Influence Of Southern Rice Black-streaked Dwarf Virus Infection And Temperature Stress On Metabolomics Of Vector White-backed Planthopper

Southern rice black-streaked dwarf virus(SRBSDV)can be only transmitted efficiently by the migratory insect white-backed planthopper(Sogatella furcifera,WBPH)in a persistent ciruculative propagative manner.Studies have shown that WBPH can not withstand the temperature above 35? and below the temperature of 4?,so the occurrence of the disease is closely related to temperature.Previous studies showed that tolerance of the WBPH to the high temperature was significantly increased,and tolerance to low temperature was significantly reduced with SRBSDV infection.In order to gain better understanding of virus-vector interaction during temperature stresses,GC-TOF-MS was used to determine the contents of all the metabolites of SRBSDV-free and SRBSDV-infected WBPH after 4 hours treatment by high temperature(36?),suitable temperature(25?)and low temperature(5?)respectively in this study.Differentially expressed metabolites and metabolic pathways in response to virus infection,temperature stress,and combined stress were identified.The results obtained in this study are as follows: 1.Using gas chromatography time-of-flight mass spectrometry(GC-TOF-MS)technology,metabolic of WBPH instar nymphs were determined.After processing,605 distinguishable peaks were selected from 632 detected peaks,and according to the Fiehn database,255(42.15%)substances were identified,including amino acids,sugars and polyols,TC A cycle intermediates,fatty acids,vitamins,alkaloids and so on.2.The infection of SRBSDV resulted in abnormal metabolism of nucleic acid in WBPH,and the nucleotide metabolism of the host nucleotides is enhanced,which had an adverse effect on virus replication.3.The SRBSDV infection accele rated the glycolysis process of the WBPH,and the fatty acid was significantly up-regulated,providing the necessary energy for the parasitic immune defense process.4.Low temperature stress mainly affects the metabolism of TCA cycle,amino acids,sugars and polyols in whitebacked planthopper.The low temperature resistance of WBPH was explained from the perspective of metabolomics.5.High temperature stress significantly induced the accumulation of ornithine in the body,and then started the heat shock protein-based stress response.6.The small molecule metabolites(?-keto acids)of amino acids,it is not conducive to the survival of WBPH at low temperatures.Sugars,polyols and antioxidant function are changed by virus infection and low temperature complex stress.7.Viral infection and high temperature complex stress caused a variety of amino acids,sugar and polyhydric alcohol changes,also induced the accumulation of ornithine in the body but not significant,and then start the heat shock protein-based stress response.Resulting in changes in fatty acid composition,accumulation of unsaturated fatty acids,but saturated fatty acids down-regulated.The change of these metabolites is more conducive to improve the resistance to high temperature of WBPH.In this study,using the GC-TOF-MS technology,some results and theories from the perspective of metabonomics will be more conducive to further explore the metabolic mechanism of SRBSDV-WBPH-temperature interaction.At the same time,it can provide new ideas for the forecasting and prevention of SRBSDV.