Molecular and insecticidal characterization of a novel Cry-related protein from Bacillus thuringiensis toxic against Myzus persicae

• Published in: Toxins 2014-11, Vol.6 (11), p.3144-3156
• Main Authors: Palma, Leopoldo, Muñoz, Delia, Berry, Colin, Murillo, Jesús, de Escudero, Iñigo Ruiz, Caballero, Primitivo
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Animals; Aphididae; Aphids - growth & development; Bacillus thuringiensis; Bacillus thuringiensis - metabolism; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Base Sequence; Biological control; Conserved Sequence; Cry-related protein; Gene Expression Regulation, Bacterial; green peach aphid; Helicoverpa armigera; Homoptera; Insecticides - chemistry; Insecticides - metabolism; Insects; Lepidoptera; Lethal Dose 50; Mamestra brassicae; Molecular Weight; Myzus persicae; Noctuidae; Nymph; parasporins; Pest Control, Biological - methods; Phylogeny; Protein Structure, Tertiary; Prunus; Receptors, Cell Surface - chemistry; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Analysis, DNA; Sequence Homology; Spodoptera exigua; δ-endotoxins
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins6113144

This study describes the insecticidal activity of a novel Bacillus thuringiensis Cry-related protein with a deduced 799 amino acid sequence (~89 kDa) and ~19% pairwise identity to the 95-kDa-aphidicidal protein (sequence number 204) from patent US 8318900 and ~40% pairwise identity to the cancer cell killing Cry proteins (parasporins Cry41Ab1 and Cry41Aa1), respectively. This novel Cry-related protein contained the five conserved amino acid blocks and the three conserved domains commonly found in 3-domain Cry proteins. The protein exhibited toxic activity against the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae) with the lowest mean lethal concentration (LC₅₀ = 32.7 μg/mL) reported to date for a given Cry protein and this insect species, whereas it had no lethal toxicity against the Lepidoptera of the family Noctuidae Helicoverpa armigera (Hübner), Mamestra brassicae (L.), Spodoptera exigua (Hübner), S. frugiperda (J.E. Smith) and S. littoralis (Boisduval), at concentrations as high as ~3.5 μg/cm². This novel Cry-related protein may become a promising environmentally friendly tool for the biological control of M. persicae and possibly also for other sap sucking insect pests.