LysM domain-containing chitinases in pteridophytes: A promising resource for sustainable biopesticides.

Chitinases are hydrolytic enzymes that catalyse the degradation of chitin, a major component of fungal cell walls and arthropod exoskeletons. Although extensively studied in higher plants, chitinases in pteridophytes remain largely unknown. This review examined the potential of pteridophyte chitinases as a promising resource for advanced biopesticides. Pteridophytes, including ferns and lycophytes, dating back over 450 million years, have evolved unique adaptations to terrestrial environments, suggesting they may possess novel chitinase variants. Research on fern chitinases, particularly in Pteris ryukyuensis and Equisetum arvense, has revealed distinct features, such as LysM domains, which enhance chitin-binding and antifungal activity. PrChi-A chitinase from P. ryukyuensis exhibits remarkable thermal stability and specific binding to chitin oligosaccharides, which could be advantageous for agricultural applications. Additionally, engineered multimeric LysM domains fused with catalytic domains have demonstrated enhanced antifungal effects compared to those of naturally occurring chitinases. These findings highlight the potential of pteridophyte chitinases in developing improved biopesticides against fungal pathogens. The unique evolutionary position of pteridophytes among non-vascular and seed plants suggests they may harbour additional novel chitinase variants with diverse biochemical properties. Further exploration of chitinases across various pteridophyte species could uncover enzymes with enhanced stability, specificity, and efficacy for sustainable agriculture and biotechnology. This review highlights the need for increased research on pteridophyte chitinases to harness their potential as valuable resources for cutting-edge biopesticides and other biotechnological applications.