Plant-insect interactions mechanisms

It is possible that these ecoregulatory enzymes, used by the insect to inhibit targeted plant toxlficatlon systems, may themselves be the principal target of the production of tannins by plants. The discovery of other examples of secondary chemical interactions with enzymes dedicated to the regulation of toxifica-tion and detoxification mechanisms may be expected as our knowledge of chemically mediated plant-insect interaction expands. 

The role of calystegines in plants has not been elucidated, but the fact that they appear in a limited number of species indicates that they might be a source of carbon and nitrogen to soil bacteria that benefit the rhizosphere of the plant [5, 25]. Calystegines may also play a role in plant defence mechanisms and plant-insect interactions as reported by Nash [10]. 

The functions of phenylpropanoid derivatives are as diverse as their structural variations. Phenylpropanoids serve as phytoalexins, UV protectants, insect repellents, flower pigments, and signal molecules for plant-microbe interactions. They also function as polymeric constituents of support and surface structures such as lignins and suberins [1]. Therefore, biosynthesis of phenylpropanoids has received much interest in relation to these functions. In addition, the biosynthesis of these compounds has been intensively studied because they are often chiral, and naturally occurring samples of these compounds are usually optically active. Elucidation of these enantioselective mechanisms may contribute to the development of novel biomimetic systems for enantioselective organic synthesis. 

A. Structure-Effect Relations between Calystegines and Glycosidases Mechanism of Inhibition Toxicology of Calystegines Possible Medicinal Applications Activity of Calystegines in Plants A. Plant Rhizosphere Allelopathic Activity Insect Feeding Repellent Activity Anti-Nematode Activity Plant-Fungi Interactions... 

The automatic measurement of the extracellular and intracellular electrical potential difference can be effectively used in plant electrophysiology for studying the molecular interfacial mechanisms of ion transport, the influence of external stimuli on plants, and for investigating the bioelectrochemical aspects of the interaction between insects and plants. 

There are naturally-occurring opioid agonists from plants, such as morphine, which owes its dramatic psychopharmacological effects in mammals to an interaction with receptors for enkephalins and endorphins. As evidence increases that insects and other arthropods utilize neuroactive peptides as neuromessengers (16), it becomes more likely that some of the plant opiates are defensive chemicals having a "psychomanipulant" type of mechanism. 

A unique role is played by chemical communication in the interactions between plants and insects. About half a million insect species feed on plants. The process of reproduction in many plant species is critically dependent upon pollination by insects. It is not surprising, then, to find among the numerous natural products of plants both attractants for useful insects and repellents or even insecticides for plant-eating insects. The remarkable diversity of the these compounds (the list includes acyclic and polycyclic compounds, isoprenoids, aromatic derivatives, heterocyclic compounds, etc.) illustrates the non-selectivity in the structure of the chemical mediators for biological applications. The intimate mechanism of their action is, unfortunately, still insufficiently understood. 

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