Overexpression of OsRab7B3, a small GTP-binding protein gene, enhances leaf senescence in transgenic rice.
Rab family proteins are small GTP-binding proteins involved in intracellular trafficking. They play critical roles in several plant development processes. Different expression patterns of 46 Rabs in the rice genome were examined in various rice tissues and in leaves treated with plant growth regulators and under senescence conditions. One of the OsRab genes, OsRab7B3, closely associated with senescence in expression pattern, was chosen for functional analysis. Expression of sGFP under the control of the OsRab7B3 promoter increased in leaves when ABA and NaCl were applied or when kept in dark. In transgenic rice overexpressing OsRab7B3, the senescence-related genes were upregulated and leaf senescence was significantly enhanced under dark conditions. Moreover, leaf yellowing occurred earlier in the transgenic plants than in the wild type at the ripening stage. Hence it is suggested that OsRab7B3 act as a stress-inducible gene that plays an important role in the leaf senescence process.
Department of Biology, Faculty of Science, Chiang Mai University, Muang, Chiang Mai, Thailand.
Sugunya
S
Pitakrattananukool
Taiji
T
Kawakatsu
Somboon
S
Anuntalabhochai
Fumio
F
Takaiwa
D000040:Abscisic Acid / Q000494:pharmacology; D000375:Aging / Q000187:drug effects; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008027:Light; D012275:Oryza / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D012965:Sodium Chloride / Q000494:pharmacology; D020691:rab GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism
D007527:Isoenzymes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D019204:GTP-Binding Proteins; D020691:rab GTP-Binding Proteins