Plants Sunburn

Photosynthesis is the process by which plants make glucose for energy. In order for photosynthesis to occur, plants first take in light energy to power the light reactions. The light reactions are used to convert light energy into chemical energy that can be used in the Calvin cycle to form G3P. In the light reactions, water is taken into thylakoids and broken apart in photosystem II. It is broken into 2 H+ molecules and one O molecule. The oxygen molecule reacts with photosystem II until another oxygen molecule is created from the breakdown of water so the two oxygen molecules can then form O2, a more stable form of oxygen. The process also creates a modified oxygen molecule called the reactive oxygen species (ROS).

Since the beginning of photosynthesis, plants have had to deal with sun damage. Photosynthesis evolved over 3.5 billion years ago. Researchers have recently found the optimal mechanism plants use to heal what would be equivalent to a bad sunburn. In the article, one of the researchers says that the production of ROS cannot be avoided, it can only be minimized. It can also be a larger problem for plants when they are in unfavorable environmental conditions, like too much heat, too much light, or insufficient nutrition. In AP Biology, we learned that when there is too much heat, most plants close their stomata to slow the evaporation of water. This also lessens the amount of light that enters which slows the process of photosynthesis. In their study, the focus was on a specialized system of photosynthetic membrane inside the chloroplast. Remember that inside the chloroplast, the light reactions occur by the movement of electrons from photosystem II to the electron transport chain, then to photosystem I, and finally the ATP Synthase molecule makes ATP. On the photosystems, there are chlorophyll which take in the light energy needed to power each of the photosystems. It was previously known that the plants machines make the repairs on their nanomachines that are targeted by oxidative damage in multiple steps and each steps occurrence is dependent on the success of the step before it. The researchers in this study discovered that the separating of different repair proteins to different membrane regions is what creates the required order of steps. The folding of the membrane guarantees this compartmentalization.

The findings from this research could help make plants tailored to geographic regions and climate zones, which would make them easier to grow in places with unfavorable environmental conditions. CAM plants are already specialized plants for high heat. They open their stomata during the night, when there is less heat, and take in the CO2. Then they close the stomata at night and the CO2 that was taken in at night is fixed by rubisco in the Calvin cycle. With the new research, scientists may be able to create mutated plants that can handle other types of climates as well.

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Biology Teacher

This entry was written by Priya J. and tagged . Bookmark the permalink.

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