Do nanoparticles delivered to roots affect plant secondary metabolism? A comprehensive analysis in float seedling cultures of Hypericum perforatum L.

Since nanoparticles (NPs) released into the environment from household or industrial wastes and applied directly on plants as agrochemicals can accumulate in the rhizosphere, it is imperative to understand how these NPs affect plant secondary metabolism upon their contact with the roots of intact plants. Here, the effects of Pd, Au, ZnO and Fe2O3 NPs on secondary metabolism were comprehensively investigated in Hypericum perforatum L float seedlings by analyzing 41 major secondary metabolites using ultra-performance liquid chromatography coupled with photodiode array, fluorescence detector and high-resolution mass spectrometry (UPLC-PDA-FLR-HRMS). The results showed that exposure of H. perforatum roots to Pd, Au, ZnO and Fe2O3 NPs rapidly led to fluctuations in the levels of secondary metabolites. Although these fluctuations did not correlate with NP type, concentration and duration of treatment, a total of 22 compounds were significantly altered by the NPs tested. In particular, 1 ppm Au increased the content of quercetin 3-(2″-acetylgalactoside), cadensin G and leutoskyrin by 5.02-, 2.12- and 2.58-fold, respectively after 24 h; 25 ppm Pd NPs led to a 2.1-fold increase in miquelianin content after 6 h; 50 ppm Fe2O3 NPs increased the level of furohyperforin by 3.09-fold and decreased the content of miquelianin 5.22-fold after 24 h and 50 ppm ZnO led to a 2.13-fold increase in hypericin after 48 h. These results emphasise the need to understand the intricate interplay between NPs and plant secondary metabolism in order to enable safer and efficient applications of NPs in agriculture.

Single molecule real-time sequencing data sets of Hypericum perforatum L. plantlets and cell suspension cultures.

Hypericum is a large genus that includes more than 500 species of pharmacological, ecological and conservation value. Although latest advances in sequencing technologies were extremely exploited for generating and assembling genomes of many living organisms, annotated whole genome sequence data is not publicly available for any of the Hypericum species so far. Bioavailability of secondary metabolites varies for different tissues and the data derived from different cultures will be a valuable tool for comparative studies. Here, we report the single molecule real-time sequencing (SMRT) data sets of Hypericum perforatum L. plantlets and cell suspension cultures for the first time. Sequencing data from cell suspension cultures yielded more than 33,000 high-quality transcripts from 20 Gb of raw data, while more than 55,000 high-quality transcripts were obtained from 35 Gb of raw data from plantlets. This dataset is a valuable tool for comparative transcriptomic analysis and will help to understand the unknown biosynthetic pathways of high medicinal value in the Hypericum genus.

Suitability of Adenosine Derivatives in Improving the Activity and Stability of Cytochrome c under Stress: Insights into the Effect of Phosphate Groups.

It is well known that adenosine and its phosphate derivatives play a crucial role in biological phenomena such as apoptosis and cell signaling and act as the energy currency of the cell. Although their interactions with various proteins and enzymes have been described, the focus of this work is to demonstrate the effect of the phosphate group on the activity and stability of the native heme metalloprotein cytochrome c (Cyt c), which is important from both biological and industrial aspects. In situ and in silico characterizations are used to correlate the relationship between the binding affinity of adenosine and its phosphate groups with unfolding behavior, corresponding peroxidase activities, and stability factors. Interaction of adenosine (ADN), adenosine monophosphate (AMP), adenosine 5'-diphosphate (ADP), and adenosine 5'-triphosphate (ATP) with Cyt c increases peroxidase-like activity by up to 1.8-6.5-fold compared to native Cyt c. This activity is significantly maintained even after multiple stress conditions such as oxidative stress and the presence of a chaotropic agent such as guanidine hydrochloride (GuHCl). With binding affinities on the order of ADN < AMP < ADP < ATP, adenosine derivatives were found to stabilize Cyt c by varying the secondary structural features of the protein. Thus, in addition to being a fundamental study, the current work also proposes a way of stabilizing protein systems to be used for real-time biocatalytic applications.

Unveiling Dissolution Kinetics of CuO Nanofertilizer Using Bio-Based Ionic Liquids Envisaging Controlled Use Efficiency for Sustainable Agriculture.

The need for sustainable agriculture amid a growing population and challenging climatic conditions is hindered by the environmental repercussions of widespread fertilizer use, resulting in the accumulation of metal ions and the loss of micronutrients. The present study provides an approach to improve the efficiency of nanofertilizers by controlling the release of copper (Cu) ions from copper oxide (CuO) nanofertilizers through bioionic liquids based on plant growth regulators (PGR-ILs). A 7-day study was conducted to understand the kinetics of Cu ion release in aqueous solution of five different PGR-ILs, with choline ascorbate ([Cho][Asc]) or choline salicylate ([Cho][Sal]) leading to 200- to 700-fold higher dissolution of Cu ions in comparison to choline indole-3-acetate ([Cho][IAA]), choline indole-3-butyrate ([Cho][IBA]), and choline gibberellate ([Cho][GA3]). The tunable diffusion of Cu ions from CuO nanofertilizers using PGR-ILs is then applied in a foliar spray study, evaluating its impact on the growth phenotype, photosynthetic parameters, and carbon dioxide (CO2) sequestration in Nicotiana tabacum in a greenhouse. The results indicate that nanoformulations with lower concentrations of Cu ions in PGR-IL solutions exhibit superior outcomes in terms of plant length, net photosynthetic rate, dry biomass yield, and CO2 sequestration, emphasizing the critical role of dissolution kinetics in determining the effectiveness of PGR-IL-based nanoformulations for sustainable agriculture.