Measurements of photosynthetic activity of higher plants by the method of Pulse Amplitude Modulation fluorimetry.
The method is used for measurements of various photosynthetic parameters. One of the most popular options is the photosynthetic efficiency. The measurements can be applied for whole leaves or its parts, as well as for suspension of chloroplasts or of microalgae cells.
The method description. Most photosynthetic organisms absorb the energy of light quanta by the unique pigment – chlorophyll. This energy can be used for photosynthesis emitted in fluorescence or dissipated as heat. Any changes in the photosynthesis process will be reflected on the level of chlorophyll a fluorescence. Therefore, an evaluation of the photosynthetic apparatus efficiency is the measurement of fluorescence using a fluorimeter, for example, Mini-PAM (WALZ, Germany). The device can record the fluorescence and emit actinic light triggered. The device is portable, allowing to carry out the work not only in laboratories but also in the field conditions.
The method of PAM-fluorimetry is one of the most high-quality, express and relatively inexpensive methods of the photosynthetic apparatus diagnostics at abiotic (the effect of light, the effect of temperature, water stress), biotic (damage by microorganisms and insects) or anthropogenic stress.
During the school it is planned:
- To analyze the fluorescent parameters of chlorophyll a, measured in the «Bétula» leaves (Birch). Before measurement, the samples will be selected from several places in the Pushchino town.
- To measure the fluorescence parameters of chlorophyll a in leaves «Písum» (Peas). The effect of several stress factors on photosynthesis in the leaves will be studied: growing on saline soil, growing in various light conditions, as well as the effect of photoinhibition. Thus, it will be considered not only the influence of stress factors on photosynthesis, but also long-term and short-term acclimation of the plants to the new conditions.
- Using the spectrophotometric method concentrations of chlorophyll a and chlorophyll b in the mentioned above samples will be measure. This measurements will complement the information on the external impact on the plants.
Depending on the readiness of the participants it is possible to solve all three problems within 4 hours. However, even the solution of one problem is a successful understanding of the material.
Master class leads Zhurikova Elena, PhD student of Institute of Basic Biological Problems, RAS, e-mail address for questions from the participants: zhurikova-alena@yandex.ru