Is the redox state of the PQ pool involved in regulating the ET biosynthesis pathway of CAM facultative semi-halophytes?

The mechanisms and factors regulating ethylene (ET) biosynthesis and its action remain largely unexplored, particularly in CAM-facultative and (semi)halophytic plants. The use of Mesembryanthemum crystallinum L. (ice plant) provides a unique opportunity to examine plastoquinone (PQ) - ET interactions in semi-halophytes and CAM-facultative plants simultaneously.

Promoting the remediation of contaminated soils using biochar in combination with bioaugmentation and phytoremediation techniques.

Pollutants in soils are detrimental to ecosystems and agricultural production and may also be a pressing threat to human health. In this context, biochar could be used as part of nature-based solutions to remediate polluted areas. In this work, a series of innovative biochar-based strategies were tested in a soil contaminated by hydrocarbons C > 12 and copper (Cu) to investigate their effectiveness in soil decontamination and revegetation potential.

PFOA accumulation in the leaves of basil (Ocimum basilicum L.) and its effects on plant growth, oxidative status, and photosynthetic performance.

Background: Perfluoroalkyl substances (PFASs) are emerging contaminants of increasing concern due to their presence in the environment, with potential impacts on ecosystems and human health. These substances are considered "forever chemicals" due to their recalcitrance to degradation, and their accumulation in living organisms can lead to varying levels of toxicity based on the compound and species analysed. Furthermore, concerns have been raised about the possible transfer of PFASs to humans through the consumption of edible parts of food plants.

Cultivation of as a source of bioactive compounds in association with soil recovery practices.

Introduction: is a Leguminosae with relevant applications in medicine and soil recovery. This study reports the application of plants in soil recovery and as a source of bioactive compounds.

Methods: Plants were cultivated in semiarid soil under four different fertilizer treatments, urban waste compost at 10 t/ha and 20 t/ha, inorganic fertilizer and a control (no fertilizer).

Insights into the substrate specificity, structure, and dynamics of plant histidinol-phosphate aminotransferase (HISN6).

Histidinol-phosphate aminotransferase is the sixth protein (hence HISN6) in the histidine biosynthetic pathway in plants. HISN6 is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the reversible conversion of imidazole acetol phosphate into L-histidinol phosphate (HOLP). Here, we show that plant HISN6 enzymes are closely related to the orthologs from Chloroflexota.

Arabidopsis thaliana serine hydroxymethyltransferases: functions, structures, and perspectives.

Serine hydroxymethyltransferase (SHM) is one of the hallmarks of one-carbon metabolism. In plants, isoforms of SHM participate in photorespiration and/or transfer the one-carbon unit from L-serine to tetrahydrofolate (THF), hence producing 5,10-CH-THF that is needed, e.g.

Thiamine-dependent regulation of mammalian brain pyridoxal kinase in vitro and in vivo.

Vitamins B (thiamine) and B (pyridox (al/ine/amine)) are crucial for central nervous system (CNS) function and neurogenesis due to the coenzyme action of their phosphorylated derivatives in the brain metabolism of glucose and neurotransmitters. Here, the non-coenzyme action of thiamine on the major mammalian producers of pyridoxal-5'-phosphate (PLP), such as pyridoxal kinase (PdxK) and pyridoxine 5'-phosphate oxidase (PNPO), is characterized. Among the natural thiamine compounds, thiamine triphosphate (ThTP) is the best effector of recombinant human PdxK (hPdxK) in vitro, inhibiting hPdxK in the presence of Mg but activating the Zn -dependent reaction.

Molecular characterization of pyridoxine 5'-phosphate oxidase and its pathogenic forms associated with neonatal epileptic encephalopathy.

Defects of vitamin B metabolism are responsible for severe neurological disorders, such as pyridoxamine 5'-phosphate oxidase deficiency (PNPOD; OMIM: 610090), an autosomal recessive inborn error of metabolism that usually manifests with neonatal-onset severe seizures and subsequent encephalopathy. At present, 27 pathogenic mutations of the gene encoding human PNPO are known, 13 of which are homozygous missense mutations; however, only 3 of them have been characterised with respect to the molecular and functional properties of the variant enzyme forms. Moreover, studies on wild type and variant human PNPOs have so far largely ignored the regulation properties of this enzyme.

Effects of Soil Fertilization on Terpenoids and Other Carbon-Based Secondary Metabolites in Plants: A Comparative Study.

is an evergreen aromatic plant with important commercial interest as it contains numerous essential oils (composed of terpenoid compounds) and phenolic constituents (natural antioxidant compounds). This work aims at evaluating the concomitant effects of different inorganic and organic fertilization treatments and the subsequent increases in soil nutrient availability on terpenoids and other carbon-based secondary metabolites, e.g.

Structural and kinetic properties of serine hydroxymethyltransferase from the halophytic cyanobacterium Aphanothece halophytica provide a rationale for salt tolerance.

Serine hydroxymethyltransferase (SHMT) is a pyridoxal 5'-phosphate-dependent enzyme that plays a pivotal role in cellular one‑carbon metabolism. In plants and cyanobacteria, this enzyme is also involved in photorespiration and confers salt tolerance, as in the case of SHMT from the halophilic cyanobacterium Aphanothece halophytica (AhSHMT). We have characterized the catalytic properties of AhSHMT in different salt and pH conditions.

Structural basis of methotrexate and pemetrexed action on serine hydroxymethyltransferases revealed using plant models.

Serine hydroxymethyltransferases (SHMTs) reversibly transform serine into glycine in a reaction accompanied with conversion of tetrahydrofolate (THF) into 5,10-methylene-THF (5,10-meTHF). In vivo, 5,10-meTHF is the main carrier of one-carbon (1C) units, which are utilized for nucleotide biosynthesis and other processes crucial for every living cell, but hyperactivated in overproliferating cells (e.g.

Allosteric feedback inhibition of pyridoxine 5'-phosphate oxidase from .

In , the synthesis of pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B, takes place through the so-called deoxyxylulose 5-phosphate-dependent pathway, whose last step is pyridoxine 5'-phosphate (PNP) oxidation to PLP, catalyzed by the FMN-dependent enzyme PNP oxidase (PNPOx). This enzyme plays a pivotal role in controlling intracellular homeostasis and bioavailability of PLP. PNPOx has been proposed to undergo product inhibition resulting from PLP binding at the active site.

Biochemical data from the characterization of a new pathogenic mutation of human pyridoxine-5'-phosphate oxidase (PNPO).

PNPO deficiency is responsible of severe neonatal encephalopathy, responsive to pyridoxal-5'-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected new genetic variants on PNPO gene, whose pathogenetic role and clinical expression remain to be established. One of these mutations, Arg116Gln, is of particular interest because of its later onset of symptoms (beyond the first months of life) and its peculiar epileptic manifestations in patients.

A Comprehensive Computational Analysis of Mycobacterium Genomes Pinpoints the Genes Co-occurring with YczE, a Membrane Protein Coding Gene Under the Putative Control of a MocR, and Predicts its Function.

Bacterial proteins belonging to the YczE family are predicted to be membrane proteins of yet unknown function. In many bacterial species, the yczE gene coding for the YczE protein is divergently transcribed with respect to an adjacent transcriptional regulator of the MocR family. According to in silico predictions, proteins named YczR are supposed to regulate the expression of yczE genes.

Pyridoxine-5'-phosphate oxidase (Pnpo) deficiency: Clinical and biochemical alterations associated with the C.347g>A (P.·Arg116gln) mutation.

Background: Pyridoxal-5-phosphate oxidase (PNPO) deficiency presents as a severe neonatal encephalopathy responsive to pyridoxal-5-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected genetic variants on PNPO gene whose pathogenic role and clinical expression remain to be established.

Objective: This paper aims to characterize the functional effects of the c.

Molecular mechanism of PdxR – a transcriptional activator involved in the regulation of vitamin B6 biosynthesis in the probiotic bacterium Bacillus clausii.

Pyridoxal 5'-phosphate (PLP), the well-known active form of vitamin B6 , is an essential enzyme cofactor involved in a large number of metabolic processes. PLP levels need to be finely tuned in response to cell requirements; however, little is known about the regulation of PLP biosynthesis and recycling pathways. The transcriptional regulator PdxR activates transcription of the pdxST genes encoding PLP synthase.

On the mechanism of Escherichia coli pyridoxal kinase inhibition by pyridoxal and pyridoxal 5'-phosphate.

Pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B6, plays a crucial role in several cellular processes. In most organisms, PLP is recycled from nutrients and degraded B6-enzymes in a salvage pathway that involves pyridoxal kinase (PLK), pyridoxine phosphate oxidase and phosphatase activities. Regulation of the salvage pathway is poorly understood.

Isoprene emission aids recovery of photosynthetic performance in transgenic Nicotiana tabacum following high intensity acute UV-B exposure.

Isoprene emission by terrestrial plants is believed to play a role in mitigating the effects of abiotic stress on photosynthesis. Ultraviolet-B light (UV-B) induces damage to the photosynthetic apparatus of plants, but the role of isoprene in UV-B tolerance is poorly understood. To investigate this putative protective role, we exposed non-emitting (NE) control and transgenic isoprene emitting (IE) Nicotiana tabacum (tobacco) plants to high intensity UV-B exposure.

The impact of root temperature on photosynthesis and isoprene emission in three different plant species.

Most of the perennial plant species, particularly trees, emit volatile organic compounds (BVOCs) such as isoprene and monoterpenes, which in several cases have been demonstrated to protect against thermal shock and more generally against oxidative stress. In this paper, we show the response of three strong isoprene emitter species, namely, Phragmites australis, Populus x euramericana, and Salix phylicifolia exposed to artificial or natural warming of the root system in different conditions. This aspect has not been investigated so far while it is well known that warming the air around a plant stimulates considerably isoprene emission, as also shown in this paper.

The impact of winter flooding with saline water on foliar carbon uptake and the volatile fraction of leaves and fruits of lemon (Citrus × limon) trees.

We investigated the consequences of recurrent winter flooding with saline water on a lemon (Citrus×limon (L.) Burm.f.

Increased thermostability of thylakoid membranes in isoprene-emitting leaves probed with three biophysical techniques.

Three biophysical approaches were used to get insight into increased thermostability of thylakoid membranes in isoprene-emittingplants.Arabidopsis (Arabidopsis thaliana) plants genetically modified to make isoprene and Platanus orientalis leaves, in which isoprene emission was chemically inhibited, were used. First, in the circular dichroism spectrum the transition temperature of the main band at 694 nm was higher in the presence of isoprene, indicating that the heat stability of chiral macrodomains of chloroplast membranes, and specifically the stability of ordered arrays of light-harvesting complex II-photosystem II in the stacked region of the thylakoid grana, was improved in the presence of isoprene.

On the induction of volatile organic compound emissions by plants as consequence of wounding or fluctuations of light and temperature.

Among the volatile organic compounds (VOCs) emitted by plants, some are characteristic of stress conditions, but their biosynthesis and the metabolic and environmental control over the emission are still unclear. We performed experiments to clarify whether (1) the emission following wounding can occur at distance from the wounding site, from VOC pools subjected to metabolic signals; and (2) the emission of biogenic VOCs generated by membrane damage (e.g.

Dimethylallyl diphosphate and geranyl diphosphate pools of plant species characterized by different isoprenoid emissions.

Dimethylallyl diphosphate (DMADP) and geranyl diphosphate (GDP) are the last precursors of isoprene and monoterpenes emitted by leaves, respectively. DMADP and GDP pools were measured in leaves of plants emitting isoprene (Populus alba), monoterpenes (Quercus ilex and Mentha piperita), or nonemitting isoprenoids (Prunus persica). Detectable pools were found in all plant species, but P.