| In this study,Hangbai chrysanthemum was test material.Chrysanthemum cuttings were sprayed with different concentrations(0,0.01,0.05,0.1,0.5,1 mmol/L)methyl jasmonic.Thereafter,the impacts of the above six treatments were determined,including the protective enzymes activities,defense enzyme activities,osmotic substances,secondary metabolites,nutrients,Protease inhibitor and key genes of the key enzymes of the jasmonic signaling pathway as well as explored the relationship between aphid resistance and the jasmonic signaling pathway in chrysanthemum.The results are as follows:1?Compared with the control,the number of aphids decreased in 5 chrysanthemum plants that treated with different concentrations of MeJA.The largest number of aphids was control,the lowest number of aphids was 0.5 mmol/ L MeJA,1 mmol/L MeJA followed.When the concentration of MeJA is low(0.01-0.1mmol/L),the number of aphids gradually decreases with the increase of the concentration.2?The plant height,internode length,leaf area,dry root weight and fresh root weight of chrysanthemum that treated with methyl jasmonate were higher than those of control.3?After inoculation with aphids,the SOD and POD activities of the control group and the MeJA treatment group showed a trend of increasing first and then decreasing,and the treatment group was higher than the control group.The SOD activity of the control group reached the maximum on the 6th day,and the POD activity reached the maximum on the 8th day.The SOD activity of the MeJA treatment group reached the maximum on days 4-6,and the POD activity reached the maximum on days 8-10.The activity of SOD and POD in chrysanthemum leaves treated with 0.5mmol/L MeJA is higher than that of other concentrations.4?After inoculation with aphids,the soluble protein content of the control group and the MeJA treatment group showed a trend of increasing first and then decreasing,and the content of the treatment group was always higher than that of the control group.The soluble protein content of the control group reached the maximum on the 8th day,and the soluble protein content of the MeJA treatment group reached the maximum on the 6th day.The soluble protein content of chrysanthemum leaves treated with 0.5mmol/L MeJA was higher than that of chrysanthemum leaves treated with other concentrations,followed by the treatment of 1mmol/L MeJA.After inoculation with aphids,the proline content of the control group and the MeJA treatment group both increased rapidly on the second day and then gradually decreased.The initial level was basically restored on the 8th day,and the content of the treatment group was significantly higher than that of the control group.The proline content of chrysanthemum leaves treated with 0.5mmol/L MeJA was higher than that of chrysanthemum leaves treated with other concentrations,followed by the treatment of 1mmol/L MeJA.On the second day after aphid stress,the content of malondialdehyde in chrysanthemum leaves of the control group and the MeJA treatment group increased to varying degrees,but the increase in the MeJA treatment group was smaller than that of the control.High concentration MeJA treatment increased less than low concentration MeJA treatment.The malondialdehyde content of the treatment group and the control group began to decrease on the 4th day,and the decrease degree of the MeJA treatment group was higher than that of the control group.5?After inoculation with aphids,the PAL and PPO activities of the control group and the MeJA treatment group showed a trend of increasing first and then decreasing,and the treatment group was higher than the control group.The PALactivity of the control group reached the maximum on the 4th day,and the PPO activity reached the maximum on the 6th day.The PAL activity of the MeJA treatment group reached the maximum on days 4-8,and the PPO activity reached the maximum on days 4-10.The activity of PAL and PPO in chrysanthemum leaves treated with 0.5mmol/L MeJA is higher than that of other concentrations,followed by the treatment of 1mmol/L MeJA.6?After inoculation with aphids,the total phenolic content of the control group and the MeJA treatment group showed a trend of increasing first and then decreasing,and the content of the treatment group was always higher than that of the control group.The total phenolic content of the control group reached the maximum on the 8th day,and the total phenolic content of the MeJA treatment group reached the maximum on days 4-6.After inoculation with aphids,the total flavonoid content of the control group and the MeJA treatment group showed a trend of first increasing,then decreasing and then increasing,and the content of the treatment group was always higher than that of the control group.The total flavonoid content of chrysanthemum leaves treated with 0.5mmol/L MeJA was higher than that of chrysanthemum leaves treated with other concentrations,followed by the treatment of 1mmol/L MeJA.After inoculation with aphids,the lignin content of the MeJA treatment group showed a trend of increasing first and then decreasing,while the trend of the control group was not obvious,but the content of the treatment group was always higher than that of the control group.The lignin content of chrysanthemum leaves treated with 0.5mmol/L MeJA was higher than that of chrysanthemum leaves treated with other concentrations,followed by the treatment of 1mmol/L MeJA.7?After inoculation with aphids,After being subjected to aphid stress,the soluble sugar content of the control group and the MeJA treatment group decreased to varying degrees,but the decrease range of the MeJA treatment group was greater than that of the control group.Chrysanthemum leaves treated with 0.5mmol / L MeJA had the largest decrease in soluble sugar content,followed by 1mmol / L MeJA.8?After inoculation with aphids,the PI activities of the control group and the MeJA treatment group showed a trend of increasing first and then decreasing,and the treatment group was higher than the control group.The TI activity of the control group reached the maximum on the 4th day,and the CI activity reached the maximum on the 6th day.The TI activity of the MeJA treatment group reached the maximum on days 4-6,and the CI activity reached the maximum on the 6th day.The activity of PI in chrysanthemum leaves treated with 0.5mmol/L MeJA is higher than that of other concentrations.9?On the second day after aphid stress,the relative expressions of CmAOS,CmJAZ and CmCOI1 genes in the control and the MeJA-treated group all increased,and the relative expressions of CmAOS and CmCOI1 genes in the MeJA-treated group were significantly higher than those in the control,while the relative expressions of CmJAZ genes in the control were significantly higher than those in the MeJA-treated group.10?After inoculation with aphids,the activity of LOX and the content of endogenous jasmonic acid in chrysanthemum leaves of the control and the MeJA treatment group showed a continuous rising trend,and the activity of LOX and the content of endogenous jasmonic acid in the MeJA treatment group were higher than that in the control. |
PDF Full Text Request