Mapping Plants' Transcriptional Response to Jasmonates

Jasmonates (JAs) are plant signaling molecules implicated in the regulation of various developmental and physiological responses. Studies have related JAs to fruit ripening, male fertility and root growth. JAs are also synthesized in large quantities during pathogen intrusion. Upon perception of jasmonate signals, plants activate various defense mechanisms like production of secondary metabolites. This is reflected in a massive gene expression reprogramming. Scientists from Ghent University monitored the changes in the gene expression profile of the model plant Arabidopsis upon exposure to jasmonates.

Early response to JA exposure includes activation of genes coding for proteins that regulate the JA biosynthetic pathway. The researchers identified genes coding for transcription factors (elements that can promote or down-regulate transcription) not previously associated with JA signaling. In a second wave of response, JA was found to reprogram the cell metabolism and cell cycle progression. Expression of genes coding for lignin precursors were increased significantly. Lignin is an integral part of plant cell walls. The discoveries made by the scientists will be essential in mapping the complete JA signaling pathway.

The abstract of the paper published by PNAS is available at http://www.pnas.org/cgi/content/abstract/0711203105v1