UTTAR PRADESH JOURNAL OF ZOOLOGY

Plants are sedentary living organisms performing vivid roles in life cycle from germination to reproduction. During this journey they encounter several distinct obstacles right from the exposure to various unsuitable climatic conditions, to unwanted attackers such as insects, pathogens or even the manmade chemicals. Though the plants are motionless and inactive in appearance often they wisely defend themselves. Majority of the insects depend on plants for their feeding, oviposition and sometimes whole survival itself. Plants when attacked by an insect or a pathogen, respond to resist the intrusion in its life and overcome it in several ways. Plant chemicals and hormones are important shielding molecules present in them that stimulate responses against herbivores. Plants utilize cost effective methods to administer its energy for either growth or defense against insect feeding. They defend themselves utilizing the plant variability of primary metabolites, secondary metabolites, alkaloids and plant enzymes that detoxify the reactive oxygen species. Thus they have either antinutritive or antidigestive effects that play a major role in inhibiting the invasion of insects. These mechanisms help plants defend themselves from feeding insector animal attack and this area of research is gaining interest in scientific community of late.