After a rapid increase in light intensity, photosynthesis needs a few minutes to reach a new steady state. In most plants, the increase in photosynthesis can be limited by different processes such as enzyme activation and slow stomatal movements, which under a fluctuating light environment results in reduced carbon gain. Using leaf gas exchange, the photosynthesis response to step-changes in light intensity has been characterized in several species, but is a lengthy process that also has a low experimental throughput. Large scale and remote measurement of photosynthesis induction would enable the selection of cultivars with traits of interest (e.g. GWAS) and monitoring of their responses at different growth stages. A candidate technique to achieve this is to use chlorophyll a fluorescence, a proxy for photosynthesis that can be performed remotely. However, the bottleneck of this technique is the need for a saturating flash of light (>10000 µmol m-2 s-1) over the measuring area, reducing its applicability to only small scale experiments (<100 cm2). Therefore, previous works at HPP have focused on finding a new interpretation of the chlorophyll a fluorescence signal without having to do a saturating flash. Preliminary results at the leaf level have shown that there is a strong correlation between the temporal response of chlorophyll a fluorescence and photosynthesis induction, but further work is needed to validate them.
Combining leaf gas exchange and chlorophyll a fluorescence measurements, you will refine the current methods/protocols developed previously and contribute to the improvement of plant phenotyping and monitoring tools. You will develop and/or perform novel ways to analyse the data that you have obtained, in order to extract useful parameters. The research will be performed on tomatoes.
- Performing climate chamber experiments
- Gas exchange
- Chlorophyll a fluorescence measurement
- Data analysis
Interested in doing a BSc or MSc thesis at HPP? Please contact the HPP student coordinator Katharina Hanika.