Molecular Mechanisms of Insecticide Resistance

Published on May 2017 | Categories: Documents | Downloads: 15 | Comments: 0 | Views: 189
of 11
Download PDF   Embed   Report

Comments

Content

MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
Johari Jalinas (P52191) MSc Entomology (Coursework)

INTRODUCTION
A

pesticide is any substance or mixture of substance intended for preventing, destroying, repelling or mitigating any pest. More than 500 different species of arthropods are resistant Pesticides used have led to the development of insecticide resistance. Development of insecticide resistance populations is a typical evolutionary process driven by survival of the fittest individuals.

GENERALIZED PROCESS OF INSECTICIDE
RESISTANCE DEVELOPMENT

OVERVIEW OF RESISTANCE MECHANIMS

The intoxication insecticide by the insect 1. Penetration of barrier tissues 2. Distribution, storage, and metabolism in internal tissues 3. Molecular interaction with the ultimate target site

Mutations that affect the rate constants of any these processes may reduce either the delivery of the ultimate toxicant to its target or the affinity of the toxicanttarget interaction

RESISTANCE MECHANISM
1. 2.

3.

Reduced cuticular penetration of toxicants Enhanced oxidative metabolism by cytochrome P450 dependent monooxygenases, hydrolases, or glutathione-S-transferases Reduced sensitivity of mutant acetlycholinesterases to Organaphosphate and Carbamate insecticides.

TARGET-SITE MECHANISMS
Alterations

of amino acids responsible for insecticide binding at its site of action cause the insecticide to be less effective or even ineffective.

Detoxification Mechanisms
The

enzymes responsible for detoxification of xenobiotics in living organisms are transcribed by members of large multigene families of esterases, oxidases, and GST

A. Single amino acid mutation in the IIS6 membrane-spanning region of the sodium channel gene that confers target-site DDT-pyrethroid resistance

B. Regulatory element allows induction of insecticide detoxifying oxidase and esterase resistance genes C.Esterase A2-B2 amplicon. These resistance esterase genes lie 5' end to 5' end within the same amplification unit

CONCLUSION
The

understanding of Molecular Mechanism of Insecticide Resistant is very important for the management of Insect Pests.

Thank You

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close