| Title: | Systemin potentiates the oxidative burst in cultured tomato cells |
| Author(s): | Stennis MJ; Chandra S; Ryan CA; Low PS; |
| ISSN/ISBN: | 1532-2548 (Electronic) 0032-0889 (Print) 0032-0889 (Linking) |
| Abstract: | "Plants that have been wounded by insects or other herbivores may be more susceptible to infection by adventitious microbes. Wound-induced signal molecules, which serve to induce responses in the plant that retard further feeding, might also act to prepare a plant for possible pathogen attack. We have examined the effect of a wound-generated systemic messenger (systemin) on a pathogen-stimulated defense-response marker, the oxidative burst. We observed that neither systemin nor its inactive analog (A-17) was able to directly induce H2O2 biosynthesis in suspension-cultured tomato (Lycopersicon esculentum L.) cells, regardless of the duration of exposure of the cells to the two peptides. Similarly, neither systemin nor A-17 was capable of modifying an oligogalacturonide-elicited oxidative burst, as long as elicitor addition occurred within minutes of treatment with systemin or A-17. In contrast, preexposure of the cell cultures to systemin (but not to A-17) led to a time-dependent enhancement of the oligogalacturonide-elicited oxidative burst. By 12 h of exposure, the H2O2 biosynthetic capacity of systemin-treated cells exceeded that of the control cells by a factor of 16 +/- 2. A similar up-regulation by systemin of a mechanically stimulated oxidative burst was also observed. Because the systemin-induced augmentation in oxidant synthesis is quantitatively prevented by coincubation with 2 &mgr;M cycloheximide, and because the oxidative burst of oligogalacturonic acid-elicited control cells (no systemin exposure) is unaffected by preincubation with cycloheximide, we conclude that systemin enhancement of the tomato-cell oxidative burst requires protein synthesis" |
| Notes: | "PubMed-not-MEDLINEStennis, MJ Chandra, S Ryan, CA Low, PS eng 1998/07/15 Plant Physiol. 1998 Jul; 117(3):1031-6. doi: 10.1104/pp.117.3.1031" |
