Vol 8 Issue 3 May 2021-June 2021
Worku Abebe
Abstract: As primary producers, plants are under constant pressure to defend themselves against potentially deadly pathogens and herbivores. Insects pose a great threat to plants and plants in turn, withstand to insect attack through a wide diversity of defensive mechanisms. Interactions between plants and insect herbivores are important determinants of plant productivity in agriculture. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Plant characters that confer herbivore resistance prevent or reduce herbivore damage through expression of characters that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability.
Plant defensive mechanisms are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. Plant defense mechanisms against insect herbivores are broadly categorized into direct and indirect defense mechanisms. Direct defense is involved both physical and biochemical barriers which synergistically obstruct insect herbivore’s growth, development, reproduction, etc. The indirect defense mechanisms have no direct impact on insect herbivores but suppress pests by releasing volatile compounds that attract natural enemies of the herbivores. Overall categories of direct plant defenses against insect herbivores include limiting food supply, reducing nutrient value, reducing preference, disrupting physical structures, and inhibiting chemical pathways of the attacking insect. Major known defense chemicals include plant secondary metabolites, protein inhibitors of insect digestive enzymes, proteases, lectins, amino acid deaminases and oxidases. In this review, the two broad categories of plant defense mechanisms against insect pests: direct and indirect defense mechanisms have been widely discussed.
Keywords: Insect pests, Herbivory, Plant defence, direct defense, structural defense, biochemical defense, indirect defense, natural enemy.
Title: REVIEW ON PLANT DEFENSE MECHANISMS AGAINST INSECT PESTS
Author: Worku Abebe
ISSN 2394-9716
International Journal of Novel Research in Interdisciplinary Studies
Novelty Journals