Soil pollution, as one of the toughest environmental problems, has arisen seriously due to sewage irrigation and industrial mining. Heavy metal accumulation has been an important factor resulting in soil pollution, and cadmium pollution has become a main problem. Statistics shows that cadmium pollution has become quite severe in a large range of China, especially in the southeast.
Cadmium is extremely easy to be absorbed by plant roots and enriches in seeds. Then, Cadmium-enriched food brings this element into human body, bringing great damage to human liver, kidney, and even the nervous system. Many people suffered from the infamous incident "Itai-Itai Disease" in Japan. Being shocked and impressed with the powerful invasive ability of these cruel parasites, we feel urged to relieve this situation with our own effort.
OsNramp5 is a channel protein for the absorption of cadmium and manganese ions in rice root cells, and is responsible for transporting them to the above-ground parts[2].According to previous research, more Cd2+ would accumulate in root tips and lateral root primordia when OsNramp5 was overexpressed in the rice, indicating that OsNramp5 is related to Cd2+ absorption[3].Researchers have knocked out OsNramp5 in rice to reduce cadmium accumulation. However, the yield was also reduced in the absence of Mn2+ .
Our project aims to solve this problem through directed evolution to obtain OsNramp5 which transports less content of Cd2+ but normal that of Mn2+ .
