Sci. STKE, 22 November 2005
PLANT WOUND RESPONSE Jasmonate Precursor, OPDA, Sends the Signal
Taki et al. used microarray analysis to show that, although some of the genes regulated by jasmonates (JAs) and the jasmonate precursor 12-oxo-phytodienoic acid (OPDA) are the same, OPDA also regulates the expression of a separate subset of genes. Selected genes were further evaluated using a mutant that could not convert OPDA to JA to verify that OPDA regulated their expression. Wounding regulated 50% of the genes affected by either exogenous JA or exogenous ODPA, consistent with JA and OPDA having roles in the wound response. Using two mutants in the biosynthetic pathway of JA--one downstream of OPDA and one upstream of OPDA--the authors provided further support for an OPDA-specific role in wound signaling. Unlike the effects of JAs, OPDA stimulation of gene expression appeared not to require the F-box protein COI1, because Arabidopsis coi1-16 mutants continued to exhibit OPDA-mediated gene transcription but lacked JA-mediated gene transcription. Thus, OPDA appears to activate a pathway that is separate from the JA pathway, which requires COI1.
N. Taki, Y. Sasaki-Sekimoto, T. Obayashi, A. Kikuta, K. Kobayashi, T. Ainai, K. Yagi, N. Sakurai, H. Suzuki, T. Masuda, K.-i. Takamiya, D. Shibata, Y. Kobayashi, H. Ohta, 12-oxo-phytodienoic acid triggers expression of a distinct set of genes and plays a role in wound-induced gene expression in Arabidopsis. Plant Phys. 139, 1268-1283 (2005). [Abstract] [Full Text]
Citation: Jasmonate Precursor, OPDA, Sends the Signal. Sci. STKE 2005, tw418 (2005).
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