title: Rice GTPase OsRacB: potential accessory factor in plant salt-stress signaling.
abstract: As the sole ubiquitous signal small guanosine triphosphate-binding protein in plants, Rop gene plays an important role in plant growth and development. In this study, we focus on the relationship between the novel rice Rop gene OsRacB and plant salt tolerance. Results show that OsRacB transcription is highly accumulated in roots after treatment with salinity, but only slightly accumulated in stems and leaves under the same treatment. Promoter analysis showed that OsRacB promoter is induced by salinity and exogenous salicylic acid, not abscisic acid. To elucidate its physiological function, we generated OsRacB sense and antisense transgenic tobacco and rice. Under proper salinity treatment, sense transgenic plants grew much better than the control. This suggests that overexpression of OsRacB in tobacco and rice can improve plant salt tolerance. But under the same treatment, no difference could be observed between OsRacB antisense plants and the control. The results indicated that OsRacB is only an accessory factor in plant salt tolerance.
authors.affiliation: Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Min
authors.initials: M
authors.lastname: Luo
authors.forename: Su-Hai
authors.initials: SH
authors.lastname: Gu
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Zhao
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.forename: Nai-Hu
authors.initials: NH
authors.lastname: Wu
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D020558:GTP Phosphohydrolases / Q000737:chemistry*; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005822:Genetic Vectors; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010940:Plant Proteins; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D012492:Salts / Q000494:pharmacology; D012639:Seeds / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics
chemical_list: D010940:Plant Proteins; D012492:Salts; D000040:Abscisic Acid; D020558:GTP Phosphohydrolases