The Accumulation of Volatile Compounds and the Change in the Morphology of the Leaf Wax Cover Accompanied the "Anti-Aging" Effect in Anethum graveolens L. Plants Sprayed with 6-Benzylaminopurine.

Essential oils (EOs) are of commercial importance for medicine, food, cosmetics, the perfume industry, and agriculture. In plants, EOs, like the wax cover, serve as protection against abiotic stresses, such as high temperatures and water deficiency. The use of spraying with exogenous hormones of aromatic plants affects the accumulation and composition of volatile compounds, as well as tolerance to abiotic stress. As a result of cytokinin treatment with 6-BAP (6-benzylaminopurine) (200 mg L-l) of Anetum graveolens L. "Uzory" and "Rusich" varieties, several responses to its action were revealed: a change in the division of leaf blades, inhibition of flowering, an increase in the content of EO and its main components α-phellandrene and p-cymene in leaves, and limonene in umbels and fruits. It was revealed that the increased accumulation of EO in dill leaves was longer with sufficient moisture. In contrast, under conditions of heat and water deficiency, the effect of 6-BAP treatment on accumulations of the EO in leaves was short-lived and did not appear on umbels and fruits. The study of the cytokinin effect on a fine structure of a wax cover on the adaxial side of leaves by scanning electron microscopy revealed a change in its elements (from amorphous layers with scales to thin tubules), which probably increased the sensitivity of leaves to water deficiency and, consequently, led to a decrease in the biosynthetic activity of leaf tissue. Thus, 6-BAP had an impact on the adaptive properties of dill plants, prolonging the "youth" of vegetative organs and the ability to EO biosynthesis under conditions of sufficient moisture.

Bacterial Communities of Lamiacea L. Medicinal Plants: Structural Features and Rhizosphere Effect.

Bacterial communities associated with medicinal plants are an essential part of ecosystems. The rhizosphere effect is rather important in the cultivation process. The purpose of the study was to analyze the rhizosphere effect of oregano (Origanum vulgare L.), peppermint (Mentha piperita L.), thyme (Thymus vulgaris L.), creeping thyme (Thymus serpillum L.) and sage (Salvia officinalis L.). To estimate the quantity of 16S bacteria ribosomal genes, qPCR assays were used. To compare bacterial communities' structure of medicinal plants rhizosphere with bulk soil high-throughput sequencing of the 16S rRNA targeting variable regions V3-V4 of bacteria was carried out. The highest bacterial abundance was associated with T. vulgaris L., M. piperita L. and S. officinalis L., and the lowest was associated with the O. vulgare L. rhizosphere. Phylum Actinobacteriota was predominant in all rhizosphere samples. The maximum bacterial α-diversity was found in S. officinalis L. rhizosphere. According to bacterial ß-diversity calculated by the Bray-Curtis metric, T. vulgaris L. root zone significantly differed from bulk soil. The rhizosphere effect was positive to the Myxococcota, Bacteroidota, Verrucomicrobiota, Proteobacteria and Gemmatimonadota.