Chapter 3 - Bacterial cyclodipeptides in triggers plant immunity potential

Abstract

Cyclodipeptides (CDPs) are unusual in terms of simplicity of their structure, universality of occurrence, and versatility of interaction. CDPs formed from two amino acids via cyclodehydration are produced by many organisms and possess a large number of biological activities: antibacterial, antifungal, antiviral, and anticancer as well as are cytotoxic and phytotoxic. Diffusible CDPs, being signaling substances in communication interfere often between very distant phylogenetic organisms in a specific crosstalk. CDPs produced by microorganisms from the kingdoms of Prokaryota and Fungi as well as Protista interact with the microbiological quorum-sensing (QS) system and the signaling substances as QS N-Acyl-l-homoserine lactone interact with phytohormonal and plant immunity pathways. While the role of CDPs in regulating processes in animal systems is quite thoroughly understood, their involvement in the regulation of plant processes is still little studied and documented. It appears that microbial CDPs commonly present in the plant growth environment consistently induce plant resistance under natural conditions. There is much to explain in the functioning of CDPs as elicitors of plant resistance to phytopathogens and abiotic factors and the possibilities of their application in biological protection and biostimulation of plant growth. CDPs produced by bacteria inhabiting the rhizosphere and plant tissues seem to be particularly important in understanding the establishment of the microbiome–plant relationship and the possibility of application thereof. Detailed knowledge of the methods of obtaining bacterial CDPs and the mechanisms of their influence on plants will allow to develop new efficient methods of plant protection and understand the basics of interactions.