Abstract
The review presents data on the role of leaf epidermis, lignin, and its monolignols in the adaptation of higher plants to adverse environmental conditions. It discusses the localization and content of syringyl monolignin and guajacyl monolignin in cell walls and how they affect the elasticity of plant cell walls under different natural conditions. These data are presented using modern methods of laser scanning confocal microscopy, and scanning electron microscopy. The review also discusses literature data and the results of our own experimental studies on the cellular mechanisms of lignin synthesis and its regulation, as well as the participation of monolignols in plant adaptation to environmental changes. It shows the role of monolignols in regulating water balance and transpiration of plants, as well as in protecting plant cells from abiotic stresses and environmental changes. Recent studies have also shown the influence of lignin on the expression of genes involved in the synthesis of secondary cell walls and metabolites with protective properties. This review indicates the potential for further research into the role of monolignols and confirms that the conservation of species characterized by increased lignin synthesis may be a conceptual basis for the protection and conservation of flora from abiotic stresses.