Ravindran Aravind, Levy Julien, Pierson Elizabeth, Gross Dennis C
Department of Plant Pathology and Microbiology.
Department of Horticultural Sciences.
Plant Dis. 2011 Dec;95(12):1542-1546. doi: 10.1094/PDIS-05-11-0386.
Zebra chip disease poses a major economic threat to potato production. The causative agent is a phloem-limited bacterium identified as 'Candidatus Liberibacter solanacearum' that is transmitted by the potato/ tomato psyllid. Currently, there are no effective controls and existing control strategies depend largely on the early detection of the pathogen via polymerase chain reaction (PCR) assays. Most primer sets used for PCR detection target a region of the bacterial 16S rDNA gene, and detection of the pathogen in symptomatic potato tissue with existing primers has been variable depending on the specific primer sets used. This study describes the development of two new primer sets that target a conserved intergenic region between the 16S and 23S rDNA genes and a conserved bacterial housekeeping gene, adenylate kinase (adk). Results demonstrate that the new primer sets are more reliable in detecting 'Ca. L. solanacearum' in field and glasshouse samples than the currently used LsoF/OI2 primers. The newly developed primers differentiated between 'Ca. L. solanacearum' and a closely related 'Ca. Liberibacter' spp. and were more sensitive than the LsoF/OI2 primers. The low detection limit for the new primers was four times lower (0.65 ng) than the limit (2.5 ng) for the LsoF/OI2 primers.
马铃薯斑纹片病对马铃薯生产构成重大经济威胁。其病原体是一种韧皮部受限细菌，被鉴定为“番茄伪菌 Liberibacter solanacearum”，由马铃薯/番茄木虱传播。目前，尚无有效的防治方法，现有的防治策略主要依赖于通过聚合酶链反应（PCR）检测早期发现病原体。大多数用于PCR检测的引物组靶向细菌16S rDNA基因的一个区域，使用现有引物在有症状的马铃薯组织中检测病原体的结果因所用的特定引物组而异。本研究描述了两种新引物组的开发，它们靶向16S和23S rDNA基因之间的保守基因间隔区以及一个保守的细菌管家基因腺苷酸激酶（adk）。结果表明，新引物组在检测田间和温室样品中的“Ca. L. solanacearum”方面比目前使用的LsoF/OI2引物更可靠。新开发的引物能够区分“Ca. L. solanacearum”和密切相关的“Ca. Liberibacter”属。并且比LsoF/OI2引物更敏感。新引物的低检测限（0.65 ng）比LsoF/OI2引物的检测限（2.5 ng）低四倍。
