Research interest

Tolerate or succumb: regulation of plant strategies to survive stresses

Plants compete for water, light and nutrient- their prime source of energy that fuels life on earth. Stress-intolerant plants try to escape stress through the Stress Avoidance Syndrome; a growth response that brings the plant movement away from the stress. In contrast to this strategy, stress tolerant species that grow in hostile environments suppress stress avoidance and rely on stress tolerance traits of leaf morphology and metabolism. Using novel as well as established molecular, physiological and ecological methodologies, I will study the molecular regulation of stress avoidance and stress tolerance responses in contrasting wild plant species.

A novel insight from my group and others is that stress avoidance comes with a cost; it is associated with inhibition of plant defenses against herbivores and pathogens. However, it is unknown if and how this mechanism operates in stress tolerant species that suppress stress avoidance. I propose to study the signaling mechanisms of stress-mediated defense suppression to investigate if different adaptive responses to stress signals lead to different interactions with plant defenses Subsequently, fitness implications of stress tolerance and stress avoidance strategies, and their interaction with plant defense will be determined for in wild species, to verify the general ecological significance of the insights obtained.

By taking an interdisciplinary approach I will unravel novel regulatory pathways of plant adjustments to their constantly changing and often hostile environment. This will help understand and predict ecological distributions of plant species and will foster future crop improvement for hostile environment and defense responses.

Research topic and aims at a Glance

Unraveling the mechanisms of different stress response strategies and their interactions with plant defense will greatly improve our understanding of ecological distributions of plant species. Furthermore, knowledge on how water limitation or excess salt or heavy metals controls plant defense strategies will have major consequences for crop improvement.

Plant performance in nature and agriculture is strongly determined by biotic and abiotic environmental factors. Plants being sessile have developed an incredible plasticity to adjust to adverse changes in their environment. Plants obtain their energy from sunlight and most plant species will adopt either a stress avoidance or stress tolerance strategy when in hostile conditions. Stress avoidance responses include growth accelerations to escape from stress cast by neighboring vegetation, into optimal conditions. Both at the ecological, physiological and molecular-genetic level, this response is currently under intensive study. An important recent insight is that plant defenses against herbivorous insects and pathogens are severely inhibited upon induction of stress avoidance.

Interestingly, the molecular regulation of traits that determine stress tolerance, i.e. physiological adaptations that optimize photosynthesis and suppress stress avoidance responses, has not been studied at all. Furthermore, since stress tolerant plants prevent stress avoidance responses I hypothesize that stress tolerant plants do not show severe suppression of defenses against herbivores and pathogens upon stress signaling.

Project Objectives

I aim to unravel the regulatory signaling pathways that determine how opposite adaptive ecological strategies can be activated by different wild plant species in response to stress cues.

I aim to identify:

• • The differential signal transduction mechanisms that underpin stress avoidance and stress tolerance.

  • How stress signals suppress plant defenses against herbivores and pathogens and how this differs between stress-avoiding and stress-tolerating species