Although the spectrum of effective methods and techniques that allow determination of inorganic or total phosphorus is impressive, more precise analysis of these substances in plant tissues is not a routine or trivial task. The complexity of chemical composition of plant tissues treated as the analytical matrices is thought to be the main cause why there is no one answer, how appropriate phosphorus compounds may be determined qualitatively and quantitatively. Even if more advanced spectrophotometric measurements and classical variants of absorption (FAAS) or emission (ICP-AES/ ICP-OES) spectrometry techniques are used, it is necessary at first to isolate various forms of phosphorus from the matrix, and then to mineralize them prior the determination. Significant progress in such a kind of analytical efforts was brought by implementation of combined methods e.g. ETV-ICP-AES or HR-ETAAS, does allow the isolation of the phosphorus analyte and its detection during a kind of “one step” analytical procedure, directly in plant tissues. Similar benefits, regarding sensitivity of determinations, are obtained when XRF, SIMS or nanoSIMS—more expensive techniques of imaging the presence of phosphorus in biological matrices have been used. Nowadays, obviously being aware of higher limit of detection, nuclear magnetic resonance spectroscopy, especially the 31P NMR technique, is thought to be the most universal analytical tool allowing to determine various chemical forms of plant phosphorus qualitatively and quantitatively, at the same time. Although 31P NMR provides valuable information about the phosphorus profile of plants, it should be emphasized that each analytical issue related to the determination of phosphorus compounds in plant tissues and organs, requires an individual approach to defined problem.

To verify the hypothesis that cyanobacteria naturally biosynthesising polyphenolic compounds possess an active enzymatic system that enables them to transform these substances, such an ability of the biocatalytic systems of whole cells of these biota was assessed for the first time. One halophilic strain and seven freshwater strains of cyanobacteria representing four of the five taxonomic orders of Cyanophyta were examined to determine the following: (i) whether they contain polyphenols, including flavonoids; (ii) the resistance of their cultures when suppressed by the presence of exogenous hydroxychalcones—precursors of flavonoid biosynthesis and (iii) whether these photoautotrophs can transform hydroxylated chalcones. All examined strains were found to contain polyphenols and flavonoids, and the growth of their cultures was inhibited in the presence of 2′-hydroxychalcone, 2″-hydroxychalcone and 4″-hydroxychalcone. We also confirmed that the examined cyanobacteria transformed hydroxychalcones via hydrogenative bio-reduction and formed the corresponding hydroxydihydro derivatives with yields above 90% whenever the substrates were bioavailable for such a conversion. Moreover, we observed that the routes and efficiency of biohydrogenation (and hydroxylation) of chalcones were dependent on the location of the hydroxyl substituent. The final products obtained as the results of biotransformations were extracted from the media and identified by mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (1H NMR, 13C NMR, COSY, HSQC). Based on those results, we believe that the very efficient biohydrogenation of hydroxychalcones, which may easy be scaled up for biotechnological purposes, reflects the natural activity of the cyanobacterial defence system, because hydroxydihydrochalcones were less active inhibitors of the growth of cyanobacterial cultures than the corresponding substrates.

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Cyanobacteria, also known as blue-green (micro)algae, are able to sustain many types of chemical stress because of metabolic adaptations that allow them to survive and successfully compete in a variety of ecosystems, including polluted ones. As photoautotrophic bacteria, these microorganisms synthesize aromatic amino acids, which are precursors for a large variety of substances that contain aromatic ring(s) and that are naturally formed in the cells of these organisms. Hence, the transformation of aromatic secondary metabolites by cyanobacteria is the result of the possession of a suitable “enzymatic apparatus” to carry out the biosynthesis of these compounds according to cellular requirements. Another crucial aspect that should be evaluated using varied criteria is the response of cyanobacteria to the presence of extracellular aromatic compounds. Some aspects of the relationship between aromatic compounds and cyanobacteria such as the biosynthesis of aromatic compounds, the influence of aromatic compounds on these organisms and the fate of aromatic substances inside microalgal cells are presented in this paper. The search for this information has suggested that there is a lack of knowledge about the regulation of the biosynthesis of aromatic substances and about the transport of these compounds into cyanobacterial cells. These aspects are of pivotal importance with regard to the biotransformation of aromatic compounds and understanding them may be the goals of future research.

Phosphorus is one of the most important elements essential for all living beings. Plants accumulate and store phosphorous in various forms that have diverse physiological and biochemical functions. In this study,we determine and then examine the phosphorus profiles of seeds of plants belonging to different taxa based on extractable inorganic phosphates and organic forms of phosphorus. We paid particular attention to the presence of natural phosphonates in the tested materials. The inorganic phosphates were determined colorimetrically, whereas phosphorus profiles were created by using 31P NMR spectroscopy. Our study on phosphorus profiles revealed that the obtainedsets of data vary significantly among the representatives of different taxa and were somehow specific for families of plants. It should be emphasised that the measurements obtained using 31P NMR spectroscopy undoubtedly confirmed—for the first time—the presence of phosphonates among the natural components of plant seeds. Hence, the classification of plants considering the phosphorus profiles, including the presence of phosphonates, may be a new additional chemotaxonomic feature.

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A convenient and general reaction is presented for the preparation of diaminophosphonates further evaluated as chelators of metal ions.

Cucumber is one of the most commonly produced vegetable crops. The greatest economic losses in the yields of these crops have resulted from fungal infections—powdery mildew and downy mildew. The action of fungicides not only affects the fungi, but can also lead to metabolic disorders in plants. However, some fungicides have been reported to have positive physiological effects. Our research focused on the action of two commercially available fungicides, Scorpion 325 SC and Magnicur Finito 687,5 SC, on plant metabolism. Two approaches were used to check the effect of the fungicides at the early stage of plant development when metabolic changes occur most dynamically: spraying on the leaves of cucumber seedlings and presowing seed treatment. The application of the fungicide formulation as a presowing seed treatment caused perturbations in the phytase activity, leading to disorders in the energetic status of the germinating seeds. In addition, the tested preparations changed the morphology of the germinating seeds, limiting the growth of the stem. Furthermore, the application of the tested fungicides on seedlings also showed a disruption in the energetic status and in the antioxidative system. Therefore, the use of pesticides as agents causes a “green effect” and requires a much deeper understanding of plant metabolism.