Methyl jasmonate elicits rapid changes in carbon and nitrogen dynamics in tomato

P>Evidence is emerging to support the notion that in response to herbivory, plants undergo changes in their primary metabolism and are able to fine-tune the allocation of new and existing resources and temporarily direct them to storage organs. We hypothesized that simulated herbivory increases the export of resources out of the affected tissues and increases allocation to roots. We used short-lived radioisotopes to study in vivo the dynamics of newly incorporated 11CO(2) and 13NH(3). Methyl jasmonate (MeJA), a known defense elicitor, was applied to the foliage of tomato plants and 4 h later we monitored leaf uptake, export and whole-plant allocation of [11C]photosynthate and [13N]amino acids. There was a marginally significant decrease in the fixation of 11CO(2), and an increase in the export of newly acquired carbon and nitrogen out of MeJA-treated leaves. The proportion of nitrogen allocated to roots increased, whereas the proportion of carbon did not change. These results are in agreement with our hypotheses, showing a change in the allocation of resources after treatment with MeJA; this may reduce the chance of resources being lost to herbivores and act as a buffer to biotic stress by increasing the potential for plant regrowth and survival after the attack.