Abstract
Methyl jasmonate (MeJA), a methyl ester of jasmonic acid (JA), is a well-established signal molecule in plant defense responses and an effective inducer of secondary metabolite accumulation in plant cell cultures such as the valuable anticancer diterpenoid taxol (paclitaxel) in Taxus spp. This work examines the involvement of nitric oxide (NO) in MeJA-induced plant defense responses and secondary metabolism in Taxus chinensis cell cultures. Exogenously supplied MeJA at 100 μM induced rapid production of NO in the Taxus cell cultures, reaching a maximum within 6 h of MeJA supply. Several other responses occurred concomitantly, including the production of hydrogen peroxide (H2O2), and the increases in intracellular malondialdehyde (MDA) content, lipoxygenase (LOX) and phenylalanine ammonium-lyase (PAL) activities. The MeJA-induced H2O2production was suppressed by an NO donor, sodium nitroprusside (SNP), but enhanced by NO inhibitors, Nω-nitro-L-arginine (L-NNA) and 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO). In contrast, the MeJA-induced MDA, LOX and PAL were all enhanced by the NO donor but suppressed by the NO inhibitors. The NO inhibitors also suppressed MeJA-induced taxol accumulation. These results are suggestive of a role for NO as a signal element for activating the MeJA-induced defense responses and secondary metabolism activities of plant cells.
Original language | English |
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Pages (from-to) | 923-930 |
Number of pages | 8 |
Journal | Plant and Cell Physiology |
Volume | 46 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1 Jun 2005 |
Keywords
- Methyl jasmonate
- Nitric oxide
- Oxidative responses
- Paclitaxel production
- Phenylalanine ammonium-lyase
- Taxus cell culture
ASJC Scopus subject areas
- General Medicine
- Physiology
- Plant Science
- Cell Biology