Dispersive interactions in the adsorption and corrosion inhibition effects of Alstonia boonei on mild steel in acidic environments

Purpose The purpose of this paper is to study the adsorption properties of a proven traditional medicine of West Africa origin, Alstonia boonei with an attempt to evaluate its application in the corrosion protection of mild steel in 5 M H2SO4 and 5 M HCl. Design/methodology/approach Phytochemical screening and Fourier transform infrared spectroscopy analysis were used to characterize the methanolic extract of the plant. Gravimetry, gasometry and electrochemical techniques were used in the corrosion inhibition studies of the extract and computational studies were used to describe the electronic and adsorption properties of eugenol, the most abundant phytochemical in Alstonia boonei. Findings The extract acted as a mixed-type inhibitor in both acidic solutions, with improved inhibition efficiency achieved with increasing concentration. While the efficiency increased with temperature for the HCl system, it decreased for the H2SO4 system. The mechanism of adsorption proposed for Alstonia boonei was chemisorption in the HCl system and physisorption in the H2SO4 system, and the adsorptions obeyed Langmuir isotherm at low temperatures. Computational parameters showed that eugenol, being a representative of Alstonia boonei, possesses excellent adsorption properties and has the potential to compete with other established plant-based corrosion inhibitors. Research limitations/implications As opposed to pure compounds with distinctive corrosion effects, plant extracts are generally composed of a myriad of phytoconstituents that competitively promote or inhibit the corrosion process and their net effect is evident as inhibition efficiencies. This is, therefore, the main research limitation associated with the corrosion inhibition study of Alstonia boonei. Originality/value Being very rich in antioxidant properties by its proven curative and preventive effects for diseases, the interest was stimulated towards the attractive results that abound from its corrosion protection of metals via its anti-oxidation route.

Fungal Keratitis Due to Fusarium lichenicola: A Case Report and Global Review of Fusarium lichenicola Keratitis

Fusarium species are among the most commonly isolated causes of fungal keratitis. Most species of the genus Fusarium belong to Fusarium solani species complex (FSSC). Fusarium lichenicola, a member of the FSSC complex, is a well-established plant and human pathogen. However, reports of fungal keratitis due to Fusarium lichenicola have not been frequently reported. To the best of our knowledge, only twelve cases of Fusarium lichenicola keratitis have been reported in the past fifty years. Clinical cases of Fusarium lichenicola may have most likely been misidentified because of the lack of clinical and microbiological suspicion, as well as inadequate diagnostic facilities in many tropical countries where the burden of the disease may be the highest. We report a case of fungal keratitis caused by Fusarium lichenicola and present a global review of the literature of all cases of fungal keratitis caused by this potentially blinding fungus.

Transcriptome Signatures in Pseudomonas simiae WCS417 Shed Light on Role of Root-Secreted Coumarins in Arabidopsis-Mutualist Communication

Pseudomonas simiae WCS417 is a root-colonizing bacterium with well-established plant-beneficial effects. Upon colonization of Arabidopsis roots, WCS417 evades local root immune responses while triggering an induced systemic resistance (ISR) in the leaves. The early onset of ISR in roots shows similarities with the iron deficiency response, as both responses are associated with the production and secretion of coumarins. Coumarins can mobilize iron from the soil environment and have a selective antimicrobial activity that impacts microbiome assembly in the rhizosphere. Being highly coumarin-tolerant, WCS417 induces the secretion of these phenolic compounds, likely to improve its own niche establishment, while providing growth and immunity benefits for the host in return. To investigate the possible signaling function of coumarins in the mutualistic Arabidopsis-WCS417 interaction, we analyzed the transcriptome of WCS417 growing in root exudates of coumarin-producing Arabidopsis Col-0 and the coumarin-biosynthesis mutant f6′h1. We found that coumarins in F6′H1-dependent root exudates significantly affected the expression of 439 bacterial genes (8% of the bacterial genome). Of those, genes with functions related to transport and metabolism of carbohydrates, amino acids, and nucleotides were induced, whereas genes with functions related to cell motility, the bacterial mobilome, and energy production and conversion were repressed. Strikingly, most genes related to flagellar biosynthesis were down-regulated by F6′H1-dependent root exudates and we found that application of selected coumarins reduces bacterial motility. These findings suggest that coumarins’ function in the rhizosphere as semiochemicals in the communication between the roots and WCS417. Collectively, our results provide important novel leads for future functional analysis of molecular processes in the establishment of plant-mutualist interactions.

Agricultural populations of Festuca pratensis (Poaceae) on the coal mining spoils in the forest-steppe of the Kuznetsk Basin, Russia

The study of meadow fescue agropopulations was conducted in the agricultural phytocoenoses, established on the leveled coal mining spoils in the forest-steppe zone of the Kuznetsk Basin mining region in Russia. In agrophytocoenoses the fescue is not a dominant species, as in the natural meadows of herbs and fescue, which occupied the area prior to spoiling. However, the presence of the meadow fescue in the newly established plant communities resulted in increasing their biological diversity and improving the forage quality. The species was shown to sustain in agricultural communities on the coal mining spoils for more than 25 years, whereas when sown on the zonal soils it maintains it presence for 4-6 years. The ontogenetic groups of the plant in all communities were found to be dominated by virginile, young and mid-aged generative specimen. By the 25th year of agricultural phytocoenoses development the vitality of the agropopulations decreased on the coal mining spoils, composed of both Quaternary and Permian sediments. The study showed for the first time that meadow fescue is a species with good potential to restore vegetation cover in the areas disturbed by the open coal mining.

Plant DNA barcoding necessitates marker-specific efforts to establish more comprehensive reference databases

The problem of low species-level identification rates in plants by DNA barcoding is exacerbated by the fact that reference databases are far from being comprehensive. We investigate the impact of increased sampling depth on identification success by analyzing the efficacy of established plant barcode marker sequences (rbcL, matK, trnL-trnF, psbA-trnH, ITS). Adding sequences of the same species to the reference database led to an increase in correct species assignment of +10.9% for rbcL and +19.0% for ITS. Simultaneously, erroneous identification dropped from ∼40% to ∼12.5%. Despite its evolutionary constraints, ITS showed the highest identification rate and identification gain by increased sampling effort, which makes it a very suitable marker in the planning phase of a barcode study. The limited sequence availability of trnL-trnF is problematic for an otherwise very promising plastid plant barcoding marker. Future developments in machine learning algorithms have the potential to give new impetus to plant barcoding, but are dependent on extensive reference databases. We expect that our results will be incorporated into future plans for the development of DNA barcoding reference databases and will lead to these being developed with greater depth and taxonomic coverage.

A comprehensive toolkit for quick and easy visualization of marker proteins, protein-protein interactions and cell morphology in Marchantia polymorpha

Even though stable genomic transformation of sporelings and thalli of Marchantia polymorpha is comparatively straightforward and efficient, numerous problems can arise during critical phases of the process such as efficient spore production, poor selection capacity of antibiotics or low transformation efficiency. It is therefore also desirable to establish quick methods not relying on stable transgenics to analyze the localization, interactions and functions of proteins of interest. The introduction of foreign DNA into living cells via biolistic mechanisms has been first reported roughly 30 years ago and has been commonly exploited in established plant model species such as Arabidopsis thaliana or Nicotiana benthamiana. Here we report the fast and reliable transient biolistic transformation of Marchantia thallus epidermal cells using fluorescent protein fusions. We present a catalogue of fluorescent markers which can be readily used for tagging of a variety of subcellular compartments. Moreover, we report the functionality of the bimolecular fluorescence complementation (BiFC) in M. polymorpha with the example of the p-body markers MpDCP1/2. Finally, we provide standard staining procedures for live cell imaging in M. polymorpha, applicable to visualize cell boundaries or cellular structures, to complement or support protein localizations and to understand how results gained by transient transformations can be embedded in cell architecture and dynamics. Taken together, we offer a set of easy and quick tools for experiments that aim at understanding subcellular localization, protein-protein interactions and thus functions of proteins of interest in the emerging early diverging land plant model M. polymorpha.

Evolution in novel environments: do restored prairie populations experience strong selection?

When populations colonize new habitats, they are likely to experience novel environmental conditions, and as a consequence may experience strong selection. While selection and the resulting evolutionary responses may have important implications for establishment success in colonizing populations, few studies have estimated selection in such scenarios. Here we examined evidence of selection in recently established plant populations in two prairie restorations in close proximity (< 15 km apart) using two approaches: 1) we tested for evidence of past selection on a suite of traits in two Chamaecrista fasciculata populations by comparing the restored populations to each other and their shared source population in common gardens to quantify evolutionary responses and 2) we measured selection in the field. We found evidence of past selection on flowering time, specific leaf area, and root nodule production in one of the populations, but detected contemporary selection on only one trait (plant height). This demonstrates that while selection can occur in colonizing populations, resulting in significant evolutionary responses in less than 6 generations, rapid evolutionary responses may be weak in even nearby populations sown with the same source population. Because contemporary measures of selection rarely predicted observed evolutionary responses, it also suggests that selection likely differs over the early stages of succession that characterize young prairies.

Plant-Based Diets and Hypertension

Hypertension is a global epidemic and a risk factor for many adverse outcomes, including cardiovascular disease, kidney disease, and death. Lifestyle plays a significant role in the development and maintenance of hypertension, and guidelines from several organizations recommend lifestyle modifications as first-line intervention for hypertensive patients. Data supporting the use of plant-based diets in the treatment of hypertension goes back almost a century. More recently, clinical trial data, including randomized controlled trials, have established plant-based diets as an effective lifestyle intervention for high blood pressure (BP). Plant-based diets differ from the standard American diet in a myriad of ways, with some substances being present in either substantially higher or lower amounts. Although the precise mechanism of a plant-based diet’s beneficial effects on BP is unknown, many of these differences may be responsible. Attributes of a plant-based diet that may lower BP include a lower energy content leading to weight loss, a lower sodium content, an increased potassium content, reduced oxidative stress, higher bioavailability of the vasodilator nitric oxide, and beneficial effects on the microbiome. The evidenced-based benefits of plant-based diets in treating hypertension should lead providers to advocate for this dietary pattern for their patients.