scholarly journals Effect of Plant Age, Temperature and Vector Load on ‘Candidatus Liberibacter solanacearum’ in planta titer and Shoot Proliferation Symptoms in Carrot

2021 ◽  
Author(s):  
Atalya Keshet-Sitton ◽  
Alon Piasetzky ◽  
Nofar Shoshana ◽  
Orit Dror ◽  
Ofir Bahar
Keyword(s):  
Shoot Proliferation ◽  
Early Summer ◽  
Plant Age ◽  
Negative Bacterium ◽  
In Planta ◽  
Candidatus Liberibacter Solanacearum ◽  
Critical Effect ◽  
Associated Symptoms ◽  
Candidatus Liberibacter ◽  
Progress Rate

A decade ago, shoot proliferation symptoms (witches’ broom) in carrots were believed to be the cause of ‘Candidatus Phytoplasma’ and/or Spiroplasma infection, yet in recent years, this association appeared to have weakened and a closer association was found with the yet-unculturable, psyllid-transmitted Gram-negative bacterium, ‘Candidatus Liberibacter solanacearum’. In Israel, carrots are grown throughout the year, yet shoot proliferation symptoms tend to appear only in mature plants and mostly during late spring to early summer. We hypothesized that factors such as plant age, temperature and vector load, which vary along the year, have a critical effect on symptoms development and set to examine these factors under controlled conditions. Here we show that young carrot seedlings are as prone as older plants, to develop shoot proliferation symptoms, following ‘Ca. L. solanacearum’ inoculation. Surprisingly, we found that the local ‘Ca. L. solanacearum’ haplotype was extremely sensitive to constant temperature of 30˚C, which led to a significant reduction in bacterial growth and symptoms development, compared with 18˚C which was very conducive for symptoms development. We have also found that inoculations with 10 or 20 psyllids per plant results in faster symptoms development compared with inoculations with 2 psyllids per plant, however, the disease progress rate was insignificant among the different vector loads. These data provide important insight to the effects of plant age, temperature and vector load on ‘Ca. L. solanacearum’ and its associated symptoms and strengthen the notion that ‘Ca. L. solanacearum’ is the main responsible agent for carrot witches broom in Israel.

Differences in Zebra Chip Severity between ‘Candidatus Liberibacter Solanacearum’ Haplotypes in Texas

2018 ◽  
Vol 96 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Kyle Harrison ◽  
Cecilia Tamborindeguy ◽  
Douglas C. Scheuring ◽  
Azucena Mendoza Herrera ◽  
Adrian Silva ◽  
...  
Keyword(s):  
Zebra Chip ◽  
Candidatus Liberibacter Solanacearum ◽  
Candidatus Liberibacter

scholarly journals Identification of Autophagy-Related Genes in the Potato Psyllid, Bactericera cockerelli and Their Expression Profile in Response to ‘Candidatus Liberibacter Solanacearum’ in the Gut

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1073
Author(s):  
Xiao-Tian Tang ◽  
Cecilia Tamborindeguy
Keyword(s):  
Expression Profile ◽  
Profile Analysis ◽  
Plant Viruses ◽  
Insect Vectors ◽  
Potato Psyllid ◽  
Bactericera Cockerelli ◽  
Candidatus Liberibacter Solanacearum ◽  
Expression Profile Analysis ◽  
Candidatus Liberibacter

Autophagy, also known as type II programmed cell death, is a cellular mechanism of “self-eating”. Autophagy plays an important role against pathogen infection in numerous organisms. Recently, it has been demonstrated that autophagy can be activated and even manipulated by plant viruses to facilitate their transmission within insect vectors. However, little is known about the role of autophagy in the interactions of insect vectors with plant bacterial pathogens. ‘Candidatus Liberibacter solanacearum’ (Lso) is a phloem-limited Gram-negative bacterium that infects crops worldwide. Two Lso haplotypes, LsoA and LsoB, are transmitted by the potato psyllid, Bactericera cockerelli and cause damaging diseases in solanaceous plants (e.g., zebra chip in potatoes). Both LsoA and LsoB are transmitted by the potato psyllid in a persistent circulative manner: they colonize and replicate within psyllid tissues. Following acquisition, the gut is the first organ Lso encounters and could be a barrier for transmission. In this study, we annotated autophagy-related genes (ATGs) from the potato psyllid transcriptome and evaluated their expression in response to Lso infection at the gut interface. In total, 19 ATGs belonging to 17 different families were identified. The comprehensive expression profile analysis revealed that the majority of the ATGs were regulated in the psyllid gut following the exposure or infection to each Lso haplotype, LsoA and LsoB, suggesting a potential role of autophagy in response to Lso at the psyllid gut interface.

scholarly journals Carrot Pathogen ‘Candidatus Liberibacter solanacearum’ Haplotype C Detected in Symptomless Potato Plants in Finland

2018 ◽  
Vol 61 (1) ◽  
pp. 31-50 ◽  
Author(s):  
Minna Haapalainen ◽  
Satu Latvala ◽  
Marika Rastas ◽  
Jinhui Wang ◽  
Asko Hannukkala ◽  
...  
Keyword(s):  
Candidatus Liberibacter Solanacearum ◽  
Potato Plants ◽  
Candidatus Liberibacter

Probing the application of OmpA-derived peptides to disrupt the acquisition of ‘Candidatus Liberibacter asiaticus’ by Diaphorina citri

2021 ◽  
Author(s):  
Marcus Vinicius Merfa e Silva ◽  
Eduarda Regina Fischer ◽  
Mariana de Souza e Silva ◽  
Carolina Sardinha Francisco ◽  
Helvécio Coletta-Filho ◽  
...  
Keyword(s):  
Control Strategies ◽  
Insect Vector ◽  
Diaphorina Citri ◽  
Candidatus Liberibacter Asiaticus ◽  
In Planta ◽  
Host Interaction ◽  
Vector Population ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Bacterial Outer Membrane

Huanglongbing (HLB) is currently the most devastating disease of citrus worldwide. Both bacteria ‘Candidatus Liberibacter asiaticus’ (CLas) and ‘Ca. Liberibacter americanus’ (CLam) are associated with HLB in Brazil, but with a strong prevalence of CLas over CLam. Conventionally, HLB management focuses on controlling the insect vector population (Diaphorina citri; also known as Asian citrus psyllid – ACP) by spraying insecticides, an approach demonstrated to be mostly ineffective. Thus, development of novel more efficient HLB control strategies is required. The multifunctional bacterial outer membrane protein OmpA is involved in several molecular processes between bacteria and their hosts and has been suggested as a target for bacterial control. Curiously, OmpA is absent in CLam in comparison to CLas, suggesting a possible role on host-interaction. Therefore, in the current study, we have treated ACPs with different OmpA-derived peptides aiming to evaluate the acquisition of CLas by the insect vector. Treatment of psyllids with 5 µM of Pep1, Pep3, Pep5 and Pep6 in artificial diet significantly reduced the acquisition of CLas, while increasing the concentration of Pep5 and Pep6 to 50 µM abolished this process. In addition, in planta treatment with 50 µM of Pep6 also significantly decreased the acquisition of CLas and sweet orange plants stably absorbed and maintained this peptide for as long as three months post the final application. Together, our results demonstrate the promising use of OmpA-derived peptides as a novel biotechnological tool to control CLas.

“Candidatus Liberibacter solanacearum” infection of commercial tomatillo, Physalis ixocarpa Brot. (Solanales: Solanaceae) in Saltillo, Mexico

Plant Disease ◽  
2021 ◽  
Author(s):  
Cesar Alejandro Reyes Corral ◽  
W. Rodney Cooper ◽  
Alexander V Karasev ◽  
Carolina Delgado-Luna ◽  
SERGIO R. Sanchez-PENA
Keyword(s):  
Content Analysis ◽  
Solanum Tuberosum L ◽  
Gut Content Analysis ◽  
Bactericera Cockerelli ◽  
Gut Content ◽  
Candidatus Liberibacter Solanacearum ◽  
Solanum Lycopersicum L ◽  
Foliar Symptoms ◽  
Candidatus Liberibacter ◽  
Psyllid Yellows

The potato psyllid, Bactericera cockerelli (Šulc), (Hemiptera: Triozidae) is a pest of Solanaceous crops (Solanales) including potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.). Feeding by high populations of nymphs causes psyllid yellows while adults and nymphs are vectors of the plant pathogen, “Candidatus Liberibacter solanacearum” (Lso). Foliar symptoms that were consistent with either Lso-infection or psyllid yellows were observed in 2019 on tomatillo (Physalis ixocarpa Brot.; Solanaceae) grown within an experimental plot located near Saltillo, Mexico. This study had three primary objectives: 1) determine whether the foliar symptoms observed on tomatillo were associated with Lso infection, 2) identify the haplotypes of Lso and potato psyllids present in the symptomatic plot, and 3) use gut content analysis to infer the plant sources of Lso-infected psyllids. Results confirmed that 71% of symptomatic plants and 71% of psyllids collected from the plants were infected with Lso. The detection of Lso in plants and psyllids, and the lack of nymphal populations associated with psyllid yellows strongly suggests that the observed foliar symptoms were caused by Lso infection. All infected plants and insects harbored the more virulent Lso haplotype B, but one psyllid was also co-infected with haplotype A. The potato psyllids were predominantly of the central haplotype, but one psyllid was identified as the western haplotype. Molecular gut content analysis of psyllids confirmed the movement of psyllids between non-crop habitats and tomatillo and indicated that Lso infection of psyllids was associated with increased plant diversity in their diet.

scholarly journals Potential Distribution and the Risks of Bactericera cockerelli and Its Associated Plant Pathogen Candidatus Liberibacter Solanacearum for Global Potato Production

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 298
Author(s):  
Jing Wan ◽  
Rui Wang ◽  
Yonglin Ren ◽  
Simon McKirdy
Keyword(s):  
At Risk ◽  
South America ◽  
Plant Pathogen ◽  
Potato Production ◽  
Economic Losses ◽  
Bactericera Cockerelli ◽  
Ecological Niche Models ◽  
Potato Acreage ◽  
Candidatus Liberibacter Solanacearum ◽  
Candidatus Liberibacter

The tomato potato psyllid (TPP), Bactericera cockerelli, is a psyllid native to North America that has recently invaded New Zealand and Australia. The potential for economic losses accompanying invasions of TPP and its associated bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), has caused much concern. Here, we employed ecological niche models to predict environments suitable for TPP/CLso on a global scale and then evaluated the extent to which global potato cultivation is at risk. In addition, at a finer scale the risk to the Australian potato acreage was evaluated. A total of 86 MaxEnt models were built using various combinations of settings and climatic predictors, and the best model based on model evaluation metrics was selected. Climatically suitable habitats were identified in Eurasia, Africa, South America, and Australasia. Intersecting the predicted suitability map with land use data showed that 79.06% of the global potato cultivation acreage, 96.14% of the potato production acreage in South America and Eurasia, and all the Australian potato cropping areas are at risk. The information generated by this study increases knowledge of the ecology of TPP/CLso and can be used by government agencies to make decisions about preventing the spread of TPP and CLso across the globe.

scholarly journals The in Planta Effective Concentration of Oxytetracycline Against ‘Candidatus Liberibacter asiaticus’ for Suppression of Citrus Huanglongbing

2019 ◽  
Vol 109 (12) ◽  
pp. 2046-2054 ◽  
Author(s):  
Jinyun Li ◽  
Zhiqian Pang ◽  
Shuo Duan ◽  
Donghwan Lee ◽  
Vladimir G. Kolbasov ◽  
...  
Keyword(s):  
Field Experiments ◽  
Foliar Spray ◽  
Effective Control ◽  
Candidatus Liberibacter Asiaticus ◽  
In Planta ◽  
Fresh Tissue ◽  
Minimum Concentration ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Residue Levels

Huanglongbing (HLB) or greening currently is the most devastating citrus disease worldwide. The fastidious phloem-colonizing bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) is the causal agent of citrus HLB in Florida. Bactericides containing the active ingredient oxytetracycline (OTC) have been used in foliar spray to control citrus HLB in Florida since 2016. However, the minimum concentration of OTC required to suppress CLas in planta remains unknown. We developed a new method for evaluating the effects of OTC treatment on CLas titers in infected plants and determined the relationship between OTC residue levels and control levels achieved for CLas using mathematical modeling in greenhouse and field experiments. In both greenhouse and field, OTC spray did not reduce the titers of CLas, and it produced undetectable or mild levels of OTC residue in leaves within 7 days post-application (DPA). In greenhouse, OTC injection at 0.05 g per tree decreased CLas titers to an undetectable level (cycle threshold value ≥ 36.0) from 7 to 30 DPA and produced a residue level of OTC at 0.68 to 0.73 µg/g of fresh tissue over this period. In the field, OTC injection at 0.50 g per tree resulted in the decline of CLas titers by 1.52 log reduction from 14 to 60 DPA, with residue levels of OTC at 0.27 to 0.33 µg/g of fresh tissue. In both trials, a first-order compart model of OTC residue dynamics in leaves of trunk-injected trees was specified for estimating the retention of effective concentrations. Furthermore, nonlinear modeling revealed significant positive correlations between OTC residue levels in leaves and the control levels for CLas achieved. The results suggested that the minimum concentrations of OTC required to suppress CLas populations in planta to below the detection limit are 0.68 and 0.86 µg/g and that the minimum concentrations of OTC required for initial inhibition of CLas growth in planta are ∼0.17 and ∼0.215 µg/g in leaf tissues under greenhouse and field conditions, respectively. This finding highlights that a minimum concentration of OTC should be guaranteed to be delivered to target CLas in infected plants for effective control of citrus HLB.

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