Transcriptomics and interactomics during the primary infection of an SfNPV baculovirus on larvae.

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.

The chitin-binding domain of Bacillus thuringiensis ChiA74 inhibits gram-negative bacterial and fungal pathogens of humans and plants.

The chitinase ChiA74 is synthesized by Bacillus thuringiensis and possesses a modular organization composed of four domains. In the C-terminal of the enzyme is located the chitin-binding domain (CBD), which has not been isolated as a single unit or characterized. Here, we aimed to isolate the ChiA74's CBD as a single unit, determine the binding properties, and evaluate its antimicrobial and hemolytic activities.

Biological, morphological, and molecular characterization of the baculovirus PlxyMNPV_LBIV-11, and its virulence towards Plutella xylostella, Trichoplusia ni, and Spodoptera frugiperda larvae.

PlxyMNPV_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.

Molecular and Toxicological Characterization of a Bacillus thuringiensis Strain Expressing a Vip3 Protein Highly Toxic to Spodoptera frugiperda (Lepidoptera: Noctuidae).

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.

Virulence and genetic characterization of six baculovirus strains isolated from different populations of Spodoptera frugiperda (Lepidoptera: Noctuidae).

Fall 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.

Use of RNAi as a preliminary tool for screening putative receptors of nematicidal toxins from Bacillus thuringiensis.

Bacillus 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.

Expression of ChiA74∆sp and its truncated versions in Bacillus thuringiensis HD1 using a vegetative promoter maintains the integrity and toxicity of native Cry1A toxins.

Our objective was to determine whether a recombinant chitinase ChiA74∆sp of Bacillus thuringiensis and its truncated versions (ChiA74∆sp-60, ChiA74∆sp-50) could be produced in B. thuringiensis HD1 with no detrimental effect on the size and insecticidal activity of the native bipyramidal Cry crystal. chiA-p, the promoter used to drive chitinase gene expression, was active during vegetative growth of CryB.

High Virulence of Mexican Entomopathogenic Fungi Against Fall Armyworm, (Lepidoptera: Noctuidae).

Fourteen 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.

Characterization of a highly toxic strain of Bacillus thuringiensis serovar kurstaki very similar to the HD-73 strain.

The 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.

Bacillus thuringiensis subsp. kurstaki HD1 as a factory to synthesize alkali-labile ChiA74∆sp chitinase inclusions, Cry crystals and spores for applied use.

Background: The endochitinase ChiA74 is a soluble secreted enzyme produced by Bacillus thuringiensis that synergizes the entomotoxigenecity of Cry proteins that accumulate as intracellular crystalline inclusion during sporulation. The purpose of this study was to produce alkaline-soluble ChiA74∆sp inclusions in B. thuringiensis, and to determine its effect on Cry crystal production, sporulation and toxicity to an important agronomical insect, Manduca sexta.

Infection, transfection, and co-transfection of baculoviruses by microprojectile bombardment of larvae.

The use of baculoviruses as expression vectors for heterologous proteins has been practically limited to the use of the Autographa californica multiple nucleopolyhedrovirus (AcMNPV). In this work, infection, transfection and co-transfection events with the baculoviruses AcMNPV and Trichoplusia ni granulovirus (TnGV) were accomplished by bombardment of T. ni first-instar larvae with microprojectiles coated with virions, viral DNA, and viral DNA and a transfer vector, respectively.