Hanna Hõrak, associate professor of molecular plant physiology

Molecular Plant Physiology Lab

Research:

In the Molecular Plant Physiology lab, we use genetics and molecular biology to study how plants perceive and respond to stress signals they receive from the environment. We aim to understand, how stomatal numbers in leaves are determined during plant development and how environmental conditions affect this process. We want to know, how stomata are made and how stomatal numbers and patterning affect plant physiology and stress responses. As stomatal pores in leaves are the gate of entry for carbon dioxide used in photosynthesis, but also serve as the exit door for water, stomatal numbers and responsiveness are key determinants of plant survival and yield. Our major research goal is to discover trait combinations of stomatal patterning, density and responsiveness that enable to increase plant water use efficiency (and thus resistance to drought) without major negative impacts on photosynthesis and yield.

We use Arabidopsis (thale cress, Arabidopsis thaliana) as a model plant for our research in the lab, but also collaborate with researchers from the Centre of Estonian Rural Research and Knowledge (METK) to study agricultural plants, such as tomato, potato, and cereals.

Stomata and epidermal cells in the bottom cell layer of an Arabidopsis leaf. Photo: Hanna Hõrak

Arabidopsis leaves marked for a stomatal development experiment. Photo: Kaspar Koolmeister

Possible topics for student theses (topic will be specified together with the student to account for their interests and wishes)

The effects of different stomatal numbers, apertures and patterning on plant water use efficiency and productivity
The role of phytohormone abscisic acid in stomatal development
The effects of environmental conditions on stomatal development

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Publications

Associate Professor: Hanna Hõrak (hanna.horak@ut.ee)

Researcher: Pirko Jalakas (pirko.jalakas@ut.ee)

PhD students:

Ingmar Tulva (Research Fellow, ingmar.tulva@ut.ee)

Elena Ivandi (Junior Researcher, elena.ivandi@ut.ee, collaboration with Model and Crop Plant Ecophysiology group and METK)

Kaspar Koolmeister (collaboration with Plant Signal Research Group)

Kajal Samantara (collaboration with Model and Crop Plant Ecophysiology group)

Students:

Karl Mäll

Marlin Poogen