Doctoral defence: Chung-Yueh Yeh "Characterization of MPK and HT1 kinases in CO2-induced stomatal movements"

On 17 May at 14:15, Chung-Yueh Yeh will defend his doctoral thesis in biomedical technology "Characterization of MPK and HT1 kinases in CO2-induced stomatal movements" ("MPK ja HT1 kinaaside iseloomustamine CO2-toimelises õhulõhede liikumistes").

Supervisors:
Professor Hannes Kollist, University of Tartu
Associate Professor Yuh-Shuh Wang, University of Tartu

Opponent:
Professor Taishi Umezawa, Tokyo University of Agriculture and Technology
Koganei, Japan 

Summary:
Plants are converting atmospheric carbon dioxide (CO2) into energy rich organic compounds by photosynthesis and this process releases oxygen for human beings and other heterotrophs. Therefore, understanding how plants work in the changing environmental conditions is important.

Guard cells, which form stomatal pores in plant leaves, regulate plant gas exchange. Plants need to maintain a balance between CO2 uptake for photosynthesis and releasing water vapor through the stomatal pores. This balance is crucial for plant survival in changing environmental conditions. Elevated CO2 triggers stomatal closure and this affects leaf temperature, water-use efficiency, plant growth and crop yield. The molecular mechanisms defining how plants sense CO2 in guard cells and transmit this signal to regulate stomatal aperture were not fully understood. In this thesis, we proposed a model for stomatal CO2-sensing. We demonstrated that interaction between mitogen-activated protein kinases (MPKs) MPK4/12 and HIGH LEAF TEMPERATURE 1(HT1) form the long-sought primary stomatal CO2/bicarbonate sensor in guard cells. Furthermore, we demonstrated that the CO2-sensing mechanism is independent of the MPK12 kinase activity. The findings presented in this thesis can be further used to design crops with modulated water use efficiency in the rising atmospheric CO2 environment.

Defence can be followed in Zoom: https://ut-ee.zoom.us/j/9530588152?pwd=ZzgzMjY4YytzUkZ5aVRCd2pOdVNQQT09 (meeting ID: 953 058 8152, passcode: kaitsmine).

Andres Tennus

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