Impact of Biocontrol Agents on Biochemical Changes of Aquatic Weed Water Hyacinth, Pontederia crassipes (Mart.) Solms-Laubach

Abstract

Invasive weeds are rapidly adapting to evolutionary changes, brought about by exposure to the plethora of plant-antagonist’s interactions, which eventually leave an effect on the biological control of the weed. These interactions create an array of biochemical responses in the plant, which induce a range of defensive mechanisms to reduce the threat of injury. The present investigation reports the role of plant secondary metabolites in plant defense that may involve deterrence of antifeedant activity associated with the application of biocontrol agents against Pontederia crassipes. Generally, an infestation is preferred on non-challenged plants, as increased content of alkaloid, phenol, or tannin, which Pontederia crassipes produces when infested by its agents, deters the latter by providing a toxic unpleasant atmosphere. Variation in flavonoid level also brings about some physiochemical changes in the weed which impede the entry of phytopathogens. When a few metabolites are used to dissuade the agents, some, like glycosides, attract feeders to lay eggs and allow their population to flourish. This study concentrates on the signals that enable P. crassipes to recognize and respond to the attack and measure the effect in biochemical terms. Through this has, an overall outlook of the fitness costs of attack not only for the weed but over the range of trophic levels has been enlightened with more scope to understand the underlying mechanisms, before the multi-agent release of agents.