Cross-talk between light acclimation and defence reactions in plants

We aim to resolve light-dependent regulatory networks underlying metabolic adjustments and stress resistance in plants. New insights will be applied to domestic farming techniques in order to improve the availability of healthy, tasty, and nutritional crops with high post-harvest quality and yield.

Background

As the global population becomes more urban, nutritional security will depend on the availability of stress-resistant crops with high post-harvest quality and yield. Plant resistance to environmental stress relies on molecular mechanisms that can sense, signal, and respond to external cues. However, the specific mechanisms that execute these defensive measures in response to different stress stimuli are not well understood. During evolution, plants developed a remarkable diversity of species-specific chemical defenses to protect photosynthetic tissues against light-induced damage or to prevent pathogens and pests from destroying host plant tissues. Determining how the perception of stress proceeds through regulatory networks, via signaling, and provokes the appropriate developmental, physiological, and metabolic adjustments remains a major biological question to be solved.

Research

1. Regulatory networks underlying stress resistance in plants.
We study protein phosphatase 2A (PP2A), which forms a hub of signal transduction in plant cells and enables the plant to establish light acclimation and pathogen resistance. In this, we work to elucidate the biochemical and physiological mechanisms that enable the integration of different environmental cues by phosphatase-kinase-cascades involving PP2A. We focus on identifying the target enzymes of this phosphatase and characterizing the post-translational modifications and molecular activity changes elicited by PP2A in cellular signalling pathways.


2. Trans-methylation reactions and glucosinolate biosynthesis in cruciferous plants.
Trans-methylation reactions are vital in basic metabolism, epigenetic regulation, and the biosynthesis of secondary metabolites. We aim to elucidate post-translational regulation of the “activated methyl cycle” and its critical role in determining methyl utilization in stress-exposed plants. More specifically, we examine how protein phosphatase 2A (PP2A) and light regulate the activated methyl cycle and the associated biosynthesis of glucosinolates, which are bitter-flavored defense compounds that affect the taste of cruciferous crops.

Significance

The biosynthetic machineries of plants are highly responsive to light and therefore, their metabolite profiles can be manipulated by changes in the intensity and spectral quality of light. The overall aim of our research is to understand the light-dependent regulatory mechanisms underlying metabolic adjustments and stress resistance in plants, and we are especially interested in the regulation of organelle signaling and the formation of herbivory-deterring secondary metabolites.  Because plant-derived natural compounds can significantly impact the taste, healthiness, and durability of crops these studies are relevant to food technology, agriculture, and even medicine. In addition to expanding the basic understanding of plant stress biology, new information could enhance food development and the efficiency of urban farming.