Zhang, M.H, Cai, W.M, Sun, W.N, Su, W.A
• Format: Article
• Language: English
• Subjects: AGUA; Aquaporins - genetics; Aquaporins - metabolism; CLONACION; CLONAGE; CLONING; Cloning, Molecular; COLD STRESS; Cold Temperature; EAU; ESTRES DE FRIO; GENE; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; GENES; In situ hybridization expression; Low temperature stress; MEMBRANA; MEMBRANE; MEMBRANES; Oryza - genetics; Oryza - metabolism; ORYZA SATIVA; Osmosis; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - genetics; Plant Roots - metabolism; Plant Transpiration; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Rice; RNA, Plant - genetics; STRESS DU AU FROID; TEMPERATURA; TEMPERATURE; TRANSGENIC PLANTS; WATER; Water channel activity; Xenopus; Yeast
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcn166

Aquaporins are water channel proteins that facilitate passage of water and other small neutral molecules across biological membranes. There are usually a large number of members of this family in higher plants, which exhibit various physiological functions and are regulated in a time-specific and particular mode. We have previously shown that a rice gene, OsPIP2;7, was generally up-regulated in roots but down-regulated in shoots at the early stage of chilling stress. Here, OsPIP2;7 was cloned and proved to be an aquaporin with high activity in Xenopus oocytes. OsPIP2;7 was localized mainly in mesophyll cells of leaves. In roots it was detected in the vascular tissues, epidermis cells and exodermis cells at the elongation zone, as well as in the epidermis cells, exodermis cells and root hair at the maturation zone. Yeast cells overexpressing OsPIP2;7 showed a higher survival rate after freeze-thaw stress. Furthermore, OsPIP2;7 enhanced the transpiration rate and tolerance to low temperature when overexpressed in rice. These results indicated that OsPIP2;7 was involved in rapid water transport and maintenance of the water balance in cells, and ultimately improves the tolerance of yeast and rice to low temperature stress.