Speaker — Isabel Molina, Associate Professor in the Department of Biology and Environmental Science at Algoma University in Ontario, Canada, and Tier II Canada Research Chair in Plant Lipid Metabolism

Title — Biosynthesis, Structure, and Biological Functions of Plant Lipid Barriers

Abstract — The plant cuticle and suberin are cell wall lipid modifications that play a number of important roles in plant biology, acting as barriers to control the movement of water, gases and solutes as well as to protect plants from biotic and abiotic stresses. Both the cuticle and suberized cell walls are composed of polymers of glycerolipids and waxes. The cuticle covers all aerial primary organs where it establishes a vital interaction interface with the environment. Suberin is present in many internal and external tissues including root endodermis and the periderm of roots, tree bark and tubers.

The use of forward and reverse genetic screens in combination with biochemical analyses, particularly with Arabidopsis, have led to the identification of genes that are required for the biosynthesis as well as for the transcriptional regulation of biosynthesis of extracellular lipid barriers. In our lab, we have focused on HXXXD-motif acyltransferases involved in the incorporation of aromatics into lipid polyesters. These studies will be reviewed.

The functional contributions of the maize cuticle and its components to abiotic and biotic stress responses have been rarely studied so far. Moreover, the biosynthesis and composition on the adult leaf cuticle, agronomically the most important growth phase, are largely unknown. We have explored the developing cuticle of mature maize leaves, and cross-referenced biochemical and transcriptomic data. Our progress in this area will be summarized.

Host — Marna Yandeau-Nelson