Shruti Ahlawat1, Deepti Singh1,2, Asha Yadav1, Amarjeet Kumar Singh3, Jugsharan Singh Virdi4, Krishna Kant Sharma5. 1. Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India. 2. Department of Microbiology, Amity University, Jaipur, India. 3. Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. 4. Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. 5. Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India. kekulsharma@gmail.com.
Abstract
OBJECTIVE: Earlier, we have found that the enteropathogenic Yersinia enterocolitica have evolved the survival mechanisms that regulate the expression of laccase-encoding genes in the gut. The present study aims to characterize the purified recombinant laccase from Y. enterocolitica strain 8081 biovar 1B and understand its effect on the midgut of cotton bollworm, Helicoverpa armigera (Hübner) larvae. RESULTS: The recombinant laccase protein showed high purity fold and low molecular mass (~ 43 kDa). H. armigera larvae fed with laccase protein showed a significant decrease in body weight and damage in the midgut. Further, transmission electron microscopy (TEM) studies revealed the negative effect of laccase protein on trachea, malpighian tubules, and villi of the insect. The proteome comparison between control and laccase-fed larvae of cotton bollworm showed significant expression of proteolytic enzymes, oxidoreductases, cytoskeletal proteins, ribosomal proteins; and proteins for citrate (TCA cycle) cycle, glycolysis, stress response, cell redox homeostasis, xenobiotic degradation, and insect defence. Moreover, it also resulted in the reduction of antioxidants, increased melanization (insect innate immune response), and enhanced free radical generation. CONCLUSIONS: All these data collectively suggest that H. armigera (Hübner) larvae can be used to study the effect of microbes and their metabolites on the host physiology, anatomy, and survival.
OBJECTIVE: Earlier, we have found that the enteropathogenic Yersinia enterocolitica have evolved the survival mechanisms that regulate the expression of laccase-encoding genes in the gut. The present study aims to characterize the purified recombinant laccase from Y. enterocolitica strain 8081 biovar 1B and understand its effect on the midgut of cotton bollworm, Helicoverpa armigera (Hübner) larvae. RESULTS: The recombinant laccase protein showed high purity fold and low molecular mass (~ 43 kDa). H. armigera larvae fed with laccase protein showed a significant decrease in body weight and damage in the midgut. Further, transmission electron microscopy (TEM) studies revealed the negative effect of laccase protein on trachea, malpighian tubules, and villi of the insect. The proteome comparison between control and laccase-fed larvae of cotton bollworm showed significant expression of proteolytic enzymes, oxidoreductases, cytoskeletal proteins, ribosomal proteins; and proteins for citrate (TCA cycle) cycle, glycolysis, stress response, cell redox homeostasis, xenobiotic degradation, and insect defence. Moreover, it also resulted in the reduction of antioxidants, increased melanization (insect innate immune response), and enhanced free radical generation. CONCLUSIONS: All these data collectively suggest that H. armigera (Hübner) larvae can be used to study the effect of microbes and their metabolites on the host physiology, anatomy, and survival.
Authors: Maud E S Achard; Jai J Tree; James A Holden; Kim R Simpfendorfer; Odilia L C Wijburg; Richard A Strugnell; Mark A Schembri; Matthew J Sweet; Michael P Jennings; Alastair G McEwan Journal: Infect Immun Date: 2010-03-15 Impact factor: 3.441