Detection of Candidatus Liberibacter asiaticus and five viruses in individual Asian citrus psyllid in China

Luqin Liu; Jing Chen; Junyao Jiang; Jiamei Liang; Yaqin Song; Qi Chen; Fuling Yan; Ziqin Bai; Zhen Song; Jinxiang Liu

doi:10.3389/fpls.2024.1357163

Detection of Candidatus Liberibacter asiaticus and five viruses in individual Asian citrus psyllid in China

Front Plant Sci. 2024 Feb 6:15:1357163. doi: 10.3389/fpls.2024.1357163. eCollection 2024.

Authors

Luqin Liu¹, Jing Chen¹, Junyao Jiang¹, Jiamei Liang¹, Yaqin Song², Qi Chen¹, Fuling Yan¹, Ziqin Bai³, Zhen Song¹, Jinxiang Liu¹

Affiliations

¹ Citrus Research Institute, Southwest University/National Citrus Engineering Research Center, Chongqing, China.
² Guangxi Academy of Specialty Crops, Guangxi Citrus Breeding and Cultivation Research Center of Engineering Technology, Guangxi, China.
³ Fruit Research Institute, Guizhou Provincial Academy of Agricultural Sciences, Guizhou, China.

Abstract

Introduction: Asian citrus psyllid (ACP, Diaphorina citri) is an important transmission vector of "Candidatus Liberibacter asiaticus" (CLas), the causal agent of Huanglongbing (HLB), the most destructive citrus disease in the world. As there are currently no HLB-resistant rootstocks or varieties, the control of ACP is an important way to prevent HLB. Some viruses of insect vectors can be used as genetically engineered materials to control insect vectors.

Methods: To gain knowledge on viruses in ACP in China, the prevalence of five RNA and DNA viruses was successfully determined by optimizing reverse transcription polymerase chain reaction (RT-PCR) in individual adult ACPs. The five ACP-associated viruses were identified as follows: diaphorina citri bunyavirus 2, which was newly identified by high-throughput sequencing in our lab, diaphorina citri reovirus (DcRV), diaphorina citri picorna-like virus (DcPLV), diaphorina citri bunyavirus (DcBV), and diaphorina citri densovirus-like virus (DcDV).

Results: DcPLV was the most prevalent and widespread ACP-associated virus, followed by DcBV, and it was detected in more than 50% of all samples tested. DcPLV was also demonstrated to propagate vertically and found more in salivary glands among different tissues. Approximately 60% of all adult insect samples were co-infected with more than one insect pathogen, including the five ACP-associated viruses and CLas.

Discussion: This is the first time these viruses, including the newly identified ACP-associated virus, have been detected in individual adult ACPs from natural populations in China's five major citrus-producing provinces. These results provide valuable information about the prevalence of ACP-associated viruses in China, some of which have the potential to be used as biocontrol agents. In addition, analysis of the change in prevalence of pathogens in a single insect vector is the basis for understanding the interactions between CLas, ACP, and insect viruses.

Keywords: Asian citrus psyllid; Candidatus Liberibacter asiaticus; Huanglongbing; co-infection; insect viruses.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was supported by the National Key R&D Program of China (Grant No. 2021YFD1400800).