link to homepage

Institute of Bio- and Geosciences

Navigation and service

Mechanistically linking sun-induced chlorophyll fluorescence to leaf physiology

Kelvin T. Acebron

Photosynthesis is a dynamic process by which plants utilize light energy from the sun and convert it to chemical energy for its productivity. Understanding the dynamics of photosynthesis requires techniques that use information from chlorophyll fluorescence emission and leaf gas-exchange to estimate photochemistry and CO2 assimilation, respectively.

My main work mainly involves the use of high-resolution hyperspectral imaging system to retrieve sun-induced fluorescence (as well as other vegetation indices) which can contain both spatial and temporal information throughout the whole plant canopy. By combining this method with active fluorescence measurement (i.e. PAM and LIFT), the rate of electron transport, PSII efficiency and NPQ can be simultaneously estimated and used for the interpretation of passively-retrieved fluorescence signal. Since photochemistry, NPQ and fluorescence are three competing relaxation pathways for absorbed light energy, measuring the rates of these processes simultaneously can provide us insights of the plant function both in vivo and in situ. Initially, I would like to understand the variations in SIF and link the retrieved signal to the functional status of the leaf. Part of the research is to uncouple the strong link between SIF and absorbed light energy by detecting changes in steady-state of photosynthesis measured using active fluorescence. To do this, I am using a simple rosette canopy of Arabidopsis plants having specific mutations (i.e. in NPQ capacity, state transition, stomatal regulation, Rubisco activity, and chlorophyll breakdown, starch synthesis) in order to understand how the fluorescence intensity and yield changes throughout the diurnal course of the day. I also aim to measure SIF in economically-important crops such as rice in order to understand the plant function of different varieties both at stressed and non-stressed condition.