Regulation of Lipid Droplet Accumulation in Plant Tissues

Date

Friday 15 September 2017

Time

11:45- 12:45 (AEST – Canberra Brisbane Armidale Werribee); 11:15 (ACST – Adelaide); 9:45 (AWST – Perth)

Venues

CSIRO: Black Mountain – Stringybark Theatre, Synergy; Adelaide Waite – B101-FG-SmallWICWest; Brisbane QBP – Level 3 South telepresence room (3.323); Armidale – B55-FG-R00-Small; Perth Floreat – B1b Boardroom; Werribee (Melbourne) – Peacock Room

Speaker

Dr. Kent Chapman Regents Professor and Co-Director, Biodisovery Institute, University of North Texas USA

Synopsis

Of the cellular processes that participate in energy conversion and storage, perhaps the least well understood are the mechanisms for packaging reduced lipids into structures compatible with the aqueous environment of the cell. In fact, even the inventory of proteins that participate in the compartmentalization of storage lipids in plant tissues is far from complete. While oleosins are well known proteins associated with lipid droplets in seeds and pollen, most plant tissues do not express oleosin genes despite their ability to produce LDs. Our overarching goal is to understand the biochemical and cellular processes important for compartmentalization of storage lipids in plant tissues. Toward this end, we have taken two different approaches to identify new players involved in LD biology in plant cells. First, we have looked to potential homologues of proteins in other organisms that influence LD formation and neutral lipid accumulation/turnover, such as CGI-58, SEIPIN FSP27 and FIT2. These proteins influence LD accumulation in different ways in plant cells. CGI-58 interacts with the peroxisomal transporter for fatty acid uptake (PXA1) to facilitate lipid turnover and the production of signaling lipids. SEIPINs in plants have been elaborated relative to yeast and humans and are present as distinct isoforms that influence both LD abundance and size. And while obvious homologues of FSP27 and FIT2 are not present in plants, the ectopic expression of mouse homologues result in the fusion or formation of numerous large LDs in leaf cells. In the second approach, a proteomics-oriented analysis of LDs from non-seed tissues uncovered a novel class of LD-associated proteins (LDAPs) and further investigation has revealed additional LDAP-interacting proteins. The LDAPs target specifically to LDs in plant cells, and different isoforms respond to environmental stressors to influence LD dynamics or have functions in LD stabilization and TAG mobilization during seed germination. Furthermore, manipulation of the expression of the LDAPs generally affects LD prevalence in plant cells. Progress in these areas will be discussed with an emphasis toward how this information might be employed to manipulate neutral lipid content and increase the energy density of plant tissues.

Biography

Dr.  Kent Chapman completed a B.A. degree in biology in 1986 from Lycoming College in Williamsport, PA. He then traveled Tempe, AZ, where he earned a Ph.D. degree in botany (plant cell biology) at Arizona State University under the supervision of Richard N. Trelease for studies on peroxisome membrane lipids.  After completing his doctoral degree, Chapman was awarded a 2-year NSF postdoctoral fellowship to study plant biochemistry with Thomas S. Moore, Jr., at Louisiana State University in Baton Rouge, LA.  In 1993, he accepted a position as a tenure-track, Assistant Professor of Biochemistry at the University of North Texas (UNT) in Denton. During the last 20+ years, Chapman has developed an internationally-recognized research program in plant biochemistry and cell biology, specifically in the area of plant lipid metabolism. He currently serves as Co- Director of the BioDiscovery Institute at the University of North Texas.

This is a public seminar.

A visitor pass is required for non-CSIRO attendees attending The Stringybark Synergy Theatre- these are available at Synergy Reception.