How does paraquat function in plants


Paraquat takes effect in the sun, and the green parts of any plant that are exposed to it are wilting. Immediately after spraying paraquat can penetrate the leaves. In the high light and high humidity environment, this absorption rate will accelerate. Formulations are usually added to ensure good drug retention and target leaf humidity of a special adjuvant to improve the absorption rate. If the formulation is not mixed adjuvant, it needs to be mixed in the drug tank. The site of paraquat is chloroplast. Chloroplasts contain photosynthetic systems of green plants that absorb light energy and produce sugars. Paraquat is used as a photosynthetic membrane system known as the photosynthetic system I, which produces free electrons to drive photosynthesis. The free electrons produced by photosynthetic system I react with paraquat ions to produce free radical structure. Oxygen rapidly converted these radicals and produced peroxides in the process. Peroxide has a very high chemical activity, it can attack the membrane of unsaturated fatty acids, quickly open and break down the membrane and tissue. Then paraquat ion / radical reaction process will repeatedly produce more peroxides, until the stop generation of free electrons. In the warm and bright conditions, only a few hours can be seen spraying plant was withered, but in the dark and cold conditions, this process required time may be longer. Then the plant tissue will quickly become dry or chlorosis. Therefore, as long as there is sunlight, oxygen and chlorophyll, paraquat can be rapid onset in a unique way. Cell membrane rupture leading to dehydration of plants, leading to rapid withering of leaves.