Toxic proteins in plants

Abstract

Plants have evolved to synthesize a variety of noxious compounds to cope with unfavorable circumstances, among which a large group of toxic proteins that play a critical role in plant defense against predators and microbes. Up to now, a wide range of harmful proteins have been discovered in different plants, including lectins, ribosome-inactivating proteins, protease inhibitors, ureases, arcelins, antimicrobial peptides and pore-forming toxins. To fulfill their role in plant defense, these proteins exhibit various degrees of toxicity towards animals, insects, bacteria or fungi. Numerous studies have been carried out to investigate the toxic effects and mode of action of these plant proteins in order to explore their possible applications. Indeed, because of their biological activities, toxic plant proteins are also considered as potentially useful tools in crop protection and in biomedical applications, such as cancer treatment. Genes encoding toxic plant proteins have been introduced into crop genomes using genetic engineering technology in order to increase the plant's resistance against pathogens and diseases. Despite the availability of ample information on toxic plant proteins, very few publications have attempted to summarize the research progress made during the last decades. This review focuses on the diversity of toxic plant proteins in view of their toxicity as well as their mode of action. Furthermore, an outlook towards the biological role(s) of these proteins and their potential applications is discussed.

Exploiting the biological roles of the trypsin inhibitor from Inga vera seeds: A multifunctional Kunitz inhibitor

“…Plant peptidase inhibitors (PIs) are widely distributed in plant tissues, especially in seeds and tubers [1]. They play an essential role in plant development due to their modulation of peptidase activities that are normally involved in important physiological processes [2,3].…”

“…They play an essential role in plant development due to their modulation of peptidase activities that are normally involved in important physiological processes [2,3]. They might also be associated with plant defense mechanisms, by protecting them against insects and pathogens [1,4].…”

“…PIs exhibit a wide range of biological activities that has attracted much interest mainly because of their potential applications in agriculture and medicine [1,5]. As multifaceted molecules, they have been studied for improvement of plant resistance to pathogens and insects [4,[6][7][8], antimicrobial agent [9,10] and anticancer agent [11][12][13][14].…”

Oxidant effects and toxicity ofCroton campestrisinDrosophila melanogaster

“…To cope with those unfavourable conditions plants have undergone adaptations such as the elaboration of defence strategies synthesizing bioactive compounds. Some of them are potentially toxic such as alkaloids, terpenoids, tannins and glycosides (Dang et al 2015;Maag et al 2015).…”

Insights into the Molecular Antiviral Mechanism of Pokeweed Protein from Phytolacca americana

“…Many plants have evolved to produce natural defense mechanisms that aid in the battle with foreign pathogenic invaders. Plant defense mechanisms include myriad physical and chemical defenses, which prevent pathogens from entering the plant cell, limit their availability, and/or restrict the nutrients necessary for the growth and replication of the pathogen [4][5][6][7][8].…”