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We know that plants require light in order to survive, but did you know there is such a thing as too much light in plants? Researchers at UCSF have recently discovered a protein in plant cells that allows plants to defend themselves from damage due to excess light, as well as other environmental stressors.
Plants are a vital key in surviving on Earth, as they function as energy sources for many living things, like us humans, as well as animals. Through the process of photosynthesis, which takes place in the chloroplasts of the cell, plant cells are able to use sunlight, a source of energy, to convert carbon dioxide into sugars and oxygen. Sugars are beneficial to living things as a source of energy, and oxygen is crucial for our atmosphere, especially if we want to breathe. The article mentions the process of photosynthesis, which ties into what we just learned in class.
As our climate grows to be more harsh, we are exploring what goes on in a plant cell as harsh conditions, such as excessive light, affect a plant, and what do the cells within it do in order to protect themselves. Researchers at UCSF (University of California, San Francisco) have figured out how the protective response is triggered. They began their testing by genetically engineering a type of algae called Chlamydomonas reinhardtii. If the chloroplast proteins were damaged, the plant would be caused to form fluorescent cells. Using the fluorescence to their advantage, they were able to find the cells that were unable to trigger the cpUPR (chloroplast unfolded protein response: the protective mechanism plant cells have), and look for mutants in those cells.
After finding the cells that were unable to fluoresce, they were able to find the gene that activates the cpUPR, which is called Mutant Affected in Retrograde Signaling, or MARS1. When the cells in MARS1 are mutated, they become more sensitive to excessive light, and are in turn, unable to activate the cpUPR, and eventually die. However, upon restoring the cells in the MARS1, the cpUPR was able to turn on, and the chloroplast proteins were able to be protected from excess light once again. The knowledge of this protective mechanism is useful, as according to Peter Walter of UCSF, as he says in the article “this response could be harnessed in agriculture to enhance crop endurance to harsh climates, or to increase the production of proteins in plants called antigens that are commonly used in vaccines.”
This is relevant to our class as we just learned about in class, as we just recently learned about the inner workings of a plant cell. We learned that plant cells specifically contain chloroplasts, which drive the process of photosynthesis, which is earlier mentioned. As photosynthesis is crucial to life as it produces oxygen, which we breathe in. The oxygen that we breathe in then becomes a reactant in the equation of cellular respiration, which is essential for us to produce ATP, the source of energy in our cells, as we learned in class this past week. If cells did not have the protective mechanism to protect from environmental stressors, then plants would not be able to survive in the face of harsher conditions, and the death of plants would be detrimental to life as a whole.