Effect On Sequence And Enzyme Activity Of Gst,Population Dynamics Of Offspring Of Sitobion Avenae Under Long Term UV-B Stress

Sitobion avenae(Fabricius))is a kind of wheat aphid,distributed in major wheat-growing areas in our country.Sitobion avenae not only eat leaf,stem and drink the juice of wheat,affect the normal development and yields of wheat,seriously can results in the stagnation of growth and withered leaves of wheat,can also transmit the virus to have a significant impact on yield and quality of crop.Therefore,it is important to expiore the corresponding defense mechanism to Make the population survival and reproduction when S.avenae is under the environment of stress,S.avenae is a typical R,has short generation cycle,fast breeding,adapt to environmental change quickly,can be an ideal material to research environmental stresses.S.avenae is experimental material in the study,we used different UV-B treatments(0 mW/cm2,0.5 mW/cm2,0.7 mW/cm2)on S.avenae in successive generations,each generation of S.avenae adults were radiated for 48h(16h everyday),and finished the determination of enzyme activity of GST of S.avenae in the first generation,the sixth generation,the eleventh generation and the sixteenth generation.Design the specific primers,augment a part of aphid mutant gene of aphid irradiated by UV-B and no treated by UV-B,mutation gene sequence,sequencing,and deduces the corresponding amino acid.Besides,the age-specific life table was established to explore the effects of offspring of S.avenae when mother generation was radiated to different intensities of UV-B for one generation,six generations,eleven generations,fifteen generations(the life table of 2nd,7th,12 th,16th generations).By knowing the influence of UV-B on the enzyme activity of GST and gene sequence for many generations treatment to find out the defensive mechanism of GST defense mechanism of S.avenae and provide a new train of thought for ecological prevention and control of S.avenae.The result shows that:1.Used RT-PCR to clone the cDNA sequences of GST gene and get the login number: KX015769.According to the ORF Finder analysis of NCBI,we found that the GST gene included an open reading frame of 651 bp,encoded 216 amino acids,the initiation codon is ATG,while termination codon is TAG.2.There were two mutant sites in the first,eleventh,and sixteenth generation,while existed three mutant sites in the sixth generation under low intensity UV-B;There were two mutant sites in the sixth,eleventh,and sixteenth generation,while made three mutant sites in the first generation under high intensity UV-B.It showed that the genetic sequences of high intensity processing multipoint mutation in advance to the first generation.In addition,the mutation sites are all the same,two base mutation sites were: C-T(399),G-A(624),three base mutation sites were C-T(399),T-A(408),G-A(624),there were no site lost and inserted.3.Analyze the amino acid sequence encoding,we can see the base substitutions occurred at the third site of codon.The results from the base substitution,it is obvious that base substitution is given priority to conversion,and amino acids encoded are synonymous substitutions.4.The effect of long-term UV-B stress on the enzyme activity of GST of S.avenae is significant in different generations.The results showed that no significant difference was found in the treatments groups;Among the treatment group of each generation under low intensity UV-B,first rose,the activity of GST first rose then declined and increased a little bit at last,reaching the peak in the 6th generation and falling to the minimum value in the 11 th generation.Additionally,the activity of GST first increased and then fell with the increase of the generations under high intensity UV-B,also reached the peak in the 7th generation,and falling to the minimum value in the 1st generation.5.The mother generation of S.avenae was radiated to different intensities of UV-B(0,0.5,0.7 mW/cm2)for one,six,eleven,and fifteen generations.The results showed that: the intrinsic rate of increase(r)and finite rate of increase(?)had no significant differences among the treatment group of each generation under low intensity UV-B,whereas the parameters of r and ?first increased and then fell with generations under high intensity UV-B.When S.avenae were under the different intensity of UV-B radiation in the same generation,most of parameters in the treatments groups were significantly lower than those in the control except the parameter T in 2nd and 16 th generation,only no significant difference was found in the 7th generation between the control groups and treatment groups,While the parameter of F,R0,T,oviposition days,and adult longevity all have significant difference,but were not significantly different between other parameters in the 12 th generation.The effect of long term UV-B stress on S.avenae would be accumulated in the progeny,had different impact on S.avenae of different generation.Besides,the survival rate of filial generation of S.avenae exposed to UV-B stress was significantly influenced.