title: Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics.
abstract: Huanglongbing (HLB) is a serious citrus disease that threatens the citrus industry. In previous studies, sulfonamide antibiotics and heat treatment suppressed 'Candidatus Liberibacter asiaticus' (Las), but did not completely eliminate the Las. Furthermore, there are few reports studying the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. In this study, combinations of heat (45°C or 40°C) and sulfonamide treatment (sulfathiazole sodium-STZ, or sulfadimethoxine sodium-SDX) were applied to HLB-affected citrus. The bacterial microbiome of HLB-affected citrus following thermotherapy and/or chemotherapy was characterized by PhyloChipTMG3-based metagenomics. Our results showed that the combination of thermotherapy at 45°C and chemotherapy with STZ and SDX was more effective against HLB than thermotherapy alone, chemotherapy alone, or a combination of thermotherapy at 40°C and chemotherapy. The PhyloChipTMG3-based results indicated that 311 empirical Operational Taxonomic Units (eOTUs) were detected in 26 phyla. Cyanobacteria (18.01%) were dominant after thermo-chemotherapy. Thermotherapy at 45°C decreased eOTUs (64.43%) in leaf samples, compared with thermotherapy at 40°C (73.96%) or without thermotherapy (90.68%) and it also reduced bacterial family biodiversity. The eOTU in phylum Proteobacteria was reduced significantly and eOTU_28, representing "Candidatus Liberibacter," was not detected following thermotherapy at 45°C. Following antibiotic treatment with SDX and STZ, there was enhanced abundance of specific eOTUs belonging to the families Streptomycetaceae, Desulfobacteraceae, Chitinophagaceae, and Xanthomonadaceae, which may be implicated in increased resistance to plant pathogens. Our study further develops an integrated strategy for combating HLB, and also provides new insight into the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics.
authors.affiliation: State Key Lab for Conservation and Utilization of Subtropical Agro-biological Resources, Guangxi University, Nanning, 530005, China.|Indian River Research and Education Center, IFAS, University of Florida, Fort Pierce, FL, 34945, United States of America.|College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
authors.forename: Chuanyu
authors.identifier: 0000-0003-1194-208X
authors.initials: C
authors.lastname: Yang
authors.affiliation: Indian River Research and Education Center, IFAS, University of Florida, Fort Pierce, FL, 34945, United States of America.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Powell
authors.affiliation: Horticultural Research Lab, USDA-ARS, Fort Pierce, FL, 34945, United States of America.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Horticultural Research Lab, USDA-ARS, Fort Pierce, FL, 34945, United States of America.
authors.forename: Robert
authors.initials: R
authors.lastname: Shatters
authors.affiliation: College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Fang
authors.affiliation: State Key Lab for Conservation and Utilization of Subtropical Agro-biological Resources, Guangxi University, Nanning, 530005, China.|Indian River Research and Education Center, IFAS, University of Florida, Fort Pierce, FL, 34945, United States of America.|College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
authors.forename: Muqing
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D044822:Biodiversity; D002957:Citrus / Q000187:drug effects* / Q000382:microbiology*; D006979:Hyperthermia, Induced; D064307:Microbiota / Q000187:drug effects*; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D013449:Sulfonamides / Q000494:pharmacology*; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D013449:Sulfonamides