Stress-response Of Adults Of The Ectropis Grisescens Warren To Green Light Stimulation

For most insects,light is an important environmental signal.Ectropis grisescens Warren is an important leaf-eating pest in the main tea producing areas in China.The use of special light waves to induce and control the insect pest has the advantages of no pesticide residues,little impact on the environment,and easy operation,which widely used in production practice.However,there are few studies on the physiological,biochemical and molecular mechanisms of its response to light stress,and there is little report about the stressing effect of long-wavelength visible light on the E.grisescens.In this paper,we studied the stress response mechanism of E.grisescens adult to green light stimulation,which provided a theoretical basis for further utilizing green light to control the population of E.grisescens in tea gardens.The research results are as follows:1.Interference effect of monochromatic green light with different light intensities on the mating and reproduction behavior of E.grisescens adultsUnder indoor conditions,the monochromatic green light of 10 lx,20 lx,30 lx and 40 lx were used to interfere with the mating activity of E.grisescens.When light intensity was 40 lx,the mating success rate,average number of eggs laid by mating success female and unsuccess female,hatching rate were 38.0%,225.8 per female,65.8 per female and 90.0%respectively,while those in the dark condition were 68.0%,308.8 per female,101.9 per female and 97.9%,the difference between treatment and control was significant.2.Effects of monochromatic green light on the gene expression of male and female adults of E.grisescens77 651 functional genes(unigenes)were obtained with an average size of 840 base pairs(bp),of which 36 767(47.35%)matched public databases.According to the set differential combinations,2 845 differential expressed genes were identified.Compared with the dark control,the number of differential expressed genes in males was more than that in females after treated by green light,which indicating that male were more sensitive to green light signals than female.KEGG enrichment analysis of differential expressed genes indicated that the differential expressed genes mainly involved ECM-receptor interaction,Fatty acid biosynthesis,ABC transporters,phototransduction-fly,drug metabolism-other enzyme and etc.3.Stimulation effects of monochromatic green light on the activities of four metabolic enzymes of E.grisescens adultUnder the stimulation of green light,the enzyme activities of superoxide dismutase(SOD),Peroxide enzyme(POD)and glutathione S-transferase(GST)all showed a trend of falling-rising-falling,and the enzyme activity reached the lowest level at 6th hour,which was significantly lower than that of the control group.Catalase(CAT)showed a trend of rising-falling-smooth.The CAT activity of males was lower than the control group at 3-6 h,and the CAT activity of females was not significantly different from that of the control group at 2-6 h.4.Cloning and expression analysis of opsin genesThe open reading frames and amino acid sequences of ultraviolet light sensitive opsin gene(Eg-uv),blue light sensitive opsin gene(Eg-bs)and long wavelength sensitive opsin gene(Eg-lw)were cloned by RT-PCR.The analysis of the structure showed that the amino acid sequences encoded by the three opsin genes of E.grisescens contained seven transmembrane topologies and were in line with the characteristics of the sensitive opsin family.Sequence alignment and phylogenetic analysis showed that the opsins were the closest relative to Biston betularia.The relative expression levels of three opsin genes under the condition of dark and green light were detected by real-time quantitative PCR.The results showed that the expression trends of opsin genes for female and male were basically similar under the two conditions,but there were certain differences between the male and female under the two conditions.The changes of different opsin genes are closely correlated with external light environment.Compared with the dark condition,the expression of uv in males was down-regulated under green light,and there was a significant difference in lw at the 6th hour.The uv in females was up-regulated,and the expression peak of lw disappeared at 6th hour.There was no significant difference in the expression level of bs between male and female under green light and dark conditions,but the expression level under green light was slightly higher than that under dark treatment.