Optimizing growing conditions for hydroponic farming of selected medicinal and aromatic plants

Profiling of Health-Promoting and Taste-Relevant Compounds in Sixteen Radish (Raphanus sativus L.) Genotypes Grown under Controlled Conditions

It is becoming increasingly challenging to maintain crop yields and quality as the global climate changes. The aim of this study was to determine whether and how the profile of health-promoting and taste-related compounds of radishes changes within a growing season. A total of 16 radish (Raphanus sativus L.) genotypes that are commercially available on the Czech market were assessed by means of chemical analysis. Radishes were cultivated in three independent growing cycles under controlled conditions, and the effects of the genotype and growing cycle, as well as their interactions, on the chemical traits were evaluated. Most of the variability in chemical composition was associated with the growing cycle, which accounted for 51.53% of total variance, followed by the genotype (26% of total variance). The interaction between the growing cycle and genotype explained 22.47% of total variance. The growing cycle had the strongest effect on amino acid profiles. More specifically, the amino acids that are known to contribute to overall taste (glycine, along with glutamic and aspartic acids) showed the highest degree of variation, while the amino acids related to glucosinolate biosynthesis (methionine, isoleucine, tryptophan, and phenylalanine) showed relatively low variability. On the other hand, indole glucosinolates were found to differ the most between genotypes.

Biochemical and structural basis of polyamine, lysine and ornithine acetylation catalyzed by spermine/spermidine N-acetyl transferase in moss and maize

Polyamines such as spermidine and spermine are essential regulators of cell growth, differentiation, maintenance of ion balance and abiotic stress tolerance. Their levels are controlled by the spermidine/spermine N¹ -acetyltransferase (SSAT) via acetylation to promote either their degradation or export outside the cell as shown in mammals. Plant genomes contain at least one gene coding for SSAT (also named NATA for N-AcetylTransferase Activity). Combining kinetics, HPLC-MS and crystallography, we show that three plant SSATs, one from the lower plant moss Physcomitrium patens and two from the higher plant Zea mays, acetylate various aliphatic polyamines and two amino acids lysine (Lys) and ornithine (Orn). Thus, plant SSATs exhibit a broad substrate specificity, unlike more specific human SSATs (hSSATs) as hSSAT1 targets polyamines, whereas hSSAT2 acetylates Lys and thiaLys. The crystal structures of two PpSSAT ternary complexes, one with Lys and CoA, the other with acetyl-CoA and polyethylene glycol (mimicking spermine), reveal a different binding mode for polyamine versus amino acid substrates accompanied by structural rearrangements of both the coenzyme and the enzyme. Two arginine residues, unique among plant SSATs, hold the carboxyl group of amino acid substrates. The most abundant acetylated compound accumulated in moss was N⁶ -acetyl-Lys, whereas N⁵ -acetyl-Orn, known to be toxic for aphids, was found in maize. Both plant species contain very low levels of acetylated polyamines. The present study provides a detailed biochemical and structural basis of plant SSAT enzymes that can acetylate a wide range of substrates and likely play various roles in planta.

Evaluation of Halophyte Biopotential as an Unused Natural Resource: The Case of Lobularia maritima

Halophytes are plant species widely distributed in saline habitats, such as beaches, postindustrial wastelands, irrigated lands, salt flats, and others. Excessive salt level, known to limit plant growth, is not harmful to halophytes, which have developed a variety of defense mechanisms allowing them to colonize harsh environments. Plants under stress are known to respond with several morpho-anatomical adaptations, but also to enhance the production of secondary metabolites to better cope with difficult conditions. Owing to these adaptations, halophytes are an interesting group of undemanding plants with a high potential for application in the food and pharmaceutical industries. Therefore, this review aims to present the characteristics of halophytes, describe changes in their gene expression, and discuss their synthesized metabolites of pharmacognostic and pharmacological significance. Lobularia maritima is characterized as a widely spread halophyte that has been shown to exhibit various pharmacological properties in vitro and in vivo. It is concluded that halophytes may become important sources of natural products for the treatment of various ailments and for supplementing the human diet with necessary non-nutrients and minerals. However, extensive studies are needed to deepen the knowledge of their biological potential in vivo, so that they can be introduced to the pharmaceutical and food industries.