GPX7 Mediates Iron Involved In The Light Of Redox Process Mechanism Research In Arabidopsis Thaliana

Light is an important energy source for photosynthesis,the plant covert light into chemical energy stored in the body through photosynthesis,but excessive light will inhibit photosynthesis and produce more reactive oxygen species(ROS)in plant.It causes the oxidative damage leading to the occurrence of light inhibition.The chloroplast is the important place of photosynthesis and the production of ROS.Iron is involved in chlorophyll synthesis and catalytic sites of oxidoreductase.Under iron deficiency,plant cells seriously affected many important physiological processes such as photosynthesis,respiration,reactive oxygen metabolism and cellular redox state,which may affect the plant growth.In order to avoid the occurrence of photo inhibition,plants form a clear mechanism such as glutathione,ascorbic acid and peroxidase(POD)and catalase(CAT).But we study the glutathione peroxides(GPXs)first found in the animal,it can scavenge ROS.GPX7 scavenging the ROS in plants lacks deep research.Therefore,GPX7 mediating the reduction process mechanism of light oxidation is unclear.These issues deserve our further study.Early results showed that gpx7 mutant appeared light bleaching phenomenon.Therefore,we used the gpx7 mutant of Arabidopsis thaliana as material for analysis.Through the NBT and DAB staining in high light,the deletion of GPX7 made the content of ROS increase.We found some genes which related to photosynthetic electron transfer and redox.Expression of these genes changed.Meanwhile,the gpx7 mutant was sensitive in iron.The obvious phenotype was found in the deficiency of iron and induced the expression of GPX7.Through the NBT and DAB staining,gpx7 mutant produced more H2O2 in the deficiency of iron.We found a lot of genes from the chip of GPX7,and the iron played an important role in their function.The expression of these genes was changed in the deficiency of iron.The above results indicate that GPX7 has the function of scavenging the ROS in plants.It is involved in light regulation of redox process.Under iron deficiency,the ROS content was increased,and caused the change of redox state in chloroplast.