Study reveals key proteins involved in the regulation of photosynthesis
Researchers from the Max Planck Institute of Molecular Plant Physiology and the College of Natural Science at Michigan State University have uncovered the importance of two major proteins, called VCCN1 and KEA3, in the regulation of photosynthesis. They carried out a series of experiments on the model plant—Arabidopsis thaliana—by changing light conditions, to mimic the natural conditions involving light and shadow.
Why does this story matter?
There is a limited understanding of the mechanism by which plants adapt to varying light conditions. There is a possibility that plants that grow well in laboratories might not perform as well when cultured in the field. Plants are generally grown under stable and uniform light conditions in laboratories or greenhouses for research purposes, and this is different from the natural conditions.
Photosynthesis forms the basis of the food chain
Photosynthesis is a highly regulated, multi-step biochemical process that forms the basis of plant growth. During the process, energy from sunlight is harvested to drive the conversion of carbon dioxide and water to ultimately produce oxygen and carbohydrates (glucose), which is the most basic food resource. Plants optimize the photosynthetic process according to the change in lighting conditions.
Too much light is damaging to plants as well
Plants have chlorophyll, a green-colored pigment in their leaves that captures light, similar to the retina in our eye. But too much light can be damaging for plants as well and they have to adapt to the change in environmental conditions.
VCCN1 and KEA3 are ion-transport proteins
The ion-transport proteins VCCN1 and KEA3 play a significant role in the dynamic control of photosynthesis. It has been known that VCCN1 activates sun protection if the light is too strong. When the light intensity decreases, KEA3 breaks down this sun protection so that the plant can absorb the required light. But these proteins have not been studied under natural light conditions so far.
The activity of the proteins depended on the light conditions
In the study, a new approach to determine photosynthesis was used along with the targeted use of gene knockouts i.e. the genes responsible for VCCN1 and KEA3 proteins were removed. Several conditions including static, fluctuating, and natural light, were experimented with. It was seen that the activity of VCCN1 and KEA3 depended on the light conditions in which the plants were raised.
The amount and frequency of light fluctuations had an impact
The study revealed that both the amount of light a plant receives and the frequency of light fluctuations exhibited a strong impact on the function of the two proteins. The light-protective function of VCCN1 was only relevant in plants previously grown under low light. KEA3, which eliminates protection, was active even when the plants were grown under conditions with elevated light intensities.
Zeaxanthin, an orange pigment, also has a protective function
Sun protection is also dependent on the degree of light fluctuations that the plants are exposed to, noted the study. When there is a significant change in light conditions, plants produce zeaxanthin, an orange pigment, which is also involved in sun protection.
Such research aid in the improvement of crop yields
"Our study shows that we should not look separately at the effect of growth light and the rapid responses to light fluctuations," said Thekla von Bismarck, lead author. "The integration of multiple time scales and metabolic levels in an increasingly complex manner will be a major future challenge for crop research. This will provide key ideas to improve crop yields in the field."
