RESUMO
Herbivorous insects use detoxification enzymes, including cytochrome P450 monooxygenases, glutathione S-transferases, and carboxy/cholinesterases, to metabolize otherwise deleterious plant secondary metabolites. Whereas Acyrthosiphon pisum (pea aphid) feeds almost exclusively from the Fabaceae, Myzus persicae (green peach aphid) feeds from hundreds of species in more than forty plant families. Therefore, M. persicae as a species would be exposed to a greater diversity of plant secondary metabolites than A. pisum, and has been predicted to require a larger complement of detoxification enzymes. A comparison of M. persicae cDNA and A. pisum genomic sequences is partially consistent with this hypothesis. There is evidence of at least 40% more cytochrome P450 genes in M. persicae than in A. pisum. In contrast, no major differences were found between the two species in the numbers of glutathione S-transferases, and carboxy/cholinesterases. However, given the incomplete M. persicae cDNA data set, the number of identified detoxification genes in this species is likely to be an underestimate.
Assuntos
Afídeos/enzimologia , Afídeos/genética , Genoma de Inseto , Sequência de Aminoácidos , Animais , Sequência de Bases , Biotransformação/genética , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Colinesterases/genética , Colinesterases/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Primers do DNA/genética , DNA Complementar/genética , Evolução Molecular , Etiquetas de Sequências Expressas , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Dados de Sequência Molecular , Pisum sativum/metabolismo , Pisum sativum/parasitologia , Filogenia , Prunus/metabolismo , Prunus/parasitologia , Homologia de Sequência de Aminoácidos , Especificidade da EspécieRESUMO
AIMS: To develop a novel, rapid and effective screening method for chitinase producing bacteria. METHODS AND RESULTS: A simple and rapid technique for screening of potential chitinolytic bacteria has been developed using the chitin binding dye calcofluor white M2R in chitin agar. Microorganisms possessing high chitinolytic potential gave a clear zone under ultraviolet light after 24-48 h of incubation. This method was successfully applied for isolating the hyperchitinase mutant of Alcaligenes xylosoxydans. The mutant Alc. xylosoxydans EMS 33 was found to produce 3.4 times more chitinase than the wild type. CONCLUSIONS: In this study, the screening method for chitinase producing bacteria has been developed and it was applied to screen chitinase-overproducing mutant of Alc. xylosoxydans. SIGNIFICANCE AND IMPACT OF THE STUDY: The novel screening method for chitinase producer is more sensitive, rapid, user-friendly and reliable, which can also be used for screening of recombinants having chitinase gene.
Assuntos
Alcaligenes/enzimologia , Bactérias/enzimologia , Técnicas Bacteriológicas , Quitina/metabolismo , Quitinases/metabolismo , Alcaligenes/genética , Alcaligenes/isolamento & purificação , Alcaligenes/efeitos da radiação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Benzenossulfonatos/química , Benzenossulfonatos/farmacologia , Quitina/química , Quitina/isolamento & purificação , Contagem de Colônia Microbiana , Mutação , Sensibilidade e EspecificidadeRESUMO
Alcaligenes xylosoxydans protected pigeonpea from Fusarium wilt in a pot experiment and field trials. When seeds of pigeonpea (C. cajan) were treated with A. xylosoxydans and sown in soil infested with Fusarium, the incidence of wilt was reduced by 43.5% and resulted in 58% higher grain yield. The antifungal activity of A. xylosoxydans was based on chitinase production and was comparable in efficacy to commercial antifungal agents such as benlate, monitor WP, thiram and bavistin.
