A team of scientists from the United States announced that they have
identified the protein in plants responsible for its cellular defense
against excessive light, among other stress factors caused by climate
change.

Published literature states that photosynthesis occurs in the plant cell's
chloroplast. In these chloroplasts, proteins make up the molecular structure
that is responsible for the plant's light absorption to produce necessary
chemical reactions to support the plant's development. Exposure to too much
sunlight causes an overdrive reaction and damages the said proteins. These
damaged proteins have to be evaluated, removed and replaced by the plant.
The scientists' objective was to know more about the plants' ability to
evaluate the healthy and damaged proteins and trigger a protective response,
a process in plants that is yet to be thoroughly investigated by
researchers.

Using engineered cells from the algae Chlamydomonas reinhardtii, scientists
were able to discover that the chloroplast is able to send a signal to
activate the "chloroplast unfolded protein response" (cpUPR). cpUPR is the
plant's protective response that is triggered upon overexposure to light,
and leads to the production of specialized proteins that helps protect and
repair the chloroplast. The finding led to the identification of the gene
MARS1, which stands for Mutant Affected in Retrograde Signaling. It plays a
significant role in turning on the cpUPR. The scientists noted that the
algal cells with defective MARS1 were more vulnerable to chloroplast damage
caused by stress factors, including overexposure to light. Cells with
defective MARS1 were observed to be unable to turn on the cpUPR and die.

The results highlight the significance of cpUPR in plants, as understanding
its process can help future scientists to develop better crop endurance
against harsh climates. Moreover, one of the scientists stated that their
findings can also lead to future studies that aims to the increase the
production of antigen proteins in plants, which are used in the production
of vaccines.

[elifesciences.org]