Membrane Lipid Remodeling and Its Impact on Critical Stages of Plant Development

February 24, 2025 @ 12:15 pm to 01:15 pm

Jitao Zou, Penn State University

108 Wartik Laboratory
University Park

Abstract
Phosphatidylcholine (PC), one of the major phospholipids in eukaryotic cell membranes, is neither stationary in its location nor static in its fatty acyl composition. It undergoes constant remodeling mediated by various classes of phospholipid hydrolases, and a ubiquitous lipid turnover process known as the Lands Cycle. The Lands Cycle consists of two main enzymatic components: (i) a phospholipase that deacylates PC to form lysophosphatidylcholine (LPC), and (ii) a lysophosphatidylcholine acyltransferase (LPCAT) that facilitates the reacylation of LPC back to PC. Editing the fatty acid composition of PC to match the profiles required for specific cellular differentiation and signaling events is considered a primary function of the Lands Cycle. However, the Lands Cycle also operates in organisms like yeast, where the fatty acid composition of membrane lipids is simpler, and the asymmetric distribution of fatty acids in PC is thought to be largely dictated by the de novo (Kennedy) biosynthesis pathway. We have investigated the role of LPCAT in PC remodeling in Arabidopsis. Our findings indicate that a disrupted balance in the Lands Cycle, due to LPCAT deficiencies, not only accelerates PC turnover but also triggers a compensatory response in de novo PC synthesis. Additionally, we uncovered developmental phenotypes in the lpcat mutant that cannot be easily explained by lipid compositional changes alone. These phenotypes highlight the intricate role of lipid remodeling in membrane dynamics, plant growth, and development, which will be further discussed.

About the Speaker
Dr. Jitao Zou is a Research Professor in the Plant Science Department at the College of Agricultural Sciences, The Pennsylvania State University. He earned his Ph.D. from the Institute of Botany at the Chinese Academy of Sciences and completed his postdoctoral training at Yale University. Before joining Penn State in May 2024, Dr. Zou served as a Principal Research Officer with the National Research Council Canada, where his work focused on plant lipid metabolism and abiotic stress research.

Contact

Teh-hui Kao
txk3@psu.edu