The Role of Cutinsomes in Plant Cuticle Formation

Abstract

The cuticle commonly appears as a continuous lipophilic layer located at the outer epidermal cell walls of land plants. Cutin and waxes are its main components. Two methods for cutin synthesis are considered in plants. One that is based on enzymatic biosynthesis, in which cutin synthase (CUS) is involved, is well-known and commonly accepted. The other assumes the participation of specific nanostructures, cutinsomes, which are formed in physicochemical self-assembly processes from cutin precursors without enzyme involvement. Cutinsomes are formed in ground cytoplasm or, in some species, in specific cytoplasmic domains, lipotubuloid metabolons (LMs), and are most probably translocated via microtubules toward the cuticle-covered cell wall. Cutinsomes may additionally serve as platforms transporting cuticular enzymes. Presumably, cutinsomes enrich the cuticle in branched and cross-linked esterified polyhydroxy fatty acid oligomers, while CUS1 can provide both linear chains and branching cutin oligomers. These two systems of cuticle formation seem to co-operate on the surface of aboveground organs, as well as in the embryo and seed coat epidermis. This review focuses on the role that cutinsomes play in cuticle biosynthesis in S. lycopersicum, O. umbellatum and A. thaliana, which have been studied so far; however, these nanoparticles may be commonly involved in this process in different plants.

Sculpting the surface: Structural patterning of plant epidermis

“…We now have a good understanding of the biosynthetic pathways involved in the synthesis of the cuticle “building blocks” (reviewed in Fich et al., 2016 ; Leide et al., 2020 ; Lewandowska et al., 2020 , Table 1 ). Recent studies have also shed light on the mechanisms involved in the delivery and assembly of cuticular components ( Stępiński et al., 2020 , Table 1 ) as well as on the origins and evolution of associated pathways ( Kong et al., 2020 ; Leide et al., 2020 ; Li and Chang, 2021 ). However, the processes that sculpt the cuticle and give the plant epidermis its texture are not well understood.…”

Convergent evolution of disordered lipidic structural colour in the fruits of Lantana strigocamara (syn. L. camara hybrid cultivar)

“…Globules of cuticle material of various sizes are well known in the literature (e.g. Buda et al ., 2009; Martin & Rose, 2014; Domínguez et al ., 2017; Strępiński et al ., 2020), and modification of the quantity and organisation of such globules could serve as the developmental mechanism underlying the evolution of the photonic structure in L. strigocamara .…”

Structure, Assembly and Function of Cuticle from Mechanical Perspective with Special Focus on Perianth

“…Some authors postulate the involvement of so-called cutinsomes in the cuticle formation. These are lipid nanoparticles formed by the self-assembly of cutin monomers in water or polar aqueous solutions [ 40 , 56 , 57 ]. Lipid nanoparticles that were observed in the cytoplasm and in cell walls were referred to as cutinsomes.…”

“…Accordingly, cutinsome-based cutin assembly and enzyme-driven polymerization may function in sequence and contribute to various extents to cuticle formation at consecutive stages of organ development, as proposed for tomato fruit [ 58 ]. However, the contribution of cutinsome-based assembly in the formation of the procuticle and cuticle need to be further investigated [ 40 , 57 ].…”