Analysis Of Different Metabolites In The Leaves Of Wogan Huanglongbing Disease

Citrus Huanglongbing is the most destructive disease in citrus production.So far,no suitable pesticide has been found to kill pathogens,and the breeding of disease-resistant varieties is not ideal.The characteristics of pathogen itself make it more and more difficult to screen and control the conventional agents.At present,there are few reports on the study of Citrus Huanglongbing based on metabonomics.In this study,the metabolites of diseased and healthy leaves of citrus were determined by GC-MS and LC-MS,and the differential metabolites related to pathogenicity were found,so as to screen the biomarkers suitable for the detection of Citrus Huanglongbing.The results are as follows:1.In this study,the occurrence of Citrus Huanglongbing was investigated in Nanning,Liuzhou,Wuming and the orchards of Guangxi University from 2019 to 2020.In three investigation sites,700 suspected samples of Huanglongbing were collected from 8 varieties of citrus plants,including Wakan,seedless Wakan,sugar orange,tangerine,Wenzhou orange,sweet orange,Jinqiu and Nanfeng orange.The results showed that 62 leaves of citrus plants were positive for Huanglongbing by fluorescence quantitative PCR and molecular identification.2.Based on LC-MS,1229 metabolites were annotated in LC-MS and 6 potential biomarkers were screened: neoliquiritigenin 2 ’-apigenin,1-methoxy-3-(4-hydroxyphenyl)-2e-propeny4’-glucoside,m-phenylacetone 6 ’-[xylose-(1-> 6)-glucoside],quinic acid,kaempferol 3-o-glucoside-(1-> 2)-rhamnoside,sucrose.3.Based on GC-MS,175 metabolites were identified in GC-MS.Based on GC-MS,seven potential biomarkers of Huanglongbing were screened out: isothreonic acid,4-methyl-2-pentene-2,4-diol,1,1-di-c-octyl-d-gluconol,3-hydroxyisopentanoic acid,1,1-di-c-octyl-d-gluconol,trans hex-2-enoic acid and inositol.Through screening the key metabolites related to the disease,it will provide scientific basis and new reference for the field diagnosis of Citrus Huanglongbing.