|HUANG, J - South China Agricultural University|
|DAI, Z - South China Agricultural University|
|ZHENG, Z - South China Agricultural University|
|SILVIA, P.A. - Fundecitrus - Brazil|
|KUMAGAI, L - California Department Of Food And Agriculture|
|DENG, X - South China Agricultural University|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/3/2020
Publication Date: 12/30/2020
Citation: Huang, J., Dai, Z., Zheng, Z., Silvia, P., Kumagai, L., Chen, J., Deng, X. 2020. Metagenomic analyses of ACP and citrus samples infected with “Candidatus Liberibacter asiaticus” in California. American Phytopathological Society Meeting. 125:S2.53. https://apsjournals.apsnet.org/doi/epdf/10.1094/PHYTO-110-12-S2.1.
Technical Abstract: Huanglongbing (HLB) is a highly destructive disease in citrus production. The disease is associated with an unculturable proteobacterium “Candidatus Liberibacter asiaticus” (CLas), transmitted by Asian citrus psyllid (ACP, Diaphorina citri). HLB was first discovered in Southern California in 2012. Since then, the disease has been found in multiple locations. Understanding the microbiome associated with HLB has important impact for disease management. In this study, citrus and ACP CLas samples recently collected from County of San Bernardino were analyzed. A metagenomics pipeline was developed that included DNA extraction, a next-generation-sequencing (NGS) Illumina NextSeq format, and bacterial sequence grouping using a metagenomic tool (Kaiju) along with appropriate validation. In addition to CLas, sequence groups of Bradyrhizobium, Burkholderia, Mesorhizobium, Paraburkholderia, and Pseudomonas were found in both the citrus and ACP samples. Some groups had relatively high abundance. Draft genome sequences of the ACP and citrus CLas strains were obtained. Based on terL locus, the two CLas strains were in the Asiatic group with Type 1 prophages, i.e. PGT-1 group. In the sequence groups of Bradyrhizobium and Mesorhizobium, sequences highly similar to the 16S rRNA gene of CLas were detected. These sequences could potentially impact the accuracy of CLas detection using 16S rRNA gene-based PCR. Characterization of Burkholderia, Paraburkholderia and Pseudomonas groups are currently underway.