31 research outputs found
Genomes of multicellular algal sisters to land plants illuminate signaling network evolution
Zygnematophyceae are the algal sisters of land plants. Here we sequenced four genomes of filamentous Zygnematophyceae, including chromosome-scale assemblies for three strains of Zygnema circumcarinatum. We inferred traits in the ancestor of Zygnematophyceae and land plants that might have ushered in the conquest of land by plants: expanded genes for signaling cascades, environmental response, and multicellular growth. Zygnematophyceae and land plants share all the major enzymes for cell wall synthesis and remodifications, and gene gains shaped this toolkit. Co-expression network analyses uncover gene cohorts that unite environmental signaling with multicellular developmental programs. Our data shed light on a molecular chassis that balances environmental response and growth modulation across more than 600 million years of streptophyte evolution
Mechanochemically Enhanced Degradation of Pyrene and Phenanthrene Loaded on Magnetite
The enhancement of the degradation
of polycyclic aromatic hydrocarbons
(PAHs), exemplified by pyrene and phenanthrene, using mild grinding
in the presence of common minerals was investigated. Magnetite, birnessite,
and Na- and Cu-montmorillonite samples were loaded with pyrene or
phenanthrene and ground manually or in a ball mill for short periods
of time. The ground samples were analyzed for PAHs and for their metabolites,
using high-performance liquid chromatography and liquid chromatographyâmass
spectrometry. No degradation of pyrene occurred when it was in contact
with Na-montmorillonite or birnessite. Sorption of pyrene on Cu-montmorillonite
enhanced its degradation, but grinding of the loaded clay actually
inhibited pyreneâs degradation. Phenanthrene hardly degraded
on Cu-montmorillonite. Grinding magnetite loaded with either PAH resulted
in a significant degradation of both (âŒ50% after grinding for
5 min), while in the nonground samples, negligible degradation was
detected. The extent of degradation increased with the duration of
grinding. The degradation of either PAH loaded on magnetite yielded
oxidized products. In soil samples contaminated with PAHs and mixed
with magnetite, a similar grinding-induced degradation pattern was
observed, but with a lower rate. A liquid phase was required to initiate
degradation in the soil. The liquid phase apparently served as the
medium through which the pollutants reached the surface of the degradation-enhancing
mineral
Optimized smallâmolecule pullâdowns define MLBP
Abscisic acid (ABA) receptors belong to the START domain superfamily, which encompasses ligand-binding proteins present in all kingdoms of life. START domain proteins contain a central binding pocket that, depending on the protein, can couple ligand binding to catalytic, transport or signaling functions. In Arabidopsis, the best characterized START domain proteins are the 14 PYR/PYL/RCAR ABA receptors, while the other members of the superfamily do not have assigned ligands. To address this, we used affinity purification of biotinylated proteins expressed transiently in Nicotiana benthamiana coupled to untargeted LC-MS to identify candidate binding ligands. We optimized this method using ABAâPYL interactions and show that ABA co-purifies with wild-type PYL5 but not a binding site mutant. The Kd of PYL5 for ABA is 1.1Â ÎŒm, which suggests that the method has sufficient sensitivity for many ligandâprotein interactions. Using this method, we surveyed a set of 37 START domain-related proteins, which resulted in the identification of ligands that co-purified with MLBP1 (At4G01883) or MLP165 (At1G35260). Metabolite identification and the use of authentic standards revealed that MLBP1 binds to monolinolenin, which we confirmed using recombinant MLBP1. Monolinolenin also co-purified with MLBP1 purified from transgenic Arabidopsis, demonstrating that the interaction occurs in a native context. Thus, deployment of this relatively simple method allowed us to define a proteinâmetabolite interaction and better understand proteinâligand interactions in plants
Modified Compositions of MicelleâClay and LiposomeâClay Composites for Optimal Removal from Water of Bacteria and Hydrophobic Neutral Chemicals
The efficiency in water treatment by granulated complexes formed from the clay bentonite with (i) micelles of the cations of octadecyltrimethyl-ammonium (ODTMA) or (ii) liposomes of didodecyldimethyl-ammonium (DDAB) was investigated. The bentoniteâODTMA complexes were synthesized in three variations: I. mass ratio of 68/32, which resulted in an excess of positive charge of half of the clay cation exchange capacity and is denoted âordinaryâ; II. complexes having higher loads of ODTMA, denoted âenrichedâ; and III. âneutralâ. These variations were designed to optimize the efficiency and reduce the costs of water treatment. âOrdinaryâ and âneutralâ complexes of DDAB were also synthesized. The âordinaryâ complex of ODTMA was shown to be efficient in the removal of anionic/hydrophobic molecules and bacteria. The âenrichedâ complexes were more active in removal of bacteria from water by filtration due to the higher release of free ODTMA cations, which causes biostatic/biocidal effects. The corresponding âordinaryâ and âneutralâ complexes of ODTMA and DDAB yielded the same efficiency in removal from water of the neutral and hydrophobic herbicides, S-metolachlor (i) and alachlor (ii), respectively. Model calculations, which considered sorption/desorption and convection yielded simulations and predictions of filtration results of the herbicides. The neutral complexes are advantageous since their production saves about 1/3 of the amount of ODTMA or DDAB, which constitutes the expensive component in the respective composite
Pesticides and pharmaceuticals data collected during two consecutive years in a Mediterranean micro-estuary
The Alexander micro-estuary, located at the eastern edge of the Mediterranean Sea, is a typical example of small water bodies that suffer from a combination of urban and agricultural pollution, and overuse of its natural water sources. It isâŒ6.5 km long, with maximum depth of 3 m and maximum width of 45 m. To evaluate the anthropogenic stress on the system and its ability to mitigate pollution, water samples were collected within the framework of Ruppin's Estuarine and Coastal Observatory (RECO, see Suari, Y. et al. 2019). Water samples were collected from the estuary head, which drains about 510 km2, and at a point 300 m upstream from the estuary mouth before water flows into the Mediterranean Sea. A total of 236 stormwater and 44 base-flow water samples between December 2016 and December 2018. Stormwater samples were collected every 0.25 â 4 h along the entire course of the flow events using an automated samplers (Sigma 900, Hach Company, Loveland CO, USA; and ISCO 3700 Full-Size Portable Sampler, Teledyne, Lincoln, NE, USA). Base-flow samples were taken once a month using a horizontal grab sampler (5 L, model 110B, OceanTest Equipment, Fort Lauderdale, FL, USA). All samples were filtered using 90mmGF/F filters (nominal pore size of 0.7 ÎŒm, MGF, Sartorius, Göttingen, Germany) and immediately frozen (â20 °C) before chemical analysis. Chemical analysis was performed using liquid chromatography with high-resolution mass spectrometry (LCâHRMS) analysis using a QExactive Plus hybrid FT mass spectrometer coupled with a Dionex Ultimate 3000 RS UPLC (Thermo Fisher Scientific, Waltham, MA, USA). The targeted analysis, which included 15 fungicides, 25 herbicides, 18 Insecticides, and 19 pharmaceuticals, concluded with a total of 21,142 entries. The dataset contains the sampling locations, sampling dates, flood section duration, discharge rate, and the total water volume discharged during the relevant period. The provided data offers an opportunity to explore the sources, transport, and impact of a large mixture of organic pollutants in a confined aquatic system located in an urbanized coastal environment
Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows
<div><p>We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (<i>P</i> < 0.05) in the DEHP-treated group. Estradiol concentration in the follicular fluid was lower in the DEHP-treated group than in controls, and associated with a higher number of follicular pathologies (follicle diameter >25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (<i>P</i> < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (<i>P</i> < 0.04) and 7-day blastocysts (<i>P</i> < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence.</p></div
Developmental competence of bovine oocytes matured in follicular fluid (FF) aspirated from control (FF-control) and DEHP-treated (FF-DEHP) cows.
<p>(A) Proportion of oocytes cleaved to 2- to 4-cell-stage embryos 42â44 h postfertilization, and (B) proportion of embryos developed to the blastocyst stage on day 7 postfertilization, calculated from total oocytes or from cleaved embryos, respectively. Data are presented as means ± SEM; <i>P</i>-value indicates for treatment effect within embryonic stages between experimental groups. (C) Representative images of oocytes that were fertilized and cleaved into 2-cell-stage embryos, 4-cell-stage embryos, and further developed to 7-day blastocysts.</p
DEHP-metabolite concentrations in the plasma before, during and after DEHP exposure.
<p>Cows were administered with water (control) or 100 mg/kg DEHP per day on days 1â3 of the experiment (DEHP-treated). Blood samples were taken before (day 0), during (days 2 and 4) and after (days 11, 19 and 24) DEHP exposure. Samples were analyzed for concentrations of DEHP metabolites mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) and mono[2-(carboxymethyl)hexyl] phthalate (2cx-MMHP) by LCâMS/MS.</p
Phthalate-metabolite concentrations (nM) in pooled plasma, milk and urine samples collected before, during and after DEHP exposure.
<p>*Before exposure = samples collected from all cows on day 0 of the experiment.</p><p>**Control = samples collected from control cows on days 2, 4, 11, 19 and 24 of the experiment.</p><p>***During exposure = samples collected from DEHP-treated cows on days 2 and 4 of the experiment.</p><p>****After exposure = samples collected from DEHP-treated cows on days 11, 19 and 24 of the experiment.</p><p>Data presented as mean ± SEM. Different superscript letters indicate significant difference at <i>P</i> < 0.05 within columns, for each sample and metabolite separately.</p><p>Phthalate-metabolite concentrations (nM) in pooled plasma, milk and urine samples collected before, during and after DEHP exposure.</p