Effect Of Endophyte Gao Y1-1 Infection On Endogenous Hormones And Organic Acids Of Rice Seedlings Under Cd And/or Al Stress

Heavy metal pollution not only damages the environment,but also has a significant effect on crop growth and production.The endophytic fungi Gao Y1-1 isolated from Suaeda salsa was used to infect rice seedlings(Liaoxing No.1).Experimental groups were divided into non-infection group(E-)and infection group(E+).Different concentrations of Cd(0,50,100,100 ?M),Al(0,40,80,120 ?M),Cd+Al(0+0,50+40,50+60,50+80 ?M)supplemented with or without 5% fermentation respectively were added to the nutrient solution.Data were collected on endogenous hormones and organic acids content in rice seedlings under the three stresses.Experiments were carried out to study the role of endopytic fungi Gao Y1-1 in enhancing rice resistance to Cd and/or Al stress.The study results showed:1.Cadmium(Cd)stress reduced the content of growth hormone in leaves and roots of rice seedlings,for example indole-3-acetic(IAA),Zeatin(Z);On the contrary,the content of abscisic acid(ABA)and salicylic acid(SA)increased;Cd stress was alleviated after adding endophyte.When the 150 ?M Cd,ABA content of E+ decreased obviously and significantly lower than that of E-group.But IAA,Z,GA3 and SA in E+ were higher than that of group E-.At the same time IAA/ABA,GA3/ABA of E+ was higher than in E-.2.The content of tartarate,succinate in leaves and malate,succinate tartarate,citate in roots showed a downward trend under Cd stress.Infection of GaoY1-1 could enhance rice resistance to Cd stress.For example,the content of malate,acetate,succinate,citate and frumarate of E+ in leaves and lactate,citate,tartarate and frumarate of E-in roots were promoted.3.IAA content presented increasing trend when low Al concentration and decreasing trend when high Al concentration.ABA content showed increasing as stress strengthening,but Z content conversely.Infection of GaoY1-1 could promote IAA and Z content in both leaves and roots,and the same effecting appeared on GA3 in leaves.IAA/ABA,Z/ABA and GA3/ABA of E+ in leaves were greater than E-.4.Lactic acid and acetic acid content in leaves of rice seedlings decreased,while the content of citric acid and tartaric acid increased under Al stress.Frumarate and citate content in roots increased.The content of lactic acid and succinic acid in leaves and frumarate and malate in roots of E+ were higher than that of E-.5.Z content presented decreasing under Cd+Al combined sress.ABA increased with stress levels rising.Z content increased significantly of E+ in both leaves and roots under Cd+Al combined stress.At the same time,the content of GA3 and SA induced by endophytes increased significantly in roots.IAA/ABA and GA3/IAA in leaves of E+ were higher than that of E-.6.The content of succinate,citate and tartarate in leaves showed decreasing trend under stress,the same effection appeared on oxalate,frumarate and citate during 40 ?M Al+50 ?M Cd ? 60 ?M Al+50 ?M Cd stress in roots.Infection of GaoY1-1 could promote organic acid content except for oxalate in leaves and roots and tartarate content in leaves.This illustrated that endophytic fungi could enhance resistance by promoting organic acid content.