title: A novel chloroplast protein, CEST induces tolerance to multiple environmental stresses and reduces photooxidative damage in transgenic Arabidopsis.
abstract: Environmental stresses are major factors in limiting plant growth and crop production. To find genes improving salt tolerance, the screening of a large population of transgenic Arabidopsis thaliana that expressed rice full-length cDNAs under salinity stress is reported here. In this study one of the isolated salt-tolerant lines, R07303 was analysed in detail. An uncharacterized rice gene CHLOROPLAST PROTEIN-ENHANCING STRESS TOLERANCE (OsCEST) was integrated in R07303. Newly constructed transgenic Arabidopsis that overexpressed OsCEST or its Arabidopsis homologue AtCEST showed improved tolerance to salinity stress. OsCEST and AtCEST were mainly transcribed in photosynthetic tissues. Green fluorescent protein-fused OsCEST and AtCEST proteins were localized to the chloroplast in the Arabidopsis leaf protoplasts. CEST-overexpressing Arabidopsis showed enhanced tolerance not only to salt stress but also to drought stress, high-temperature stress, and paraquat, which causes photooxidative stress. Under saline conditions, overexpression of CESTs modulated the stress-induced impairment of photosynthetic activity and the peroxidation of lipids. Reduced expression of AtCEST because of double-stranded RNA interference resulted in the impairment of photosynthetic activity, the reduction of green pigment, defects in chloroplast development, and growth retardation under light. This paper discusses the relationship between the chloroplast protein CEST and photooxidative damage.
authors.affiliation: Research Institute for Biological Sciences, Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, 7549-1 Yoshikawa, Kibi-chuo, Okayama 716-1241, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Yokotani
authors.forename: Mieko
authors.initials: M
authors.lastname: Higuchi
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kondou
authors.forename: Takanari
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Iwabuchi
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Hirochika
authors.forename: Minami
authors.initials: M
authors.lastname: Matsui
authors.forename: Kenji
authors.initials: K
authors.lastname: Oda
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D006358:Hot Temperature; D008027:Light; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress / Q000528:radiation effects; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D055049:Salt Tolerance; D016415:Sequence Alignment; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; C557281:CEST protein, Arabidopsis; D010940:Plant Proteins