Diverse environmental cues transiently regulate OsOPR1 of the "octadecanoid pathway" revealing its importance in rice defense/stress and development.
Previously, we reported rice (Oryza sativa L. japonica type cv. Nipponbare) allene oxide synthase (OsAOS) and cyclase (OsAOC) genes of the octadecanoid pathway. Here we have isolated a 12-oxo-phytodienoic acid reductase gene, called OsOPR1, encoding the last committed enzymatic step on the octadecanoid pathway leading to jasmonic acid (JA) biosynthesis. OsOPR1 encodes a 380 amino acid long polypeptide with a predicted molecular mass of 42465.02 and pI of 5.79, and belongs to a gene family in the rice genome. Transcriptional profiling using our established two-week-old rice seedling model system against a variety of environmental factors such as wounding, global signals (including JA), osmotic stresses, heavy metals, UV-C irradiation, fungal elicitor, protein phosphatase inhibitors, and gaseous pollutants indicated that OsOPR1 transcript was rapidly, transiently and differentially up-regulated within 30 min in leaves. Surprisingly, co-application of signaling molecules JA, salicylate and ethylene, resulted in a massive accumulation of the OsOPR1 transcript at 30 min and remained elevated with time, a new observation. Furthermore, transient expression of OsOPR1, most likely regulated by a de novo synthesized negative trans-acting factor(s), was evidenced by the use of cycloheximide. Finally, the endogenous OsOPR1 expression varied with the stage of plant development. These results strongly suggest a regulatory role for OsOPR1 in rice plant defense/stress response pathway(s) and reproduction.
Agrawal
Ganesh K
GK
Bio-Resource Research and Development Company Pvt. Ltd. (BIRD), G.P.O. Box 8207, Kathmandu, Nepal. gkagrawal@onebox.com
Jwa
Nam-Soo
NS
Shibato
Junko
J
Han
Oksoo
O
Iwahashi
Hitoshi
H
Rakwal
Randeep
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D018076:DNA, Complementary; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D012275:Oryza / Q000276:immunology / Q000502:physiology*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D010940:Plant Proteins