Endophytic EF0801 From S.salsa Infection Alleviate Damage Of Rice Seedlings Under Pb Stress

With the growth of world’s population and the expansion of the industrial scale, more and more heavy metals with life and industrial waste water flow into farmland. Heavy metals can reduce crop yields and do harm to people’s health through the food chain. As a populous country, there is little arable land in China, thus it is very important to ensure the food security. Rice is one of the major crops in China, therefore enhancing the stress resistance of heavy metals has important significance.This experiment adopts endophytes EF0801 that can promote plant growth screening from the S.salsa growth in liaoning panjin sred beach and uses the important food crop plant rice as experiment materials. The rice seedlings are stressed with 0, 50, 100, 150 and 200 μM Pb(NO3)2 and half rice seedlings are infected with 5% EF0801 microbial at the same time.Measure the rice photosynthetic parameters(photosynthetic parameters(net photosynthetic rate(Pn) and stomatal conductance(Gs), chlorophyll fluorescence parameters(the potential activity of PSII photoreaction center(Fv/Fo) and the original light energy conversion efficiency(Fv/Fm) and chlorophyll content(Chl, Chlb)), antioxidant system parameters(glutathione reductase(GR), ascorbic acid peroxidase(APX), total ascorbic acid(TASC) and reduced ascorbic acid(ASC), total glutathione(TGSH) and reduced glutathione(GSH)), proline(Pro)content, active oxygen(hydrogen peroxide(H2O2) and superoxide anion(O2-)) content, rice seedlings mineral elements(K, P, Mg, Ca, Mn, Fe) content and the content of Pb and analysis the changed trend of them. Research shows that:1.EF0801 can promote the photosynthesis of rice seedlings: Chlorophyll content and Pn of E+ group are higher than E- group, Gs of E+ group is slightly higher than E- group; Fv/Fo and Fv/Fm of E+ group are higher than E- group and have no obvious change.2.EF0801 can enhance antioxidant system capacity of rice and reduce accumulation of ROS:E+ group antioxidants content of rice seedlings is higher than E- group to a certain extent,antioxidant enzymes are slightly higher than E- group; ROS content is lower than E- group.3.EF0801 can enhance the Pro content of rice: E+group has higher Pro content than E- group.4.EF0801 can enhance rice absorption mineral elements of rice: E+group have stronger absorption K, Mg, Ca, Mn, Fe than E-group at some extent, but no significant effect of Pb content of rice.