Actividad de dos hongos entomopatógenos, identificados molecularmente, sobre Bactericera cockerelli

2017 ◽  
Vol 43 (1) ◽  
pp. 27 ◽  
Author(s):  
Fabiola Villegas-Rodríguez ◽  
Ovidio Díaz-Gómez ◽  
J. Sergio Casas-Flores ◽  
Clara Teresa Monreal-Vargas ◽  
Fernando Tamayo-Mejía ◽  
...  

El psílido de la papa Bactericera cockerelli afecta a las solanáceas en México, por el daño directo que causa, además, de que es transmisor de patógenos procariotes como Candidatus Liberibacter solanacerum (psyllaurous). Este insecto es combatido principalmente con productos químicos. Sin embargo, en la actualidad, se buscan nuevas estrategias para su manejo como el uso de hongos entomopatógenos. El objetivo de este trabajo fue evaluar la susceptibilidad del psílido de la papa a dos cepas comerciales y dos nativas de Metarizhium anisopliae y Beauveria bassiana, así como confirmar la identificación de las mismas mediante técnicas moleculares. Los bioensayos se realizaron con la cepa nativa MA25 de M. anisopliae y las comerciales Metabich® (MA28) y Bassianil® (BB09) y la nativa BB42 de Be. bassiana. Se probaron cinco concentraciones sobre ninfas del tercer estadio de B. cockerelli y se obtuvieron sus CL50 y CL95. Todas las cepas resultaron patógenas para el psílido de la papa, las más tóxicas fueron BB09, BB42 y MA28. La mortalidad fluctuó entre 90 a 100% con las concentraciones más altas de cada cepa: la más virulenta fue BB09, con una CL50 de 2,99 x 104 conidias mL-1 y MA25 la menos virulenta tuvo una CL50 de 6,34 x 105 conidias ml-1. Mediante la clonación y la secuenciación de la región ITS de los rADN 18S, se corroboró que las cepas nativas identificadas por morfología microscópica y claves taxonómicas corresponden a Be. bassiana y M. anisopliae.

2016 ◽  
Vol 106 (2) ◽  
pp. 142-154 ◽  
Author(s):  
J. M. Cicero ◽  
T. W. Fisher ◽  
J. K. Brown

The potato psyllid Bactericera cockerelli is implicated as the vector of the causal agent of zebra chip of potato and vein-greening of tomato diseases. Until now, visual identification of bacteria in the genus ‘Candidatus Liberibacter’ has relied on direct imaging by light and electron microscopy without labeling, or with whole-organ fluorescence labeling only. In this study, aldehyde fixative followed by a coagulant fixative, was used to process adult psyllids for transmission electron microscopy (TEM) colloidal gold in situ hybridization experiments. Results indicated that ‘Ca. Liberibacter solanacearum’ (CLso)-specific DNA probes annealed to a bacterium that formed extensive, monocultural biofilms on gut, salivary gland, and oral region tissues, confirming that it is one morphotype of potentially others, that is rod-shaped, approximately 2.5 µm in diameter and of variable length, and has a rough, granular cytosol. In addition, CLso, prepared from shredded midguts, and negatively stained for TEM, possessed pili- and flagella-like surface appendages. Genes implicating coding capacity for both types of surface structures are encoded in the CLso genome sequence. Neither type was seen for CLso associated with biofilms within or on digestive organs, suggesting that their production is stimulated only in certain environments, putatively, in the gut during adhesion leading to multiplication, and in hemolymph to afford systemic invasion.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1073
Author(s):  
Xiao-Tian Tang ◽  
Cecilia Tamborindeguy

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.


Plant Disease ◽  
2021 ◽  
Author(s):  
Cesar Alejandro Reyes Corral ◽  
W. Rodney Cooper ◽  
Alexander V Karasev ◽  
Carolina Delgado-Luna ◽  
SERGIO R. Sanchez-PENA

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.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 298
Author(s):  
Jing Wan ◽  
Rui Wang ◽  
Yonglin Ren ◽  
Simon McKirdy

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Carlos A. Avila ◽  
Thiago G. Marconi ◽  
Zenaida Viloria ◽  
Julianna Kurpis ◽  
Sonia Y. Del Rio

Abstract The tomato-potato psyllid (TPP), Bactericera cockerelli, is a vector for the phloem-limited bacterium Candidatus Liberibacter solanacearum (Lso), the causative agent of economically important diseases including tomato vein-greening and potato zebra chip. Here, we screened 11 wild tomato relatives for TPP resistance as potential resources for tomato (Solanum lycopersicum) cultivar development. Six accessions with strong TPP resistance (survival <10%) were identified within S. habrochaites, S. pennelli, S. huaylasense, S. chmielewskii, S. corneliomulleri, and S. galapagense. Two S. pennelli and S. corneliomulleri accessions also showed resistance to Lso. We evaluated recombinant inbred lines (RILs) carrying resistance from S. habrochaites accession LA1777 in the S. lycopersicum background and identified major quantitative trait loci (QTLs) responsible for adult TPP mortality and fecundity in several RILs carrying insertions in different chromosomes, indicating the polygenic nature of these traits. Analysis of a major resistance QTL in RIL LA3952 on chromosome 8 revealed that the presence of Lso is required to increase adult TPP mortality. By contrast, the reduced TPP oviposition trait in LA3952 is independent of Lso. Therefore, resistance traits are available in wild-tomato species, although their complex inheritance and modes of action require further characterisation to optimise their utilisation for tomato improvement.


2010 ◽  
Vol 11 (1) ◽  
pp. 33 ◽  
Author(s):  
James M. Crosslin ◽  
Joseph E. Munyaneza ◽  
Judith K. Brown ◽  
Lia W. Liefting

Potato zebra chip (ZC) disease is a relative newcomer to the world of important potato diseases. First reported in Mexico in the 1990s, by 2004-2005 the disease was causing serious economic damage in parts of Texas. ZC is now widespread in the south-western and central United States, Mexico, Central America, and was recently reported in New Zealand. By 2006, there seemed to be an association between ZC and the potato psyllid (Bactericera cockerelli). The exact nature of the relationship, however, has only recently been identified by the discovery of a new Candidatus Liberibacter bacterium that is transmitted to potatoes, tomatoes, and other solanaceous hosts by the potato psyllid. This review examines the history of this disease, the association of ZC with the potato psyllid, the host range, and recent research into the bacterial pathogen. Accepted for publication 15 December 2009. Published 17 March 2010.


2020 ◽  
Vol 113 (6) ◽  
pp. 2595-2603
Author(s):  
Cesar A Reyes Corral ◽  
W Rodney Cooper ◽  
David R Horton ◽  
Alexander V Karasev

Abstract The potato psyllid, Bactericera cockerelli (Šulc), is a major pest of potato (Solanum tuberosum L.; Solanales: Solanaceae) as a vector of ‘Candidatus Liberibacter solanacearum’, the pathogen that causes zebra chip. Management of zebra chip is challenging in part because the noncrop sources of Liberibacter-infected psyllids arriving in potato remain unknown. Adding to this challenge is the occurrence of distinct genetic haplotypes of both potato psyllid and Liberibacter that differ in host range. Longleaf groundcherry (Physalis longifolia Nutt.) has been substantially overlooked in prior research as a potential noncrop source of Liberibacter-infected B. cockerelli colonizing fields of potato. The objective of this study was to assess the suitability of P. longifolia to the three common haplotypes of B. cockerelli (central, western, and northwestern haplotypes), and to two haplotypes of ‘Ca. L. solanacearum’ (Liberibacter A and B haplotypes). Greenhouse bioassays indicated that B. cockerelli of all three haplotypes produced more offspring on P. longifolia than on potato and preferred P. longifolia over potato during settling and egg-laying activities. Greenhouse and field trials showed that P. longifolia was also highly susceptible to Liberibacter. Additionally, we discovered that infected rhizomes survived winter and produced infected plants in late spring that could then be available for psyllid colonization and pathogen acquisition. Results show that P. longifolia is susceptible to both B. cockerelli and ‘Ca. L. solanacearum’ and must be considered as a potentially important source of infective B. cockerelli colonizing potato fields in the western United States.


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