首页|Towards the completion of Koch's postulates for the citrus huanglongbing bacterium,Candidatus Liberibacter asiaticus

Towards the completion of Koch's postulates for the citrus huanglongbing bacterium,Candidatus Liberibacter asiaticus

扫码查看
原文链接
  • NETL
  • NSTL
  • 万方数据
Candidatus Liberibacter asiaticus(Las)is one of the causal agents of huanglongbing(HLB),the most devastating disease of citrus worldwide.Due to the intracellular lifestyle and significant genome reduction,culturing Las in vitro has proven to be extremely challenging.In this study,we optimized growth conditions and developed a semi-selective medium based on the results of nutritional and antibiotic screening assays.Using these optimized conditions,we were able to grow Las in the LG liquid medium with ca.100-to 1000-fold increase,which peaked after 4 to 6 weeks and were estimated to contain 106 to 107 cells/ml.The cultured Las bacteria remained in a dynamic state of growth for over 20 months and displayed limited growth in subcultures.The survival and growth of Las was confirmed by fluorescence in situ hybridization with Las-specific probes and expression of its metabolic genes.Growth of Las in the optimized medium relied on the presence of a helper bacterium,Stenotrophomonas maltophilia FLMAT-1 that is multi-drug resistant and dominant in the Las co-culture system.To recapitulate the disease,the co-cultured Las was inoculated back to citrus seedlings via psyllid feeding.Although the Las-positive rate of the fed psyllids and inoculated plants were relatively low,this is the first demonstration of partial fulfillment of Koch's postulates with significant growth of Las in vitro and a successful inoculation of cultured Las back to psyllids and citrus plants that resulted in HLB symptoms.These results provide new insights into Las growth in vitro and a system for improvement towards axenic culture and anti-Las compound screening.

Desen Zheng、Cheryl M.Armstrong、Wei Yao、Bo Wu、Weiqi Luo、Charles Powell、Wayne Hunter、Feng Luo、Dean Gabriel、Yongping Duan

展开 >

USDA-ARS-USHRL,Fort Pierce,FL 34945,USA

Department of Plant Pathology,University of Florida,Gainesville,FL 32611,USA

USDA-ARS-ERRC,Wyndmoor,PA 19038,USA

IRREC,University of Florida/IFAS,For Pierce,FL 34945,USA

School of Computing,Clemson University,100 McAdams Hall,Clemson,SC 29634,USA

Center for Integrated Pest Management,North Carolina State University,Raleigh,NC 27695,USA

展开 >

NIFANIFAUSDA-ARS base funds

2016-70016-248442016-10974

2024

10.1093/hr/uhae011

园艺研究(英文)

园艺研究(英文)

CSTPCD
ISSN：
年,卷(期)：2024.11(3)
  • 48