Project Details
Projekt
Investigation of cell polarity mechanisms connected to cell fate and pattern formation in Arabidopsis vascular and stomatal development
Applicant
Dr. Eva-Sophie Wallner
Subject Area
Plant Cell and Developmental Biology
Term
from 2019 to 2022
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 438457603
Plants are complex organisms with many specialized tissues. Important origins of cellular diversity are asymmetrically dividing stem cells that produce daughter cells of different fate. To orient and execute asymmetric divisions in plant cell lineages, cell polarity is established by polar localization of molecular regulators whose modes of action are still only poorly understood. Here I will investigate how cell polarity proteins 1) regulate cell division and fate within distinct cell lineages, 2) are regulated in a spatio-temporal manner during fate transitions and 3) organize subdomains of the plasma membrane proteome/protein composition. To address these long-standing issues, I will compare polarity mechanisms used in the development of two distinct, but functionally co-dependent and essential plant structures: stomata that enable gas exchange with the environment and the vasculature that distributes water, nutrients and sugars throughout the plant. My preliminary data suggests that BREAKING ASYMMETRY IN THE STOMATAL LINEAGE (BASL), a polarity protein and fundamental regulator of the stomatal lineage, also regulates vascular cell divisions. Using genetic and histological approaches, I will further investigate the genetic framework of BASL and its interaction with polar localized vascular regulators, such as BREVIS RADIX (BRX). Another important unexplored aspect is the spatio-temporal control of BASL protein levels within specific cell types, and I will use a powerful cell culture system to identify components of BASL’s degradation machinery. My third approach requires pioneering a technique new to developmental plant biology - proximity labeling - to map and compare plasma membrane proteomes of two distinct, polarized subdomains in both stomata and vascular lineages. Using specific polarity markers BASL-BRX and a new protein I identified to localize opposite of the BRX domain (anti-BRX) in combination with a biotin-based proximity labeling approach successfully established in the host lab, puts me in a unique position to determine polarized plasma membrane proteomes. I expect to generate novel insights into cell polarity and fate in general, and to reveal cell-type specific differences between stomatal and vascular development in particular. As stomata and vasculature fundamentally determine plant fitness, identifying common polarity mechanisms regulating development could not only be the starting point of my independent research career but could also help to increase crop yield in the future.
DFG Programme
Research Fellowships
International Connection
Austria, USA
