ROS Metabolism Perturbation as an Element of Mode of Action of Allelochemicals

Abstract

The allelopathic interaction between plants is one of the elements that influences plant communities. It has been commonly studied by applying tissue extracts onto the acceptors or by treating them with isolated allelotoxins. Despite descriptive observations useful for agricultural practice, data describing the molecular mode of action of allelotoxins cannot be found. Due to the development of -omic techniques, we have an opportunity to investigate specific reactive oxygen species (ROS)-dependent changes in proteome or transcriptome that are induced by allelochemicals. The aim of our review is to summarize data on the ROS-induced modification in acceptor plants in response to allelopathic plants or isolated allelochemicals. We present the idea of how ROS are involved in the hormesis and plant autotoxicity phenomena. As an example of an -omic approach in studies of the mode of action of allelopatic compounds, we describe the influence of meta-tyrosine, an allelochemical exudated from roots of fescues, on nitration—one of nitro-oxidative posttranslational protein modification in the roots of tomato plants. We conclude that ROS overproduction and an induction of oxidative stress are general plants’ responses to various allelochemicals, thus modification in ROS metabolisms is regarded as an indirect mode of action of allelochemicals.

Autotoxicity in Panax notoginseng of root exudatesand their allelochemicals

“…The content of hydrogen peroxide, peroxidase activity, and malondialdehyde in the leaves of P. notoginseng cultured without the addition of activated carbon were all higher than those of the other, but the difference was not significant. It has been reported that allelochemicals can significantly reduce the enzyme activity of hydrogen peroxide and peroxide in tomato leaves ( Staszek et al., 2021 ). In this study, the allelochemicals had no significant effect on the enzyme activity, which may be due to the insufficient concentration of root exudates in the hydroponic environment.…”

Is the Phytotoxic Effect of Digestive Fluid of Nepenthes x ventrata on Tomato Related to Reactive Oxygen Species?

“…One of the first visible effects of phytotoxin’s action is the reduction of seed germination and/or seedling growth [ 28 ]. Diverse phytotoxins (like cyanamide, citral, coumarin) act as inhibitors of root tip cell division, influencing root growth [ 29 , 30 , 31 ]. Treatment of tomato seedlings with digestive fluids showed that components of these cocktails had no effect on the growth and development of the young seedlings.…”

“…They do not indicate a mechanism of their action [ 36 , 37 ]. In many studies, it has been demonstrated that, for allelopathy stress, as for other stresses, the induction of oxidative stress is the common response of acceptor plants [ 20 , 28 , 29 , 38 ]. Such observations are typical for both crude extracts of allelopathic plants, as well as for single allelopathic compounds.…”

Toxicity of meta-Tyrosine

“…The formation of 3-nitro-tyrosine (3-NT) occurs through the addition of a nitro group (-NO 2 ) in the ortho position of the Tyr ring via covalent binding [47]. Such modified, nitrated proteins lose their function [48,49]. There are no data indicating the possibility of the prevention of free p-Tyr nitration due to the m-Tyr formation.…”