The role of the FEI Pathway in Regulating Cell Wall Synthesis

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

Non-technical summary: Plant cell walls are diverse and highly dynamic structures that respond to developmental and environmental cues. They are a primary source of building materials, paper, biofuels, cotton, and many other useful products and also plays a crucial role in the growth and development of plants. Despite their importance both from a practical and fundamental point of view, the signaling pathways regulating the function and assembly of plant cell walls are just beginning to be understood. This project seeks to gain fundamental knowledge regarding how plants regulate the synthesis of their cell walls, which should ultimately help improve the diverse products derived from them and will provide insight into basic aspects of plant growth and development. In addition to providing interdisciplinary training opportunities for undergraduate and graduate students, this project will work with programs designed to increase the representation of minorities in the sciences and with several outreach programs designed to increase the public understanding of plant science. Technical Description of the Project: Previous studies identified a pair of transmembrane protein kinases, called FEI1 and FEI2, that play a role in regulating the biosynthesis of cellulose, which is a critical component of the plant cell wall and acts as the primary load-bearing element. These kinases define a novel signaling pathway that includes a non-canonical role for 1-aminocyclopropane-1-carboxylic acid (ACC), a molecule previously thought to act only as a precursor in the biosynthesis of the phytohormone ethylene. A series of experiments to further characterize the FEI signaling pathway and its role in regulating cell wall function will be pursued. The mechanism by which the FEI pathway regulates cellulose biosynthesis will be explored (Aim 1). The signaling role of ACC and other potential ACC-derivatives in regulating wall synthesis will be examined (Aim 2). Other components involved in this FEI pathway will be identified and characterized, including SHOU4, a protein that appears to act in the FEI pathway and which is likely associated with the cytoskeleton (Aim 3). These studies will answer fundamental questions regarding how this pathway regulates the production of cellulose and how it interacts with other elements to regulate cell wall synthesis. Further, the FEIs are belong to a group of kinases call the receptor-like kinase, which are one of the largest families of genes in plants; the function of only a handful of RLKs are known, and thus these findings will shed light on a poorly understood class of plant signaling elements. Finally, these studies should help elucidate a role for ACC in plant signaling and may uncover important roles for a novel signaling compound in plants.