PADAPT 1.0 - the Pannonian Dataset of Plant Traits.

The existing plant trait databases' applicability is limited for studies dealing with the flora and vegetation of the eastern and central part of Europe and for large-scale comparisons across regions, mostly because their geographical data coverage is limited and they incorporate records from several different sources, often from regions with markedly different climatic conditions. These problems motivated the compilation of a regional dataset for the flora of the Pannonian region (Eastern Central Europe). PADAPT, the Pannonian Dataset of Plant Traits relies on regional data sources and collates data on 54 traits and attributes of the plant species of the Pannonian region. The current version covers approximately 90% of the species of the region and consists of 126,337 records on 2745 taxa. By including species of the eastern part of Europe not covered by other databases, PADAPT can facilitate studying the flora and vegetation of the eastern part of the continent. Although data coverage is far from complete, PADAPT meets the longstanding need for a regional database of the Pannonian flora.

Vegetation Dynamics in a Loess Grassland: Plant Traits Indicate Stability Based on Species Presence, but Directional Change When Cover Is Considered.

This article evaluates the three-year vegetation dynamics of a species rich, protected steppe grassland on loess where no grazing occurred for decades at Bicske, Central Hungary. A detailed coenological survey of vascular vegetation was conducted in four permanent plots of 16 m2 each from 2018 to 2020. Raunkiaer's life-forms, distribution range, and thousand-seed weight of species were evaluated. Shannon diversity and turnover rates for the species and the vegetation were also determined for each plot. In total, 108 vascular plant species were detected. The results indicate grassland stability when plant traits spectra were based on species presence data, but directional change if species cover values were used to weight trait categories. During the three years of the study, chamaephytes decreased and woody species increased their contribution for the Raunkiaer's life-forms, while the cosmopolitan group has steadily lost its significance for distribution range types. Shannon diversity varied between 2.46 and 3.18 among plots (based on natural logarithm) and remained statistically unchanged through time. Average species turnover rates were 14.18% for 2018/19 and 17.52% for 2019/20, whereas corresponding values for vegetation turnover rates were 25.83% and 23.28%. Vegetation turnover rate was significantly higher than the species turnover rate.

Goldenrod Root Compounds Active against Crop Pathogenic Fungi.

Root extracts of three goldenrods were screened for antimicrobial compounds. 2Z,8Z- and 2E,8Z-matricaria esters from European goldenrod (Solidago virgaurea) and E- and Z-dehydromatricaria esters from grass-leaved goldenrod (Solidago graminifolia) and first from showy goldenrod (Solidago speciosa) were identified by high-performance thin-layer chromatography combined with effect-directed analysis and high-resolution mass spectrometry or nuclear magnetic resonance spectroscopy after liquid chromatographic fractionation and isolation. Next to their antibacterial effects (against Bacillus subtilis, Aliivibrio fischeri, and Pseudomonas syringae pv. maculicola), they inhibited the crop pathogenic fungi Fusarium avenaceum and Bipolaris sorokiniana with half maximal inhibitory concentrations (IC50) between 31 and 107 µg/mL. Benzyl 2-hydroxy-6-methoxybenzoate, for the first time found in showy goldenrod root, showed the strongest antifungal effect, with IC50 of 25-26 µg/mL for both fungal strains.

Bulbous perennials precisely detect the length of winter and adjust flowering dates.

In order to identify the most relevant environmental parameters that regulate flowering time of bulbous perennials, first flowering dates of 329 taxa over 33 yr are correlated with monthly and daily mean values of 16 environmental parameters (such as insolation, precipitation, temperature, soil water content, etc.) spanning at least 1 yr back from flowering. A machine learning algorithm is deployed to identify the best explanatory parameters because the problem is strongly prone to overfitting for traditional methods: if the number of parameters is the same or greater than the number of observations, then a linear model can perfectly fit the dependent variable (observations). Surprisingly, the best proxy of flowering date fluctuations is the daily snow depth anomaly, which cannot be a signal itself, however it should be related to some integrated temperature signal. Moreover, daily snow depth anomaly as proxy performs much better than mean soil temperature preceding the flowering, the best monthly explanatory parameter. Our findings support the existence of complicated temperature sensing mechanisms operating on different timescales, which is a prerequisite to precisely observe the length and severity of the winter season and translate for example, 'lack of snow' information to meaningful internal signals related to phenophases.

Effects of tree size and park maintenance on soil seed bank of Gleditsia triacanthos, an exotic tree in urban green areas.

The exotic honey locust (Gleditsia triacanthos) is often planted as ornamental tree in urban parks. In Hungary, it occasionally escapes cultivation, in other countries it has already become invasive, and thus, further spread cannot be ruled out. The production of copious long-lived seeds may contribute to its invasiveness. We investigated the soil seed bank of honey locust growing in urban parks of Budapest (Hungary). Soil samples of 1200 cm3 were taken under the canopy of 48 solitary female trees, seeds were extracted by washing, and their viability was assessed by germination test following scarification. For each tree, trunk circumference and level of park maintenance were recorded. Seed bank density varied between 0 and 500 seeds/m2 and in 17 out of 48 cases, it exceeded 100 seeds/m2. Larger trees tended to form better-developed soil seed bank than smaller ones, yet the level of park maintenance has a much stronger effect: trees in neglected parks produced five-times higher density on average than those in perfectly managed parks (126.4 and 24.5 seeds/m2, respectively). For a better understanding of the species' invasion risk, detailed seed ecological studies are needed and to prevent its further spreading, a more careful treatment of its litter is recommended.

Distinction and valorization of 30 root extracts of five goldenrod (Solidago) species.

A high-performance thin-layer chromatography (HPTLC) method was developed for rapid and easy-to-perform discrimination between five goldenrod species present in Europe: the native Solidago virgaurea and the four invasive aliens, S. canadensis, S. gigantea, S. rugosa and S. graminifolia. The chemotaxonomic distinction was based on the chemical profile of their root extracts, confirmed by principal component analysis. This allowed the distinction of the goldenrods in wintertime, when classical morphological methods are not applicable. Their enzyme inhibitory profiles were determined by HPTLC combined with α-glucosidase, ß-glucosidase, α-amylase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) assays. Two compounds of S. canadensis showed the most intense enzyme inhibition in all assays, having also antibacterial activity against Bacillus subtilis, Xanthomonas euvesicatoria and Aliivibrio fischeri strains. HPTLC-high-resolution mass spectrometry (HRMS), bioassay-guided isolation, NMR spectroscopy and literature data led to the characterization and identification of the labdane diterpenes solidagenone and presolidagenone as the active S. canadensis root components. The previously identified polyacetylenes (2Z,8Z and 2E,8Z matricaria esters) of S. virgaurea, also inhibited all enzymes. Except for the known anti-AChE effect of the 2Z,8Z-matricaria ester, this is the first report on the α-glucosidase, ß-glucosidase, α-amylase, AChE and BChE inhibitory activity of these potent compounds. The anti-hyperglycemic effects of the S. canadensis labdanoids were also observed for the first time. Combined with effect-directed assays and HRMS, hyphenated HPTLC allowed an effect-directed high-throughput screening and a fast characterization of multipotent compounds. The investigation of botanicals by fast, hyphenated, bioanalytical tools substantially increased the information gain with regard to active principles (bioprofiling) and efficiently pointed to potent candidates for drug development.

Within-generation and transgenerational plasticity in growth and regeneration of a subordinate annual grass in a rainfall experiment.

Precipitation changes may induce shifts in plant species or life form dominance in ecosystems, making some previously subordinate species abundant. The plasticity of certain plant functional traits of these expanding subordinate species may be one possible mechanism behind their success. In this study, we tested if the subordinate winter annual grass Secale sylvestre shows plasticity in growth and reproduction in response to altered environment associated with field-scale rainfall manipulations (severe drought, moderate drought, and watering) in a semiarid grassland, and whether the maternal environment influences offspring germination or growth in a subsequent pot experiment. Compared to control plots, S. sylvestre plants grew 38% taller, and produced 32% more seeds in severe drought plots, while plants in watered plots were 17% shorter, and had 22% less seeds. Seed mass was greatest in severe drought plots. Plants growing in drought plots had offspring with enhanced juvenile shoot growth compared to the progeny whose mother plants grew in watered plots. These responses are most likely explained by the decreased cover of previously dominant perennial grasses in severe drought plots, which resulted in wetter soil compared to control and watered plots during the peak growth of S. sylvestre. We conclude that the plasticity of this subordinate annual species in response to changing environment may help to gain dominance with recurring droughts that suppress perennial grasses. Our results highlight that exploring both within-generation and transgenerational plasticity of subordinate species may lead to a better prediction of changes in plant species dominance under climate change.

Layer chromatography-bioassays directed screening and identification of antibacterial compounds from Scotch thistle.

The antibacterial profiling of Onopordum acanthium L. leaf extract and subsequent targeted identification of active compounds is demonstrated. Thin-layer chromatography (TLC) and off-line overpressured layer chromatography (OPLC) coupled with direct bioautography were utilized for investigation of the extract against eight bacterial strains including two plant and three human pathogens and a soil, a marine and a probiotic human gut bacteria. Antibacterial fractions obtaining infusion-transfusion OPLC were transferred to HPLC-MS/MS analysis that resulted in the characterization of three active compounds and two of them were identified as, linoleic and linolenic acid. OPLC method was adopted to preparative-scale flash chromatography for the isolation of the third active compound, which was identified after a further semi-preparative HPLC purification as the germacranolide sesquiterpene lactone onopordopicrin. Pure onopordopicrin exhibited antibacterial activity that was specified as minimal inhibitory concentration in the liquid phase as well.

Effect-Directed Discovery of Bioactive Compounds Followed by Highly Targeted Characterization, Isolation and Identification, Exemplarily Shown for Solidago virgaurea.

A nontargeted, effect-directed screening (bioprofiling) and a subsequent highly targeted characterization of antibacterial compounds from plant matrices is demonstrated on the example of Solidago virgaurea root extracts. The procedure comprises high-performance thin-layer chromatography (HPTLC) coupled with six bacterial bioassays including two plant pathogens, a radical scavenging assay, an acetylcholinesterase assay as well as in situ and ex situ mass spectrometric analyses. In situ mass spectra were directly recorded from the adsorbent using the Direct Analysis in Real Time interface (HPTLC-DART-MS), whereas ex situ mass spectra were recorded using an elution head-based interface (HPTLC-ESI-MS). For further bioassay-guided isolation of the main antimicrobial compounds, flash chromatographic fractionation and semipreparative high-performance liquid chromatographic purification were used and nuclear magnetic resonance data allowed the identification of the unknown antimicrobial compounds as 2Z,8Z- and 2E,8Z-matricaria esters. The discovered antibacterial activity was confirmed and specified by a luminometric assay and as minimal inhibitory concentration in the liquid phase.