Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis

Plants are sessile and therefore have developed mechanisms to adapt to their environment, including the soil mineral nutrient composition. Ionomics is a developing functional genomic strategy designed to rapidly identify the genes and gene networks involved in regulating how plants acquire and accumulate these mineral nutrients from the soil. Here, we report on the coupling of high-throughput elemental profiling of shoot tissue from various Arabidopsis accessions with DNA microarray-based bulk segregant analysis and reverse genetics, for the rapid identification of genes from wild populations of Arabidopsis that are involved in regulating how plants acquire and accumulate Na(+) from the soil. Elemental profiling of shoot tissue from 12 different Arabidopsis accessions revealed that two coastal populations of Arabidopsis collected from Tossa del Mar, Spain, and Tsu, Japan (Ts-1 and Tsu-1, respectively), accumulate higher shoot levels of Na(+) than do Col-0 and other accessions. We identify AtHKT1, known to encode a Na(+) transporter, as being the causal locus driving elevated shoot Na(+) in both Ts-1 and Tsu-1. Furthermore, we establish that a deletion in a tandem repeat sequence approximately 5 kb upstream of AtHKT1 is responsible for the reduced root expression of AtHKT1 observed in these accessions. Reciprocal grafting experiments establish that this loss of AtHKT1 expression in roots is responsible for elevated shoot Na(+). Interestingly, and in contrast to the hkt1-1 null mutant, under NaCl stress conditions, this novel AtHKT1 allele not only does not confer NaCl sensitivity but also cosegregates with elevated NaCl tolerance. We also present all our elemental profiling data in a new open access ionomics database, the Purdue Ionomics Information Management System (PiiMS; http://www.purdue.edu/dp/ionomics). Using DNA microarray-based genotyping has allowed us to rapidly identify AtHKT1 as the casual locus driving the natural variation in shoot Na(+) accumulation we observed in Ts-1 and Tsu-1. Such an approach overcomes the limitations imposed by a lack of established genetic markers in most Arabidopsis accessions and opens up a vast and tractable source of natural variation for the identification of gene function not only in ionomics but also in many other biological processes.     

Development of selective and reversible pyrazoline based MAO-A inhibitors: Synthesis,biological evaluation and docking studies

3,5-Diaryl pyrazolines analogs were synthesized and evaluated for their monoamine oxidase (MAO) inhibitory activity. The compounds were found reversible and selective towards MAO-A with selectivity index in the magnitude of 10³–10⁵. The docking studies were carried out to gain further structural insights of the binding mode and possible interactions with the active site of MAO-A. Interestingly, the theoretical (K_i) values obtained by molecular docking studies were in congruence with their experimental (K_i) values.     

Arbuscular mycorrhizal morphology and dark septate fungal associations in medicinal and aromatic plants of Western Ghats, Southern India

We investigated roots of 107 medicinal and aromatic plants (MAPs) in the Western Ghats region of Southern India for arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) associations. Of the 107 MAPs belonging to 98 genera in 52 families examined, 79 were AM and 38 harbored a DSE association. Typical Arum- and Paris-type mycorrhizas are first reported in the presumed nonmycorrhizal family Amaranthaceae. Similarly, DSE associations are recorded for the first time in nine plant families and 37 plant species. Thirty MAPs had both AM and DSE associations. The number of MAPs having Arum-type mycorrhiza was greater than those having Paris-type. This was more prominent among herbaceous plants than in trees where the Paris-type was predominant. Similarly, the Arum-type was more prevalent in annuals than in perennials. DSE associations were more frequent in herbs and perennials compared to other MAPs.     

Optimization of Antimicrobial Production by a Marine Actinomycete Streptomyces afghaniensis VPTS3-1 Isolated from Palk Strait, East Coast of India

Totally 25 marine soil samples were collected from the region of Palk Strait of Bay of Bengal, Tamil Nadu, and were subjected to the isolation of actinomycetes. Sixty-eight morphologically distinct isolates were obtained and 37% (25) of them had antimicrobial activity. The potential producer was named as Streptomyces sp. VPTS3-1 and the phylogenetic evaluation on the basis of 16S rDNA sequence further categorized the organism as Streptomyces afghaniensis VPTS3-1. Further, the antimicrobial compound was extracted from the isolate using various solvents and the antimicrobial efficacies were tested against bacterial and fungal pathogens. In addition, in vitro optimization of parameters for the antimicrobial compound production revealed that the suitable pH as 7–8, the period of incubation as 9 days, temperature (30°C), salinity (2%), and starch and KNO₃ as the suitable carbon and nitrogen sources respectively in starch–casein medium.     

An overview of enzymatic production of biodiesel

Biodiesel production has received considerable attention in the recent past as a biodegradable and nonpolluting fuel. The production of biodiesel by transesterification process employing alkali catalyst has been industrially accepted for its high conversion and reaction rates. Recently, enzymatic transesterification has attracted much attention for biodiesel production as it produces high purity product and enables easy separation from the byproduct, glycerol. But the cost of enzyme remains a barrier for its industrial implementation. In order to increase the cost effectiveness of the process, the enzyme (both intracellular and extracellular) is reused by immobilizing in a suitable biomass support particle and that has resulted in considerable increase in efficiency. But the activity of immobilized enzyme is inhibited by methanol and glycerol which are present in the reacting mixture. The use of tert-butanol as solvent, continuous removal of glycerol, stepwise addition of methanol are found to reduce the inhibitory effects thereby increasing the cost effectiveness of the process. The present review analyzes these methods reported in literature and also suggests a suitable method for commercialization of the enzymatic process.     

Fragments of obestatin as modulators of feed intake, circulating lipids, and stored fat

Obestatin, shown to reduce feed intake and gain in body weight in rodents, is a very attractive candidate to be used against obesity. In this study, we aimed to investigate the relationship between the primary structure and activity of obestatin. Also of interest to us is a peptide of minimal length that closely mimics obestatin. Towards the same, we synthesized rodent obestatin and three overlapping fragments spanning residues 1-13, 6-18, and 11-23 of obestatin. These peptides subsequent to purification and characterization were tested upon adult male mice for their ability to reduce feed intake and gain in body weight. The N-terminal peptide (residues 1-13) mimicked obestatin the closest. The middle fragment (residues 6-18) significantly reduced epididymal fat without much altering feed intake or body weight.     

Role of glutathione on renal mitochondrial status in hyperoxaluria

Role of glutathione on kidney mitochondrial integrity and function during stone forming process in hyperoxaluric state was investigated in male albino rats of Wistar strain. Hyperoxaluria was induced by feeding ethylene glycol (EG) in drinking water. Glutathione was depleted by administering buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis. Glutathione monoester (GME) was administered for supplementing glutathione. BSO treatment alone or along with EG, depleted mitochondrial GSH by 40% and 51% respectively. Concomitantly, there was remarkable elevation in lipid peroxidation and oxidation of protein thiols. Mitochondrial oxalate binding was enhanced by 74% and 129% in BSO and BSO + EG treatment. Comparatively, EG treatment produced only a 33% increase in mitochondrial oxalate binding. Significant alteration in calcium homeostasis was seen following BSO and BSO + EG treatment. This may be due to altered mitochondrial integrity and function as evidenced from decreased activities of mitochondrial inner membrane marker enzymes, succinate dehydrogenase and cytochrome-c-oxidase and respiratory control ratio and enhanced NADH oxidation by mitochondria in these two groups. NADH oxidation (r = -0.74) and oxalate deposition in the kidney (r = -0.70) correlated negatively with mitochondrial glutathione depletion. GME supplementation restored normal level of GSH and maintained mitochondrial integrity and function, as a result of which oxalate deposition was prevented despite hyperoxaluria. These results suggest that mitochondrial dysfunction resulting from GSH depletion could be a contributing factor in the development of calcium oxalate stones.     

Evaluating the frequency of English language requirements in clinical trial eligibility criteria: A systematic analysis using ClinicalTrials.gov

BackgroundA number of prior studies have demonstrated that research participants with limited English proficiency in the United States are routinely excluded from clinical trial participation. Systematic exclusion through study eligibility criteria that require trial participants to be able to speak, read, and/or understand English affects access to clinical trials and scientific generalizability. We sought to establish the frequency with which English language proficiency is required and, conversely, when non-English languages are affirmatively accommodated in US interventional clinical trials for adult populations.Methods and findingsWe used the advanced search function on ClinicalTrials.gov specifying interventional studies for adults with at least 1 site in the US. In addition, we used these search criteria to find studies with an available posted protocol. A computer program was written to search for evidence of English or Spanish language requirements, or the posted protocol, when available, was manually read for these language requirements. Of the 14,367 clinical trials registered on ClinicalTrials.gov between 1 January 2019 and 1 December 2020 that met baseline search criteria, 18.98% (95% CI 18.34%–19.62%; n = 2,727) required the ability to read, speak, and/or understand English, and 2.71% (95% CI 2.45%–2.98%; n = 390) specifically mentioned accommodation of translation to another language. The remaining trials in this analysis and the following sub-analyses did not mention English language requirements or accommodation of languages other than English. Of 2,585 federally funded clinical trials, 28.86% (95% CI 27.11%–30.61%; n = 746) required English language proficiency and 4.68% (95% CI 3.87%–5.50%; n = 121) specified accommodation of other languages; of the 5,286 industry-funded trials, 5.30% (95% CI 4.69%–5.90%; n = 280) required English and 0.49% (95% CI 0.30%–0.69%; n = 26) accommodated other languages. Trials related to infectious disease were less likely to specify an English requirement than all registered trials (10.07% versus 18.98%; relative risk [RR] = 0.53; 95% CI 0.44–0.64; p < 0.001). Trials related to COVID-19 were also less likely to specify an English requirement than all registered trials (8.18% versus 18.98%; RR = 0.43; 95% CI 0.33–0.56; p < 0.001). Trials with a posted protocol (n = 366) were more likely than all registered clinical trials to specify an English requirement (36.89% versus 18.98%; RR = 1.94, 95% CI 1.69–2.23; p < 0.001). A separate analysis of studies with posted protocols in 4 therapeutic areas (depression, diabetes, breast cancer, and prostate cancer) demonstrated that clinical trials related to depression were the most likely to require English (52.24%; 95% CI 40.28%–64.20%). One limitation of this study is that the computer program only searched for the terms “English” and “Spanish” and may have missed evidence of other language accommodations. Another limitation is that we did not differentiate between requirements to read English, speak English, understand English, and be a native English speaker; we grouped these requirements together in the category of English language requirements.ConclusionsA meaningful percentage of US interventional clinical trials for adults exclude individuals who cannot read, speak, and/or understand English, or are not native English speakers. To advance more inclusive and generalizable research, funders, sponsors, institutions, investigators, institutional review boards, and others should prioritize translating study materials and eliminate language requirements unless justified either scientifically or ethically.

Akila Muthukumar and coauthors, systematically analyze ClinicalTrials.gov to evaluate the frequency of English language requirements in clinical trial eligibility criteria.     

Glutathione peroxidase3 of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> protects phospholipids during cadmium-induced oxidative stress

The present study was undertaken to determine the role of glutathione peroxidase3 (gpx3) in phospholipid protection in cells. Wild-type (WT) cells showed an overall increase in phospholipids upon 50 μM cadmium (Cd)-treatment, whereas an untreated gpx3Δ strain showed a drastic reduction in overall phospholipids which was further reduced with 50 μM Cd. In WT cells, Cd-exposure increased the short chain fatty acids and decreased the unsaturated fatty acids and the magnitude was high in Cd-treated gpx3Δ cells. Purified recombinant gpx3p showed higher activity with phospholipid hydroperoxides than shorter hydroperoxides. An increase in gpx activity was observed in Cd-treated WT cells and no such alteration was observed in gpx3Δ. WT cells treated with Cd showed an increase in MDA over untreated, while untreated gpx3Δ cells themselves showed a higher level of MDA which was further enhanced with Cd-treatment. Iron, zinc and calcium levels were significantly altered in WT and gpx3Δ cells during Cd-treatment.