Biology subjects

Drevensek, S.

Publications and source records attributed to Drevensek, S..

5 recordsLinked to original sources

bioRxiv2025

Dual role of the receptor kinase FERONIA in regulating tissue mechanics and growth

During morphogenesis, growing organisms adapt to internal and external mechanical stress. In plants, the receptor kinase FERONIA is involved in a broad range of responses to perturbations of the cell wall, but it is unclear which cues are sensed and how this sensing controls growth. Here, we addressed these questions in Marchantia vegetative propagules. We combined culture in microfluidic chips to quantify growth and mechanical properties of propagules, perturbations with osmotic treatments, characterisation of cell wall polysaccharides, and a mathematical model of cell wall expansion that incorporates sensing. We found that FERONIA independently regulates tissue mechanical properties and growth rates. We propose that the regulation of growth by the FERONIA pathway relies on both a positive feedback from elastic deformation of the wall and a negative feedback from wall expansion. Altogether, we expect our quantitative framework to be broadly relevant to the investigation of how mechanical cues guide development.

plant biology↗

bioRxiv2024

Mechanical regulation of tissue flatness in Marchantia

The production of flat organs involves a tight regulation of tissue expansion. During growth, the cell wall is under mechanical tension and continuous remodelling, requiring mechanisms to sense and maintain cell wall integrity (CWI). Here we studied the link between CWI sensing and flatness of Marchantia polymorpha thalli. We considered FERONIA (FER), a CWI sensor, and assessed its role in the maintenance of thallus shape. We developed a pipeline to quantify flatness at multiple scales. We found that both abolishing and increasing FER expression leads to loss of flatness. Based on experiments that reduce cell wall tension and partially restore wild-type cell size and thallus morphology, we ascribe loss of flatness to under- or to over-reaction of plants to mechanical stress. Altogether, our results support the concept that responses to mechanical stress contribute to the robustness of morphogenesis

plant biology↗

bioRxiv2023

Assessing the link between tissue elasticity and plant growth

Multicellular organisms grow and acquire their shapes through the differential expansion and deformation of their cells. Recent research has addressed the role of cell and tissue mechanical properties in these processes. In plants, it is believed that growth rate is a function of the mechanical stress exerted on the cell wall, the thin polymeric layer surrounding cells, involving an effective viscosity. Nevertheless, recent studies have questioned this view, suggesting that cell wall elasticity sets growth rate or that uptake of water is limiting for plant growth. To assess these issues, we developed a microfluidic device to quantify growth rates, elastic properties, and hydraulic conductivity of individual Marchantia polymorpha plants in a controlled environment with a high throughput. We characterized the effect of osmotic treatment and of abscisic acid on growth and hydromechanical properties. Overall, the instantaneous growth rate of individuals is correlated to both bulk elastic modulus and hydraulic conductivity. Our results are consistent with a framework in which growth rate is determined primarily by elasticity of the wall and its remodelling, and secondarily by hydraulic conductivity. Accordingly, the coupling between chemistry of the cell wall and hydromechanics of the cell appears as key to set growth patterns during morphogenesis.

biophysics↗

bioRxiv2020

Study of the genetic and phenotypic variation among wild and cultivated clary sages provides interesting avenues for breeding programs of a perfume, medicinal and aromatic plant

A road-map of the genetic and phenotypic diversities in both crops and their wild-related species can help identifying valuable genetic resources for further crop breeding. The clary sage (Salvia sclarea L.), a perfume, medicinal and aromatic plant, is used for sclareol production and ornamental purposes. Despite its wide use in the field of cosmetics, the phenotypic and genetic diversity of wild and cultivated clary sage remains to be explored. We characterized the genetic and phenotypic variation of a collection of six wild S. sclarea populations from Croatia, sampled along an altitudinal gradient, and of populations of three S. sclarea cultivars. We showed low level of genetic diversity for the two S. sclarea traditional cultivars used for essential oil production and for ornamental purposes, respectively. In contrast, a recent cultivar resulting from new breeding methods, which involve hybridizations among several genotypes rather than traditional recurrent selection and self-crosses over time, showed high genetic diversity. We also observed a marked phenotypic differentiation for the ornamental clary sage compared with other cultivated and wild clary sages. Instead, the two cultivars used for essential oil production, a traditional and a recent, respectively, were not phenotypically differentiated from the wild Croatian populations. Our results also featured some wild populations with high sclareol content and early-flowering phenotypes as good candidates for future breeding programs. This study opens up perspectives for basic research aiming at understanding the impact of breeding methods on clary sage evolution, and highlights interesting avenues for clary breeding programs.

plant biology↗

bioRxiv2018

DET1-mediated degradation of a SAGA-like deubiquitination module controls H2Bub homeostasis

DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bub) over most genes by controlling the stability of a plant deubiquitination module (DUBm). In contrast with yeast and metazoan DUB modules that are associated with the large SAGA complex, the Arabidopsis DUBm only comprises three proteins (hereafter named SGF11, ENY2 and UBP22) and appears to act independently as a major H2Bub deubiquitinase activity. Our study further unveils that DET1-DDB1-Associated-1 (DDA1) protein interacts with SGF11 in vivo, linking the DET1 complex to light-dependent ubiquitin-mediated proteolytic degradation of the DUBm. Collectively, these findings uncover a signaling path controlling DUBm availability, potentially adjusting H2Bub turnover capacity to the cell transcriptional status.

plant biology↗