HCS Spring 2016 Seminar Series
“Defining the biochemical physiology of plant stress responses”.
Abstract: Plants are regularly exposed to a wide variety of traumatic biotic and abiotic stresses, and plant survival depends on the ability to sense and respond to these external stimuli. In order to be successful, stress responses must be rapid and lead to changes in gene expression and plant morphology resulting in adaptive growth. Changes in membrane composition, lipid signaling, and hormone transport and metabolism all take place within seconds to minutes of exposure to stress responses and link stress perception to adaptive growth responses. Individual stresses can therefore be considered to generate distinct metabolic “stress fingerprints.” To define these “stress fingerprints” and determine their role in regulating adaptive stress responses, our laboratory has developed a biochemical/ metabolomic toolbox allowing the high-throughput profiling of phytohormones and related metabolites, membrane phospholipids, terpenes and sterols, and other key metabolites involved in stress responses. We have used these tools in conjunction with whole-plant and cellular physiological stress-response assays to investigate plant responses to both abiotic and biotic stresses. Our results indicate that, in the case of both abiotic and biotic stress responses, interactions between the transport and metabolism of the phytohormone auxin (indole-3-acetic acid) and the lipid signaling molecule phosphatidic acid (PA) are essential for adaptive growth responses. Defining the “stress fingerprints” generated by individual stimuli and the downstream targets of these metabolic changes will allow the development of targeted stress mitigation strategies involving either metabolic/genetic engineering, “in field” treatment with growth regulators, or a combination of these approaches.