Allene oxide synthase (AOS; hydroperoxide dehydratase; EC 4.2.1.92) catalyzes the first step in the biosynthesis of jasmonic acid from lipoxygenase-derived hydroperoxides of free fatty acids. Using the AOS cDNA from tomato (Lycopersicon esculentum), in which the role of jasmonic acid in wound-induced defense gene activation has been best described, we examined the kinetics of AOS induction in r...

Phytohormones exhibit a wide range of chemical structures, though they primarily originate from three key metabolic precursors: amino acids, isoprenoids, and lipids. Specific such as tryptophan, methionine, phenylalanine, arginine, contribute to the production various phytohormones, including auxins, melatonin, ethylene, salicylic acid, polyamines. Isoprenoids are foundation five phytohormone c...

12-oxo-phytodienoic acid and several phytoprostanes are cyclopentenone oxylipins that are formed via the enzymatic jasmonate pathway and a nonenzymatic, free radical-catalyzed pathway, respectively. Both types of cyclopentenone oxylipins induce the expression of genes related to detoxification, stress responses, and secondary metabolism, a profile clearly distinct from that of the cyclopentanon...

Crosstalk among different hormone signaling pathways play an important role in modulating plant response to both biotic and abiotic stress. Hormone activity is controlled by its bio-availability, which is again influenced by its biosynthesis. Thus, independent hormone biosynthesis pathways must be regulated and co-ordinated to mount an integrated response. One of the possibilities is to use cis...

The effect of the abiotic stress hormone abscisic acid on plant disease resistance is a neglected field of research. With few exceptions, abscisic acid has been considered a negative regulator of disease resistance. This negative effect appears to be due to the interference of abscisic acid with biotic stress signaling that is regulated by salicylic acid, jasmonic acid and ethylene, and to an a...