BIOSYNTHESIS AND ACTION OF JASMONATES IN PLANTS

Jasmonic acid and its derivatives can modulate aspects of fruit ripeni ng, production of viable pollen, root growth, tendril coiling, and pla nt resistance to insects and pathogens. Jasmonate activates genes invo lved in pathogen and insect resistance, and genes encoding vegetative storage proteins, but represses genes encoding proteins involved in ph otosynthesis. Jasmonic acid is derived from linolenic acid, and most o f the enzymes in the biosynthetic pathway have been extensively charac terized. Modulation of lipoxygenase and allene oxide synthase gene exp ression in transgenic plants raises new questions about the compartmen tation of the biosynthetic pathway and its regulation. The activation of jasmonic acid biosynthesis by cell wall elicitors, the peptide syst emin, and other compounds will be related to the function of jasmonate s in plants. Jasmonate modulates gene expression at the level of trans lation, RNA processing, and transcription. Promoter elements that medi ate responses to jasmonate have been isolated. This review covers rece nt advances in our understanding of how jasmonate biosynthesis is regu lated and relates this information to knowledge of jasmonate modulated gene expression.