Abstract
Chitosan (CTS) is a biodegradable and biocompatible biopolymer derived from chitin. Thanks to its diverse biological activities and environmentally friendly nature, it has emerged as a promising agent in plant tissue culture. Recent studies have highlighted its role as a natural elicitor that can enhance plant growth, seed germination, and the biosynthesis of secondary metabolites in vitro. In plant tissue culture, it acts as a biotic elicitor, mimicking a pathogen attack and activating the pathogenesis-related proteins to induce secondary metabolite production. In vitro tissue culture is a scientifically meaningful and cost-effective approach to testing the elicitation mechanisms of various abiotic elicitors, including CTS. However, the methodology of CTS elicitation in plant tissue cultures is not straightforward or uniform due to the differences in the CTS origin, molecular weight, and degree of deacetylation, all of which directly affect solubility. This review summarizes the methodological approaches to the use of CTS in plant tissue culture elicitation and highlights specific features of these procedures.