The Response Mechanism Of Mitochondria In Tetraploid Robinia Pseudoacacia Under Salt Stress

Mitochondria is the main place of plant respiration, provide energy in order to maintain the normal life activities of the body, the electron transport chain on its inner membrane is the major site of the reactive oxygen species. Under normally circumstances, the reactive oxygen species generation and scavenging is balanced within mitochondria, but the balance will be destroyed after salt stress and excessive reactive oxygen species can destroy the structure of mitochondria, as a result that the normal operation of it’s function was affected. In the study, we used tetraploid Robinia pseudoacacia mitochondria as materials to analyze the changes in ultramicrostructure and biochemical indicators as well as the differential proteomic expression under different salt stresses. In order to further explain the mechanism of salt tolerance of mitochondria.With the increase of salt concentration, the mitochondria of diploid Robinia pseudoacacia mostly began deformed and appeared hollow, as well as the ambiguous crista structure were observed. Nevertheless, only small number of mitochondria in tetraploid Robinia pseudoacacia was damaged, while most of them showed clearly in membrane and complete structure.Under salt stress, H2O2and MDA content in diploid and tetraploid Robinia pseudoacacia mitochondria were increased significantly. The relevant antioxidant enzymes activity in tetraploid was generally higher than that of diploid, which can detoxify the excess reactive oxygen species more quickly during salt stress, in order to maintain the balance of reactive oxygen species production and scavenging, thus enhancing the ability of mitochondria resistance to salt stress.We detected the differential expression of mitochondria protein in diploid and tetraploid Robinia pseudoacacia using two-dimensional electrophoresis technology. Diploid Robinia pseudoacacia mitochondria were detected125differential protein spots, of which45protein spots were up-regulated,59protein spots were down-regulated,3protein spots were not detected and13protein spots were newly detected. In addition, Tetraploid Robinia pseudoacacia mitochondria were found102differential protein spots, of which58protein spots were up-regulated,36protein spots were down-regulated,6protein spots were not detected and2protein spots were newly detected.