(Bt) is a Gram-positive bacterium that forms spores and produces parasporal crystalline inclusions containing Cry and Cyt proteins [...
View Article and Find Full Text PDFFront Cell Infect Microbiol
December 2023
The fall armyworm (FAW), , has been the most devastating pest of corn as well as of other crops in America, and more recently in Africa and Asia. The development of resistance to chemical insecticides led the search for environmentally friendly biological alternatives such as baculoviruses. This study focuses on the primary infection of the baculovirus SfNPV-Ar in the FAW's midgut epithelium, by analyzing the differential expression of transcripts in excised midguts at 6, 12, and 24 h post-infection (hpi), and predicted their interactions.
View Article and Find Full Text PDFFruit flies (Diptera: Tephritidae) are serious pests that affect fruit production and marketing. Both third instar larvae and pupae are biological stages that persist in the soil until adult emergence. Entomopathogenic nematodes (ENs) are biological control agents that are used to control agricultural pests in greenhouse or field conditions.
View Article and Find Full Text PDFDespite the fact that Bacillus thuringiensis is the most widely used bacterium in biological pest control, its ecology has been notoriously neglected. Its role in nature is uncertain, and a defined habitat and niche are under discussion. In this report, wild-type strains were isolated from the inner plant tissues as natural endophytic bacteria in wild plants.
View Article and Find Full Text PDFPlxyMNPV_LBIV-11 is an alphabaculovirus strain, isolated from Plutella xylostella larvae. This work characterized this strain at a biological, morphological, and molecular level to evaluate its similarity with other baculoviruses. Its ultrastructure showed a multiple arrangement of nucleocapsids within enveloped virions, all occluded within large cubical polyhedra.
View Article and Find Full Text PDFJ Econ Entomol
October 2022
The characterization of the Bacillus thuringiensis (Berliner) LBIT-418 strain was based on a previous work which indicated its high insecticidal potential. Therefore, toxicological, molecular, and biochemical characterizations were conducted in this work to identify its unique features and its potential to be developed as a bioinsecticide. This strain, originally isolated from a healthy mosquito larva, was identified within the subspecies kenyae by sequencing of the hag gene and by the multilocus sequence typing (MLST) technique.
View Article and Find Full Text PDFFall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States.
View Article and Find Full Text PDFspp. are tropical plants used for brewing beverages from roasted and grounded seeds, the favorite drink in the world. It is the most important commercial crop plant and the second most valuable international commodity after oil.
View Article and Find Full Text PDFAntonie Van Leeuwenhoek
November 2021
Bacillus thuringiensis is the most successful microbial insecticide against different pests in agriculture and vectors of diseases. Its activity is mostly attributed to the Cry proteins expressed during its sporulation phase. However, these proteins are not exclusive to B.
View Article and Find Full Text PDFRecent discovery of endophytic strains of Bacillus thuringiensis significantly improves the knowledge on its ecology. It also may be a new source for the isolation of insecticidal strains. This report shows the characterization of two endophytic, highly insecticidal strains of B.
View Article and Find Full Text PDFSomatic embryogenesis (SE) is the most important plant biotechnology process for plant regeneration, propagation, genetic transformation and genome editing of coffee, Coffea arabica L. Somatic embryo (SEs) conversion to plantlets is the principal bottleneck for basic and applied use of this process. In this study we focus on the maturation of SEs of C.
View Article and Find Full Text PDFBacillus thuringiensis has been widely used as a biological control agent against insect pests. Additionally, nematicidal strains have been under investigation. In this report, 310 native strains of B.
View Article and Find Full Text PDFBacillus thuringiensis is a potential control agent for plant-parasitic nematodes. Nematode intestinal receptors for Cry21-type toxins are poorly known. Therefore, a strategy was tested as a primary screening tool to find possible Cry toxin receptors, using a nematicidal Bt strain and the RNAi technique on Caenorhabditis elegans.
View Article and Find Full Text PDFIn this report, physical and chemical properties, and total arsenic (As) concentrations were analyzed in agricultural (MASE) and mining soils (SMI) in the State of Guanajuato, México. Additionally, a metagenomic analysis of both types of soils was the bases for the identification and selection of bacteria and fungi resistant to As. The SMI soil showed higher concentration of As (39 mg kg) as compared to MASE soil (15 mg kg).
View Article and Find Full Text PDFThe Cry1C protein family of Bacillus thuringiensis form bipyramidal crystals, which are commonly associated with toxic activity against lepidopteran species; however, some members of this family may also be toxic to dipterans. In the present work, the Cry1Ca16 protein, synthesized by the B. thuringiensis LBIT-1217 strain, was analyzed.
View Article and Find Full Text PDFThis report presents an efficient protocol of the stable genetic transformation of coffee plants expressing the Cry10Aa protein of . Embryogenic cell lines with a high potential of propagation, somatic embryo maturation, and germination were used. Gene expression analysis of cytokinin signaling, homedomains, auxin responsive factor, and the master regulators of somatic embryogenesis genes involved in somatic embryo maturation were evaluated.
View Article and Find Full Text PDFThis report focuses on a systematic search for Cry proteins in spp. other than by analyzing reported spp. genomes, using conserved sequences from the C-terminal half of reported Cry proteins in hidden Markov model profiles.
View Article and Find Full Text PDFFourteen fungal entomopathogenic strains were isolated from soil samples and infected field-collected fall armyworm larvae, in Guanajuato, Mexico. Isolates were identified by morphology and internal transcribed spacers sequencing. Isolates Ma22, Ma41, and Mr8 showed 99% identity with reference strains (RS) of Metarhizium anisopliae.
View Article and Find Full Text PDFThe complete genome of a Trichoplusia ni granulovirus (TnGV) is described and analyzed. The genome contains 175,360 bp (KU752557), becoming the third largest genome within the genus Betabaculovirus, smaller only than the Xestia c-nigrum GV (XecnGV) (178,733 pb) and the Pseudaletia unipuncta GV (PsunGV) (176,677 pb) genomes. The TnGV genome has a 39.
View Article and Find Full Text PDFThe LBIT-1200 strain of Bacillus thuringiensis was recently isolated from soil, and showed a 6.4 and 9.5 increase in toxicity, against Manduca sexta and Trichoplusia ni, respectively, compared to HD-73.
View Article and Find Full Text PDFBacillus thuringiensis Cry toxins exert their toxic effect by specific recognition of larval midgut proteins leading to oligomerization of the toxin, membrane insertion and pore formation. The exposed domain II loop regions of Cry toxins have been shown to be involved in receptor binding. Insect cadherins have shown to be functionally involved in toxin binding facilitating toxin oligomerization.
View Article and Find Full Text PDFBacillus thuringiensis (Bt) is a soil-dwelling bacterium of great interest for agronomical research because of its use as biological pesticide. There are some limitations regarding the subspecies classification. Phenotyping and genotyping studies are important to ascertain its variability.
View Article and Find Full Text PDFSix strains of Bacillus thuringiensis previously selected as highly toxic against Manduca sexta and Plutella xylostella were analyzed by PCR screening in order to identify the cry genes active on Lepidoptera. According to their gene content and insecticidal potency, these strains were cultured and aliquots taken at different pre- and post-sporulation times. Total RNA was extracted and used as template in RT-PCR analyses directed to identify mRNAs of the previously identified cry genes.
View Article and Find Full Text PDFBacillus thuringiensis Cry1AbMod toxins are engineered versions of Cry1Ab that lack the amino-terminal end, including domain I helix α-1 and part of helix α-2. This deletion improves oligomerization of these toxins in solution in the absence of cadherin receptor and counters resistance to Cry1A toxins in different lepidopteran insects, suggesting that oligomerization plays a major role in their toxicity. However, Cry1AbMod toxins are toxic to Escherichia coli cells, since the cry1A promoter that drives its expression in B.
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