New Horizons in Insect Science Towards Sustainable Pest Management

179

Molecular Approaches for

the Improvement of Bacillus

thuringiensis Against Pests

Ankit Patel, Leena Pathak, Noushad Parvez, Deepak

Panpatte, Kuldeep Khatri and Janardan Jani

A. K. Chakravarthy (ed.), New Horizons in Insect Science: Towards Sustainable Pest Management,
DOI 10.1007/978-81-322-2089-3_17, © Springer India 2015

A. Patel () · L. Pathak · N. Parvez · D. Panpatte ·
K. Khatri · J. Jani
Biological Control Research Laboratory, Anand Agricul-
tural University, Anand, Gujarat, 388110 India
e-mail: [email protected]

Abstract

Multiple pest management tools including biological approaches, are gen-

erally recognized as possible solutions. Bacillus thuringiensis (Bt) Berliner

has been used as a biopesticide in agriculture. The insecticidal properties

of this bacterium are due to insecticidal proteins. Genetic improvement of

Bt natural strains, in particular Bt recombination, offers a promising means

of improving efficacy and cost-effectiveness of Bt-based bioinsecticide

products to develop new biotechnological applications; which describes

site-specific recombination, including transposition and transduction. Ap-

plications of homologous recombination include disruption of cry and cyt

genes to assess their contribution to pesticidal activity and inactivation

of protease producing genes to increase crystal production and stability.

Conjugation-like system is used to transfer cry encoding plasmids within

strains but most cry genes are not readily transmissible by this process.

Nevertheless, a number of transconjugant and naturally occurring strains

producing Cry proteins distinct from those of Bt HD-1 subsp. kurstaki,

including strains of Bt subsp. aizawai and Bt subsp. morrisoni, have been

registered with Environmental Protection Agency (EPA). Engineering Bt

and B. cereus came in 1989 through electroporation to transform vegeta-

tive cells with plasmid DNA. Genes conferring resistance to insects have

been inserted into crop plants.

Keywords

Bacillus thuringiensis · Molecular approaches · Pest · Resistance

Introduction

Since World War II, control methods of insect

disease have relied heavily on broad-spectrum

synthetic chemical insecticides. However, many