Dr. ir. H.A.C.F. (Melissa) Leeggangers

Dr. ir. H.A.C.F. (Melissa) Leeggangers

Researcher
Plant Stress Resilience
h.a.c.f.leeggangers@uu.nl

Within the Plant Stress Resilience (PSR) group at UU Plants, I work on two different projects related to the environmental stress flooding. Pro-longed heavy rain showers oversaturate the soil first, but can eventually lead to partial or complete submergence of the plant. Therefore flooding of the roots (waterlogging) occurs first.

 

Systemic signaling during waterlogging in Arabidopsis thaliana

During waterlogging, the water forms a barrier in which it blocks outward diffusion of the gaseous phytohormone ethylene in the roots. This rise of ethylene levels together with the drop in oxygen leads to a cascade of events triggering an acclimation response to the stressful environment. I am currently interested in what root derived signals travel to the shoot and how the shoot responds to these signals. Understanding this process will be beneficial for the development of flooding resilient plants. 

One of the candidates being investigated in Arabidopsis is the ethylene pre-cursor 1-Aminocyclopropane 1-carboxylic acid (ACC). In the early seventies was shown that during waterlogging ACC is able to travel to the shoot where it induces downward movement of the leaves, known as epinasty. It is unknown whether a similar systemic signaling mechanism exists in Arabidopsis. 

 

Dormancy as a predictive indicator for flooding resilience

Another aspect of flooding resilience that I am investigating is whether seed hibernation depth (dormancy) can be used as a predictive indicator for flooding resilience. With the current climate changes it would be beneficial to develop these predictive indicators during the early stages of development to speed up the breeding process. This research idea has been recently awarded with an NWO ENW-XS grant to start exploring. 

Project summary can be found at: https://www.nwo.nl/en/news/twenty-eight-promising-research-projects-launched-within-open-competition-enw-xs