New work led by Carnegie's Petra Redekop, Emanuel Sanz-Luque, and Arthur Grossman explores how plants protect themselves from self- harm. Our understanding of one of the most important biochemical processes on Earth has been improved by their findings.
The sun's energy can be converted into chemical energy by plants, algae, and certainbacteria. It is responsible for the oxygen-rich nature of our atmosphere.
Life as we know it couldn't exist without photosynthesis.
The process is done in two phases. In the first, light is absorbed and used to synthesise energy molecule with water and oxygen as a result. The second stage uses carbon dioxide from the air to make sugar.
Plants are exposed to the sun for photosynthesis. Access to sunlight can be affected by a number of factors, including weather, clouds, and canopy cover.
How do plants deal with variability?
"It's necessary for plants and algae to be able to harvest sufficient light when they're in the shade and to diminish the amount of absorbed energy when light conditions are intense, such as at high noon," said Redekop.
Plants and algae can be damaged by highly reactive oxygen molecule if they aren't taken care of. Plants and algae have evolved ways to quickly quench the excess light energy before it can cause harm.
Redkop, Sanz-Luque, and Grossman, along with colleagues from the University of Grenoble Alpes, characterized the genes that are involved in regulating the expression of the protective proteins in the Chlamydomonas.
The genes are activated by an integrated series of signals with built-in redundancies that help plants and algae to maximize their environmental responses.
A suite of conditions that triggered the genes' activation was revealed by the team's work.
The researchers found that the expression of genes in the dark. This is proof that plants and algae are prepared for the early morning light.
Blue light increases from dawn to midday and decreases from noon to sunset, which causes the activation of the genes. This shows the effectiveness of the system regulating photo protection.
The genes are activated by the presence of UV-B radiation, which is not blocked by cloud cover, allowing algae and plants to track the time of day and prepare for changes in light availability.
The availability of carbon dioxide regulated one of the photo protection genes. Further analysis is required to understand the regulatory network.
This set of regulatory features form a protective cloak that dampens the risk posed by excess light in a rapidly changing environment. Plants and algae have evolved to maintain productivity and minimize harm.More information: Petra Redekop et al, Transcriptional regulation of photoprotection in dark-to-light transition—More than just a matter of excess light energy, Science Advances (2022). DOI: 10.1126/sciadv.abn1832 Journal information: Science Advances