| Dendrolimus tablaeformis Tsai et Liu is an important defoliator pest that harms pine trees in China.It is a typical nocturnal phototaxis insect,but its phototaxis behavior and mechanism have not been clearly reported.In this study,the phototaxis of D.tablaeformis was used as the starting point.By comparing the adults'phototaxis and ERG responses to LEDs with different wavelengths,the phototaxis preference of D.tablaeformis to 365nm UVA was identified.Based on this,we observed the changes in the internal microstructure of compound eyes,studied the changes of antioxidant enzymes and detoxifying enzymes,and the differences in transcriptome and proteome during different time of 365nm UVA radiation.Analyzed the response of D.tablaeformis to UVA radiation at different times from the aspects of morphological and structural adaptation,physiology,biochemistry and bioinformatics,in order to provide a reference for the efficiently use of light to control D.tablaeformis,and provide data support for studying the effects of UVA radiation on D.tablaeformis.The main results are as follows:1 The phototaxis of D.tablaeformis to LED light at 365nm wavelength was clarified.The field light trapping and indoor phototaxis control experiments shown that the tendency of the D.tablaeformis to UVA 365 nm and 380 nm LED lamps is significantly higher than that of 420 nm and 470 nm LED lamps in the blue light region,and the largest number of D.tablaeformis was trapped by 365 nm LED lamps in the field.The peak period for females and males to light is 23:30-1:00.It was recommended time to trap moths during night.LED lights were convenient to use in the forest and had good energy saving effects.2 The changes of the internal microstructure of the D.tablaeformis's compound eyes under dark adaptation and 365nm UVA light adaptation were clarified.The compound eyes of the D.tablaeformis were hemispherical,the ommatidia in the middle surface of the compound eyes were covered with ommatrichia,and the ommatidium were regular hexagons.The internal structure of compound eyes of D.tablaeformis was typical superposition eyes.Clarified the position of the rhabdome in the compound eyes,which can provide support for subsequent retinal potential test in the dark,the crystallin cone were arranged closely,and the pigment particles were concentrated around the cone.Under 365nm UVA irradiation,the distance between the cones becomes larger with the increase of the irradiation time,and the pigment particles gradually become transparent.No significantly difference in compound eyes between females and males were observed in external morphology and internal structure.3 The waveform of the ERG in D.tablaeformis and its ERG response to eight different wavelengths of lights were clarified.The waveform of ERG consists of a single-phase negative potential and a closed light response;the light intensity of light of different wavelengths at the same voltage shows a tendency to increase with increasing wavelength,but the light intensity does not appear in the retinal potential response With the increase of light intensity,the trend of ERG value increases,indicating that light intensity is not a decisive factor affecting retinal potential.Except for 365 nm,there was no significant difference in the response of D.tablaeformis to the ERG of LED lamps at 380,420,470,520,590,610 and 655nm,this result might be related to the types of photoreceptor proteins in the retinal cells of D.tablaeformis,and also might be one of the reasons that the 365 nm LEDs have the best trapping effect for D.tablaeformis.4 The changes of antioxidant enzymes and detoxifying enzymes in D.tablaeformis under different UVA irradiation time were measured.The changes of the main antioxidant enzymes,detoxifying enzymes and related intermediate products were measured by a microplate reader when the 365nm wavelength LED lights were irradiated at 0,5,15,30,60and 120 minutes.According to the change of MDA content,it was confirmed that the pine caterpillar had a peroxidation reaction during UVA radiation.SOD,CAT,and POD work together to remove superoxide radicals and H2O2.There were feedback adjustments between GPX,GST and GR,which work together to maintain the stability of GSH and GSSH and remove excess oxygen free radicals.Ach E enzyme activity increased in the early stage of UVA radiation,decomposed acetylcholine,and maintained the normal transmission of nerve impulses of D.tablaeformis,and then fluctuated with the increase of irradiation time.Under UVA radiation,the internal environment of the Chinese pine caterpillar turned acidic,and the ACP activity increased,but the ALP activity did not change significantly.The changes of antioxidant and detoxifying enzymes between females and males for different times of UVA irradiation were not consistent.It was speculated that the main task of females was to spawn and breed the next generation.To resist the oxidative stress caused by UVA radiation and smoothly spawn and reproduce,females present more complex response than males.5 Construction of the transcriptome of D.tablaeformis under different time of irradiation by 365nm LED lights.A total of 277,631 unigenes were assembled,and about58.53%of unigenes were annotated in the database.126 unigenes related to rhodopsin and opsin were identified,59 unigenes related to UV radiation response,63 unigenes related to retina,28 unigenes related to circadian rhythm.At different times of UVA irradiation,there were significant differences in the number and expression of differentially expressed genes between females and males of D.tablaeformis,and the number of differentially expressed genes in females was significantly higher than that in males.Among females,differential gene enrichment related to oocyte division and energy metabolism is the most abundant.It is speculated that under the stimulation of UVA radiation,the gene replication and other functions of females are disturbed,and pathways such as mismatch repair,nucleotide excision repair,and RNA monitoring are activated,reducing mutations caused by UVA radiation,and spawning normally.Under UVA irradiation,in addition to basal metabolic processes,innate immune pathways such as lysosomes,proteasomes,hemolymph system,Toll and Imd signaling pathways in D.tablaeformis were activated to resist damage caused by UVA radiation.6 The proteomes of the D.tablaeformis under different time of light irradiation were constructed,and 3186 proteomes were identified.5 proteins related to rhodopsin and opsin,3 proteins related to UV radiation response,9 proteins related to retinal,4 proteins related to circadian rhythm,2 cryptochrome proteins,2 cyclins proteins,3 clock proteins.At different times of UVA irradiation,there were significant differences in the quantity and expression of differentially expressed proteins between females and males of D.tablaeformis.Females had significantly more differentially expressed proteins and proteins than males.KEGG enrichment results suggested that after UVA radiation,the D.tablaeformis had a stress response through light transduction,and a series of immune-related lysosomes and cytochrome P450 functions were activated to deal with the stress caused by UVA radiation.This study clarified the phototaxis preference of D.tablaeformis for 365 nm LED,and studied the internal structure adaptation of compound eyes,physiological,biochemical and bioinformatics aspects of D.tablaeformis under 365 nm UVA radiation.These results provide a technical reference for the rational use of LED lights to control D.tablaeformis and lay the foundation for further study of the response mechanism of D.tablaeformis to UVA radiation. |
PDF Full Text Request