Mariya Ptashnyk

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Hairy roots are plants genetically transformed by Agrobacterium rhizogenes, which do not produce shoots and are composed mainly by roots. Hairy roots of Ophiorrhiza mungos Linn. are currently gaining interest of pharmacologists, since a secondary product of their metabolism, camptothecin, is used in chemotherapy. To optimize the production of valuable(More)
Root hairs are known to be important in the uptake of sparingly soluble nutrients by plants, but quantitative understanding of their role in this is weak. This limits, for example, the breeding of more nutrient-efficient crop genotypes. We developed a mathematical model of nutrient transport and uptake in the root hair zone of single roots growing in soil(More)
Combining different theoretical approaches, curvature modulated sorting in lipid bilayers fixed on non-planar surfaces is investigated. First, we present a continuous model of lateral membrane dynamics, described by a nonlinear PDE of fourth order. We then prove the existence and uniqueness of solutions of the presented model and simulate membrane dynamics(More)
Water flow in plant tissues takes place in two different physical domains separated by semiper-meable membranes: cell insides and cell walls. The assembly of all cell insides and cell walls are termed symplast and apoplast, respectively. Water transport is pressure driven in both, where osmosis plays an essential role in membrane crossing. In this paper, a(More)
sn this —rti™le we ™onsider derive — m—™ros™opi™ model for root length density evoE lutionD st—rting from — dis™rete mesh of rootsD using homogeniz—tionF sn the mi™ros™opi™ model e—™h roots grows verti™—lly —™™ording to —n ordin—ry di'erenti—l equ—tionF „he roots growth r—tes depend on the sp—ti—l rep—rtition of nutrient in the soilD whi™h —lso evolves in(More)
Regulation of zinc uptake in roots of Arabidopsis thaliana has recently been modeled by a system of ordinary differential equations based on the uptake of zinc, expression of a transporter protein and the interaction between an activator and inhibitor. For certain parameter choices the steady state of this model becomes unstable upon variation in the(More)
Major research efforts are targeting the improved performance of root systems for more efficient use of water and nutrients by crops. However, characterizing root system architecture (RSA) is challenging, because roots are difficult objects to observe and analyse. A model-based analysis of RSA traits from phenotyping image data is presented. The model can(More)
The microscopic structure and anisotropy of plant cell walls greatly influence the mechanical properties, morphogenesis, and growth of plant cells and tissues. The microscopic structure and properties of cell walls are determined by the orientation and mechanical properties of the cellulose microfibrils and the mechanical properties of the cell wall matrix.(More)
" Multiscale modelling and analysis of mechanical properties of plant cells and tissues " PhD external examiner: Derivation of a macroscopic model for transport of strongly sorbed solutes in the soil using homogenization theory, SIAM Model of diffusion of strongly-sorbed solutes through soil allowing for slow access to and from sorption sites and(More)
It is known that the orientation of cellulose microfibrils within plant cell walls has an important impact on the morphogenesis of plant cells and tissues. Viewing the shape of a plant cell as a square prism or cylinder with the axis aligning with the primary direction of expansion and growth, the orientation of the microfibrils within the cell wall on the(More)