Brassinosteroids (BRs) are plant hormones of steroid nature, regulating various developmental and adaptive processes. The perception, transport, and signaling of BRs are actively studied nowadays via a wide range of biochemical and genetic tools. However, most of the knowledge about BRs intracellular localization and turnover relies on the visualization of the receptors or cellular compartments using dyes or fluorescent protein fusions. We have previously synthesized a conjugate of epibrassinolide with green fluorescent dye BODIPY (eBL-BODIPY). Here we present a detailed assessment of the compound bioactivity and its suitability as probe for in vivo visualization of BRs. We show that eBL-BODIPY rapidly penetrates epidermal cells of Arabidopsis thaliana roots and after long exposure causes physiological and transcriptomic responses similar to the natural hormone.

• Klíčová slova
• brassinosteroids, fluorescent conjugates, live imaging, plant bioassay,
• MeSH
• Arabidopsis metabolismus   MeSH
• brassinosteroidy chemie   metabolismus   MeSH
• fluorescenční barviva chemie   MeSH
• kořeny rostlin metabolismus   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• signální transdukce MeSH
• sloučeniny boru chemie   MeSH
• steroidy heterocyklické chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene MeSH Prohlížeč
• brassinolide MeSH Prohlížeč
• brassinosteroidy MeSH
• fluorescenční barviva MeSH
• regulátory růstu rostlin MeSH
• sloučeniny boru MeSH
• steroidy heterocyklické MeSH

Brassinosteroids are a class of plant hormones that regulate a broad range of physiological processes such as plant growth, development and immunity, including the suppression of biotic and abiotic stresses. In this paper, we report the synthesis of new brassinosteroid analogues with a nitrogen-containing side chain and their biological activity on Arabidopis thaliana. Based on molecular docking experiments, two groups of brassinosteroid analogues were prepared with short and long side chains in order to study the impact of side chain length on plants. The derivatives with a short side chain were prepared with amide, amine and ammonium functional groups. The derivatives with a long side chain were synthesized using amide and ammonium functional groups. A total of 25 new brassinosteroid analogues were prepared. All 25 compounds were tested in an Arabidopsis root sensitivity bioassay and cytotoxicity screening. The synthesized substances showed no significant inhibitory activity compared to natural 24-epibrassinolide. In contrast, in low concentration, several compounds (8a, 8b, 8e, 16e, 22a and 22e) showed interesting growth-promoting activity. The cytotoxicity assay showed no toxicity of the prepared compounds on cancer and normal cell lines.

• Klíčová slova
• brassinosteroid, cytotoxicity, nitrogen-containing steroid, organic synthesis, plant bioassay,
• MeSH
• Arabidopsis účinky léků   růst a vývoj   MeSH
• brassinosteroidy chemická syntéza   chemie   farmakologie   MeSH
• dusík chemie   MeSH
• molekulární struktura MeSH
• techniky syntetické chemie * MeSH
• vývoj rostlin účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• brassinosteroidy MeSH
• dusík MeSH

Auxins mediate various processes that are involved in plant growth and development in response to specific environmental conditions. Its proper spatio-temporal distribution that is driven by polar auxin transport machinery plays a crucial role in the wide range of auxins physiological effects. Numbers of approaches have been developed to either directly or indirectly monitor auxin distribution in vivo in order to elucidate the basis of its precise regulation. Herein, we provide an updated list of valuable techniques used for monitoring auxins in plants, with their utilities and limitations. Because the spatial and temporal resolutions of the presented approaches are different, their combination may provide a comprehensive outcome of auxin distribution in diverse developmental processes.

• Klíčová slova
• auxin, auxin distribution, auxin signalling, auxin transport, direct visualization, indirect visualization, receptor, sensor,
• MeSH
• Arabidopsis metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• vývoj rostlin fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• kyseliny indoloctové MeSH

Like thapsigargin, which is undergoing clinical trials, trilobolide is a natural product with promising anticancer and anti-inflammatory properties. Similar to thapsigargin, it has limited aqueous solubility that strongly reduces its potential medicinal applications. The targeted delivery of hydrophobic drugs can be achieved using liposome-based carriers. Therefore, we designed a traceable liposomal drug delivery system for trilobolide. The fluorescent green-emitting dye BODIPY, cholesterol and trilobolide were used to create construct 6. The liposomes were composed of dipalmitoyl-3-trimethylammoniumpropane and phosphatidylethanolamine. The whole system was characterized by atomic force microscopy, the average size of the liposomes was 150 nm in width and 30 nm in height. We evaluated the biological activity of construct 6 and its liposomal formulation, both of which showed immunomodulatory properties in primary rat macrophages. The uptake and intracellular distribution of construct 6 and its liposomal formulation was monitored by means of live-cell fluorescence microscopy in two cancer cell lines. The encapsulation of construct 6 into the liposomes improved the drug distribution in cancer cells and was followed by cell death. This new liposomal trilobolide derivative not only retains the biological properties of pure trilobolide, but also enhances the bioavailability, and thus has potential for the use in theranostic applications.

• Klíčová slova
• BODIPY conjugates, cancer targeting, drug delivery, liposomes, natural compounds, sesquiterpene lactone trilobolide,
• Publikační typ
• časopisecké články MeSH