Out of the three aromatic amino acids, the highest flux in plants is directed towards phenylalanine, which is utilized to synthesize proteins and thousands of phenolic metabolites contributing to plant fitness. Phenylalanine is produced predominantly in plastids via the shikimate pathway and subsequent arogenate pathway, both of which are subject to complex transcriptional and post-transcriptional regulation. Previously, it was shown that allosteric feedback inhibition of arogenate dehydratase (ADT), which catalyzes the final step of the arogenate pathway, restricts flux through phenylalanine biosynthesis. Here, we show that in petunia (Petunia hybrida) flowers, which typically produce high phenylalanine levels, ADT regulation is relaxed, but not eliminated. Moderate expression of a feedback-insensitive ADT increased flux towards phenylalanine, while high overexpression paradoxically reduced phenylalanine formation. This reduction could be partially, but not fully, recovered by bypassing other known metabolic flux control points in the aromatic amino acid network. Using comparative transcriptomics, reverse genetics, and metabolic flux analysis, we discovered that transcriptional regulation of the d-ribulose-5-phosphate 3-epimerase gene in the pentose phosphate pathway controls flux into the shikimate pathway. Taken together, our findings reveal that regulation within and upstream of the shikimate pathway shares control over phenylalanine biosynthesis in the plant cell.
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Eur J Pediatr
December 2024
Division of Child Neurology, Department of Paediatrics, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey.
Unlabelled: Phenylalanine (PA) levels below 360 µmol/L do not require treatment; however, cognitive deficits have been observed in patients with elevated PA levels, necessitating a safe upper limit for treatment and therapeutic objectives. The main purpose of this study is to evaluate the correlation between developmental assessments (Denver Developmental Screening Test-II [DDST-II] and Ankara Developmental Screening Inventory [ADSI]) and electroencephalogram (EEG) findings with blood PA levels and genotypic data in non-phenylketonuria mild Hyperphenylalaninemia (HPA) patients, to re-evaluate their treatment status based on potential adverse outcomes. This study encompassed 40 patients aged 1-5 years diagnosed with HPA and not on treatment, identified through initial blood PA levels, and monitored for a minimum of 1 year on an unrestricted diet.
View Article and Find Full Text PDFSci Total Environ
December 2024
School of Ecology and Environment, Anhui Normal University, Wuhu 241000, China; Anhui Provincial Engineering Laboratory of Water and Soil Pollution Control and Remediation, Anhui Normal University, Wuhu 241000, China; Center of Cooperative Innovation for Recovery and Reconstruction of Degraded Ecosystem in Wanjiang City Belt, Wuhu 241000, China. Electronic address:
As a highly emitted volatile organic compound, toluene significantly contributes to atmospheric pollution and poses high risks to human health. Its anthropogenic source is well understood, while its biosynthesis remains poorly understood, especially by bacterial communities. This research attempted to reveal the temporal changes of bacterial community structure during toluene biosynthesis and identify key bacterial factors using 16S rRNA sequencing gene and machine learning methods.
View Article and Find Full Text PDFJ Sci Food Agric
December 2024
Facultad de Ingeniería Química, Universidad Autónoma de Yucatán, Mérida, Mexico.
Background: α-Amylase (α-AMY) and α-glucosidase (α-GLU) inhibitors are important for controlling postprandial hyperglycemia (PHG). Bixa orellana (annatto) reported inhibitory activity against these enzymes because of its bioactive compound content. However, an understanding of its inhibitory mechanisms and metabolic profile is necessary to establish its therapeutic potential.
View Article and Find Full Text PDFMicrobiome
December 2024
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, People's Republic of China.
Background: Sheep coccidiosis is an infectious parasitic disease that primarily causes diarrhea and growth retardation in young animals, significantly hindering the development of the sheep breeding industry. Cereal grains and animal feeds are frequently contaminated with mycotoxins worldwide, with aflatoxin B1 (AFB1) being the most common form. AFB1 poses a serious threat to gastrointestinal health upon ingestion and affects the function of parenteral organs, thus endangering livestock health.
View Article and Find Full Text PDFJ Plant Physiol
December 2024
Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, 02-776, Warsaw, Poland.
Apple (Malus domestica Borkh.) seeds exhibit deep embryonic dormancy. Uniform germination of isolated apple embryos is observed after 40-day-long cold stratification of the seeds.
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