Phytopathology®


Publications
80

A Type 3 Prophage of ‘Candidatus Liberibacter asiaticus’ Carrying a Restriction-Modification System

Citation
Zheng et al. (2018). Phytopathology® 108 (4)
Names
Ca. Liberibacter asiaticus
Abstract
Prophages, the lysogenic form of bacterial phages, are important genetic entities of ‘Candidatus Liberibacter asiaticus’ (CLas), a nonculturable α-proteobacterium associated with citrus Huanglongbing. Two CLas prophages have been described, SC1 (NC_019549.1, Type 1) and SC2 (NC_019550.1, Type 2), which involve the lytic cycle and the lysogenic cycle, respectively. To explore the prophage repertoire, 523 CLas DNA samples extracted from leaf petioles of CLas-infected citrus were collected from so

Challenges for Managing Candidatus Liberibacter spp. (Huanglongbing Disease Pathogen): Current Control Measures and Future Directions

Citation
Blaustein et al. (2018). Phytopathology® 108 (4)
Names
Liberibacter
Abstract
Huanglongbing (HLB; “citrus greening” disease) has caused significant damages to the global citrus industry as it has become well established in leading citrus-producing regions and continues to spread worldwide. Insecticidal control has been a critical component of HLB disease management, as there is a direct relationship between vector control and Candidatus Liberibacter spp. (i.e., the HLB pathogen) titer in HLB-infected citrus trees. In recent years, there have been substantial efforts to d

Characterization of the Serralysin-Like Gene of ‘Candidatus Liberibacter solanacearum’ Associated with Potato Zebra Chip Disease

Citation
Ravindran et al. (2018). Phytopathology® 108 (3)
Names
“Liberibacter solanacearum”
Abstract
The nonculturable bacterium ‘Candidatus Liberibacter solanacearum’ is the causative agent of zebra chip disease in potato. Computational analysis of the ‘Ca. L. solanacearum’ genome revealed a serralysin-like gene based on conserved domains characteristic of genes encoding metalloprotease enzymes similar to serralysin. Serralysin and other serralysin family metalloprotease are typically characterized as virulence factors and are secreted by the type I secretion system (T1SS). The ‘Ca. L. solana

Development of a Tandem Repeat-Based Polymerase Chain Displacement Reaction Method for Highly Sensitive Detection of ‘Candidatus Liberibacter asiaticus’

Citation
Lou et al. (2018). Phytopathology® 108 (2)
Names
Ca. Liberibacter asiaticus
Abstract
Huanglongbing (HLB) is one of the most destructive diseases in citrus production worldwide. Early detection of HLB pathogens can facilitate timely removal of infected citrus trees in the field. However, low titer and uneven distribution of HLB pathogens in host plants make reliable detection challenging. Therefore, the development of effective detection methods with high sensitivity is imperative. This study reports the development of a novel method, tandem repeat-based polymerase chain displac

Two ‘Candidatus Liberibacter asiaticus’ Strains Recently Found in California Harbor Different Prophages

Citation
Zheng et al. (2017). Phytopathology® 107 (6)
Names
Ca. Liberibacter asiaticus
Abstract
‘Candidatus Liberibacter asiaticus’ (CLas), an α-proteobacterium, is associated with citrus Huanglongbing (HLB; yellow shoot disease). In California, two cases of CLas have been detected in Los Angeles County, one in Hacienda Heights in 2012 and the other in San Gabriel in 2015. Although all infected trees were destroyed in compliance with a state mandate, citrus industry stakeholder concerns about HLB in California are high. Little is known about the biology of CLas, particularly the Californi

Physiologic, Anatomic, and Gene Expression Changes in Citrus sunki, Poncirus trifoliata, and Their Hybrids After ‘Candidatus Liberibacter asiaticus’ Infection

Citation
Boava et al. (2017). Phytopathology® 107 (5)
Names
Ca. Liberibacter asiaticus
Abstract
Huanglongbing (HLB) is a destructive disease of citrus caused by phloem-limited bacteria, namely ‘Candidatus Liberibacter asiaticus’ (Las), ‘Candidatus Liberibacter africanus’, and ‘Candidatus Liberibacter americanus’. Although there are no known HLB-resistant citrus species, studies have reported Poncirus trifoliata as being more tolerant. Assuming that callose deposition in the phloem of infected plants can inhibit translocation of photosynthetic products and cause starch accumulation, we com

Latency and Persistence of ‘Candidatus Liberibacter asiaticus’ in Its Psyllid Vector, Diaphorina citri (Hemiptera: Liviidae)

Citation
Canale et al. (2017). Phytopathology® 107 (3)
Names
Ca. Liberibacter asiaticus
Abstract
Although ‘Candidatus Liberibacter asiaticus’ (Las) is a major pathogen associated with citrus huanglongbing (HLB), some characteristics of transmission by the psyllid vector Diaphorina citri are not fully understood. We examined the latent period and persistence of transmission of Las by D. citri in a series of experiments at 25°C, in which third-instar psyllid nymphs and 1-week-old adults were confined on infected citrus for an acquisition access period (AAP), and submitted to sequential inocu

Colonization and Intrusive Invasion of Potato Psyllid by ‘Candidatus Liberibacter solanacearum’

Citation
Cicero et al. (2017). Phytopathology® 107 (1)
Names
“Liberibacter solanacearum”
Abstract
Previous studies have shown that the fastidious bacterial plant pathogen ‘Candidatus Liberibacter solanacearum’ (CLso) is transmitted circulatively and propagatively by the potato psyllid (PoP) Bactericera cockerelli. In this study, the temporal and spatial interrelationships between CLso PoP were investigated by scanning electron microscopy of the digestive system of PoP immature and adult instars and salivary glands of adults post CLso ingestion. CLso biofilms were not detectable on the outer

Distribution of ‘Candidatus Liberibacter asiaticus’ Above and Below Ground in Texas Citrus

Citation
Louzada et al. (2016). Phytopathology® 106 (7)
Names
Ca. Liberibacter asiaticus
Abstract
Detection of ‘Candidatus Liberibacter asiaticus’ represents one of the most difficult, yet critical, steps of controlling Huanglongbing disease. Efficient detection relies on understanding the underlying distribution of bacteria within trees. To that end, we studied the distribution of ‘Ca. L. asiaticus’ in leaves of ‘Rio Red’ grapefruit trees and in roots of ‘Valencia’ sweet orange trees grafted onto sour orange rootstock. We performed two sets of leaf collection on grapefruit trees; the first

‘Candidatus Liberibacter solanacearum’ Titers in and Infection Effects on Potato Tuber Chemistry of Promising Germplasm Exhibiting Tolerance to Zebra Chip Disease

Citation
Wallis et al. (2015). Phytopathology® 105 (12)
Names
“Liberibacter solanacearum”
Abstract
Long-term sustainable management of zebra chip (ZC) disease of potato requires development of tolerant or resistant germplasm. To this end, 283 potato varieties and breeding clones were infected with the ZC putative causal agent ‘Candidatus Liberibacter solanacearum’ (Lso) by potato psyllid vector inoculations in 2010, 2011, 2012, and 2013. Potato germplasm was then examined for development of fresh and fried ZC symptoms. Over multiple years 29 breeding clones exhibited little to no symptoms in