Kaisa Kajala
Environmental signaling of plant cell types
Multicellular life depends on multiple cell types working together in an intricately coordinated manner. Each cell type plays a role for the fitness of the plant. These roles are fulfilled by specific developmental, structural, and metabolic cell traits, regulated by specific gene regulatory networks. For example, exodermis is a protective cell type in the root, and exodermis provides it protection through differentiation steps that lead to deposition of lignin and/or suberin in the cell wall. The regulatory networks controlling these differentiation steps dynamically integrate positional, developmental, and environmental signals. These cell type-specific networks have always sparked my curiosity, and the key questions my group focuses on are:
How do cells know who they are? In other words, what are the signaling networks underlying cell type identity?
How did various cell types evolve? How did the signaling and regulatory networks of various cell types change across the evolution of (flowering) plants?
How do cell types process environmental signals? Firstly: how do cell type traits respond to environment? And secondly: how are the environmental signals integrated into the developmental regulatory networks?
My group uses a few different cell types and environmental cues to study these topics. The approaches we use include high-throughput sequencing, histology, developmental biology, genetics, and physiology with a diversity of plants species. Current projects focus on exodermis, a protective barrier cell type found in roots and its response to drought; stem cell types in response to far red light; and cell types of Arabidopsis leaf in response to touch.