Abscisic acid and water-stress induce the expression of a novel rice gene.
We have identified a novel rice gene, called RAB 21, which is induced when plants are subject to water-stress. This gene encodes a basic, glycine-rich protein (mol. wt 16,529) which has a duplicated domain structure. Immunoblots probed with antibodies raised against beta-galactosidase/RAB 21 fusion protein detect RAB 21 protein only in cytosolic cell fractions. RAB 21 mRNA and protein accumulate in rice embryos, leaves, roots and callus-derived suspension cells upon treatment with NaCl (200 mM) and/or the plant hormone abscisic acid (10 microM ABA). The effects of NaCl and ABA are not cumulative, suggesting that these two inducers share a common response pathway. Induction of RAB 21 mRNA accumulation by ABA is rapid (less than 15 min in suspension cells) and does not require protein synthesis, indicating that preformed nuclear and/or cytosolic factors mediate the response to this hormone. We have characterized the RAB 21 gene by determining the complete nucleotide sequence of a nearly full-length cDNA and corresponding genomic copy, and by mapping the start site of its major transcript. The proximal promoter region contains various GC-rich repeats.
Mundy
J
J
Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021.
Chua
N H
NH
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D004247:DNA / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000187:drug effects*; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000032:analysis; D012639:Seeds / Q000502:physiology; D014158:Transcription, Genetic
D003509:Cyclohexanecarboxylic Acids; D010940:Plant Proteins; D012333:RNA, Messenger; D000040:Abscisic Acid; D004247:DNA