We have developed and validated a novel LC-MS/MS method for simultaneously analyzing amino acids, biogenic amines, and their acetylated and methylated derivatives in plants. This method involves a one-step extraction of 2-5 mg of lyophilized plant material followed by fractionation of different biogenic amine forms, and exploits an efficient combination of hydrophilic interaction liquid chromatography (HILIC), reversed phase (RP) chromatography with pre-column derivatization, and tandem mass spectrometry (MS). This approach enables high-throughput processing of plant samples, significantly reducing the time needed for analysis and its cost. We also present a new synthetic route for deuterium-labeled polyamines. The LC-MS/MS method was rigorously validated by quantifying levels of nitrogen-related metabolites in seedlings of seven plant species, including Arabidopsis, maize, and barley, all of which are commonly used model organisms in plant science research. Our results revealed substantial variations in the abundance of these metabolites between species, developmental stages, and growth conditions, particularly for the acetylated and methylated derivatives and the various polyamine fractions. However, the biological relevance of these plant metabolites is currently unclear. Overall, this work contributes significantly to plant science by providing a powerful analytical tool and setting the stage for future investigations into the functions of these nitrogen-related metabolites in plants.

• Keywords
• Acetylated amino acids, LC-MS/MS, acetylated biogenic amines, amino acids, biogenic amines, methylated amino acids, plant metabolism,
• MeSH
• Arabidopsis metabolism   growth & development   MeSH
• Chromatography, Liquid MeSH
• Nitrogen * metabolism   MeSH
• Hordeum metabolism   growth & development   MeSH
• Liquid Chromatography-Mass Spectrometry MeSH
• Zea mays metabolism   growth & development   MeSH
• Polyamines metabolism   analysis   MeSH
• Plants metabolism   MeSH
• Tandem Mass Spectrometry * methods   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Nitrogen * MeSH
• Polyamines MeSH

This study aimed to point out the possible use of oak leaves (Q. petraea) in the production of fermented alcoholic beverages. Parameters such as antioxidant capacity, total phenolic content, phenolics and sugars were determined using spectrophotometric and chromatographic methods. pH values were also determined, and in the final product with a fermentation length of 85 days, the alcohol content was determined and sensory analysis performed. The antioxidant capacity of the beverage was lower compared to the infusions before fermentation, and its highest values were recorded in the leaf samples, in which the highest values of phenolic compounds and the total phenolic content were also recorded. A decrease in the content of total phenolics was recorded with the increasing length of fermentation in beverage samples. However, the fermentation process had a positive effect on the contents of some phenolic substances such as catechin, gallic acid and gallocatechin. Sensory analysis showed a higher acceptability of the fermented beverage without the addition of orange, which could be caused by the higher sugar content in these samples. Oak leaves therefore represent a suitable raw material for the production of a fermented alcoholic beverage, without the need to enrich the taste with other ingredients.

• Keywords
• Quercus, alcoholic beverages, antioxidant capacity, fermentation, oak leaves, polyphenols,
• Publication type
• Journal Article MeSH

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.

• Keywords
• amino acids, chemical profiling, glucosinolates, indoor cultivation, liquid chromatography, radish, sugars,
• Publication type
• Journal Article MeSH

Biostimulants became a hotspot in the fight to alleviate the consequences of abiotic stresses in crops. Due to their complex nature, it is challenging to obtain stable and reproducible final products and more challenging to define their mechanism of action. As an alternative, small molecule-based biostimulants, such as polyamines have promoted plant growth and improved stress tolerance. However, profound research about their mechanisms of action is still missing. To go further, we tested the effect of putrescine (Put) and its precursor ornithine (Orn) and degradation product 1,3-diaminopropane (DAP) at two different concentrations (0.1 and 1 mM) as a seed priming on in vitro Arabidopsis seedlings grown under optimal growth conditions, osmotic or salt stress. None of the primings affected the growth of the seedlings in optimal conditions but altered the metabolism of the plants. Under stress conditions, almost all primed plants grew better and improved their greenness. Only Orn-primed plants showed different plant responses. Interestingly, the metabolic analysis revealed the implication of the N- acetylornithine and Orn and polyamine conjugation as the leading player regulating growth and development under control and stress conditions. We corroborated polyamines as very powerful small molecule-based biostimulants to alleviate the adverse abiotic stress effects.

• Keywords
• abiotic stress, biostimulant, growth, plant phenotyping,
• Publication type
• Journal Article MeSH