Biology subjects

Domozych, D. S.

Publications and source records attributed to Domozych, D. S..

3 recordsLinked to original sources

bioRxiv2025

Spatiotemporal variation in cutin polymerization and remodeling mediated by GDSL-hydrolase enzymes during tomato fruit development

Land plants produce a cuticle, an extracellular hydrophobic layer that covers aerial organs and is involved in many critical protective roles, most notably in preventing desiccation. The predominant component of the cuticle is the lipidic polyester, cutin, which is deposited in the epidermal primary cell wall. Most of cutin of tomato fruit, a model for cuticle research, is polymerized by the extracellular GDSL-hydrolase enzyme CUTIN SYNTHASE-LIKE 1 (CUS1). However, other enzymes involved in cutin assembly remain to be identified and characterized. In this current study, we investigated whether other GDSL-hydrolases that are highly expressed in fruit epidermis might also contribute to cutin polymerization and restructuring. Candidates include homologs of Arabidopsis thaliana CUTICLE DESTRUCTIVE FACTOR 1 (CDEF1), which has been reported to catalyze cutin hydrolysis, as well as other phylogenetically diverse and distantly related GDSL-hydrolases. We determined that members of the CUS and CDEF families can catalyze the transesterification of cutin precursors in vitro, and can modify tomato fruit cutin structure in semi-in vivo assays. Tomato mutant knockout lines of CUS and CDEF genes generated by CRISPR/Cas9 and cross mutations with cus1 (previously cd1) were found to exhibit different fruit and flower phenotypes related to cutin assembly, including an effect on cutin monomer esterification, composition and content, cutin nanoridge formation in flowers, fruit cuticle permeability and permeance. Characterization of the mutant phenotypes, in combination with the enzyme analysis and bioassays, revealed distinct differences in the contribution of CUS and CDEF enzymes to cutin biosynthesis and remodeling. Our analysis also revealed unexpected spatiotemporal variation in cutin polymerization and structure coordinated by distinct GDSL-hydrolase enzymes over the fruit surface, which further suggests great complexity in cutin deposition and cuticle functions during organ development. HighlightsO_LICutin polymerization in tomato is catalyzed by coordinating the spatiotemporal expression of CUTIN SYNTHASE enzymes in different organs, including during fruit development. C_LIO_LIExtracellular cutin polymerization is not a function limited to the canonical CUTIN SYNTHASE family members but can be also be catalyzed by other GDSL-hydrolase enzymes, as suggested by evidence in vitro. C_LIO_LITomato CDEF enzymes, a clade within the GDSL-hydrolase superfamily, are involved in remodeling cutin structure during fruit development. C_LIO_LIThe biosynthesis and remodeling of cutin over the tomato fruit surface is spatially heterogeneous. C_LI

plant biology↗

bioRxiv2020

Callose deposition is essential for the completion of cytokinesis in the unicellular alga Penium margaritaceum

Cytokinesis in land plants involves the formation of a cell plate that develops into the new cell wall. Callose is a {beta}-1,3 glucan that transiently accumulates at later stages of cell plate development and is thought to stabilize the delicate membrane network of the cell plate as it expands. Cytokinetic callose deposition is currently considered specific to multicellular plant species as it has not been detected in unicellular algae. Here we present callose at the cytokinesis junction of the unicellular charophyte, Penium margaritaceum. Notably, callose deposition at the division plane of P. margaritaceum showed distinct, spatiotemporal patterns that could represent distinct roles of this polymer in cytokinesis and cell wall assembly. Pharmacological inhibition of cytokinetic callose deposition by Endosidin 7 treatment resulted in cytokinesis defects, consistent with the essential role for this polymer in P. margaritaceum cell division. Cell wall deposition and assembly at the isthmus zone was also affected by the absence of callose, demonstrating the dynamic nature of new wall assembly in P. margaritaceum. The identification of candidate callose synthase genes provides molecular evidence for callose biosynthesis in P. margaritaceum. The evolutionary implications of cytokinetic callose in this unicellular Zygnematopycean alga is discussed in the context of the conquest of land by plants. Summary StatementEvolutionarily conserved callose in Penium margaritaceum is essential for the completion of cytokinesis.

cell biology↗

bioRxiv2019

The Genome of the Charophyte Alga Penium margaritaceum Bears Footprints of the Evolutionary Origins of Land Plants

The colonization of land by plants was a pivotal event in the history of the biosphere, and yet the underlying evolutionary features and innovations of the first land plant ancestors are not well understood. Here we present the genome sequence of the unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The P. margaritaceum genome has a high proportion of repeat sequences, which are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with earlier diverging plant lineages, P. margaritaceum has uniquely expanded repertoires of gene families, signaling networks and adaptive responses, supporting its phylogenetic placement and highlighting the evolutionary trajectory towards terrestrialization. These encompass a broad range of physiological processes and cellular structures, such as large families of extracellular polymer biosynthetic and modifying enzymes involved in cell wall assembly and remodeling. Transcriptome profiling of cells exposed to conditions that are common in terrestrial habitats, namely high light and desiccation, further elucidated key adaptations to the semi-aquatic ecosystems that are home to the Zygnematophyceae. Such habitats, in which a simpler body plan would be advantageous, likely provided the evolutionary crucible in which selective pressures shaped the transition to land. Earlier diverging charophyte lineages that are characterized by more complex land plant-like anatomies have either remained exclusively aquatic, or developed alternative life styles that allow periods of desiccation.

plant biology↗