Role of photosynthesis and analysis of key enzymes involved in primary metabolism throughout the lifespan of the tobacco flower

Melatonin, a multifunctional molecule that is present in all living organisms studied, is synthesized in plant cells in several intercellular organelles including in the chloroplasts and in mitochondria. In plants, melatonin has a relevant role as a modulatory agent which improves their tolerance response to biotic and abiotic stress. The role of melatonin in stress conditions on the primary metabolism of plant carbohydrates is reviewed in the present work. Thus, the modulatory actions of melatonin on the various biosynthetic and degradation pathways involving simple carbohydrates (mono- and disaccharides), polymers (starch), and derivatives (polyalcohols) in plants are evaluated. The possible applications of the use of melatonin in crop improvement and postharvest products are examined.

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NTP pattern of avian embryonic red cells: role of RNA degradation and AMP deaminase/5′-nucleotidase activity

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00461.2002 ◽

2003 ◽

Vol 284 (3) ◽

pp. R771-R779 ◽

Cited By ~ 5

Author(s):

Rosemarie Baumann ◽

Robert Götz ◽

Stefanie Dragon

Keyword(s):

Hormonal Regulation ◽

Oxygen Affinity ◽

Erythroid Differentiation ◽

Rna Degradation ◽

Amp Deaminase ◽

Key Enzymes ◽

Allosteric Effectors ◽

Hemoglobin Oxygen Affinity ◽

Adult Hemoglobin

During terminal erythroid differentiation, degradation of RNA is a potential source for nucleotide triphosphates (NTPs) that act as allosteric effectors of hemoglobin. In this investigation, we assessed the developmental profile of RNA and purine/pyrimidine trinucleotides in circulating embryonic chick red blood cells (RBC). Extensive changes of the NTP pattern are observed which differ significantly from what is observed for adult RBC. The biochemical mechanisms have not been identified yet. Therefore, we studied the role of AMP deaminase and IMP/GMP 5′-nucleotidase, which are key enzymes for the regulation of the purine nucleotide pool. Finally, we tested the effect of major NTPs on the oxygen affinity of embryonic/adult hemoglobin. The results are as follows. 1) Together with ATP, UTP and CTP serve as allosteric effectors of hemoglobin. 2) Degradation of erythroid RNA is apparently a major source for NTPs. 3) Developmental changes of nucleotide content depend on the activities of key enzymes (AMP deaminase, IMP/GMP 5′-nucleotidase, and pyrimidine 5′-nucleotidase). 4) Oxygen-dependent hormonal regulation of AMP deaminase adjusts the red cell ATP concentration and therefore the hemoglobin oxygen affinity.

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Gene Transcription in Lactarius quietus-Quercus petraea Ectomycorrhizas from a Forest Soil

Applied and Environmental Microbiology ◽

10.1128/aem.00584-08 ◽

2008 ◽

Vol 74 (21) ◽

pp. 6598-6605 ◽

Cited By ~ 19

Author(s):

P. E. Courty ◽

M. Poletto ◽

F. Duchaussoy ◽

M. Buï¿½e ◽

J. Garbaye ◽

...

Keyword(s):

Gene Expression ◽

Forest Soil ◽

Reverse Transcription ◽

Quercus Petraea ◽

Primary Metabolism ◽

Extraradical Mycelium ◽

Root Tips ◽

Reverse Transcription Pcr ◽

Fungal Genes

ABSTRACT Extracting fungal mRNA from ectomycorrhizas (ECMs) and forest soil samples for monitoring in situ metabolic activities is a significant challenge when studying the role of ECMs in biogeochemical cycles. A robust, simple, rapid, and effective method was developed for extracting RNA from rhizospheric soil and ECMs by adapting previous grinding and lysis methods. The quality and yield of the extracted RNA were sufficient to be used for reverse transcription. RNA extracted from ECMs of Lactarius quietus in a 100-year-old oak stand was used to construct a cDNA library and sequence expressed sequence tags. The transcripts of many genes involved in primary metabolism and in the degradation of organic matter were found. The transcription levels of four targeted fungal genes (glutamine synthase, a general amino acid transporter, a tyrosinase, and N-acetylhexosaminidase) were measured by quantitative reverse transcription-PCR in ECMs and in the ectomycorrhizospheric soil (the soil surrounding the ECMs containing the extraradical mycelium) in forest samples. On average, levels of gene expression for the L. quietus ECM root tips were similar to those for the extraradical mycelium, although gene expression varied up to 10-fold among the samples. This study demonstrates that gene expression from ECMs and soil can be analyzed. These results provide new perspectives for investigating the role of ectomycorrhizal fungi in the functioning of forest ecosystems.

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Glycans and Glycan-Binding Proteins as Regulators and Potential Targets in Leukocyte Recruitment

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.624082 ◽

2021 ◽

Vol 9 ◽

Author(s):

Franziska Krautter ◽

Asif J. Iqbal

Keyword(s):

Binding Proteins ◽

Therapeutic Targets ◽

Leukocyte Recruitment ◽

Regulatory Pathways ◽

Key Enzymes

Leukocyte recruitment is a highly controlled cascade of interactions between proteins expressed by the endothelium and circulating leukocytes. The involvement of glycans and glycan-binding proteins in the leukocyte recruitment cascade has been well-characterised. However, our understanding of these interactions and their regulation has expanded substantially in recent years to include novel lectins and regulatory pathways. In this review, we discuss the role of glycans and glycan-binding proteins, mediating the interactions between endothelium and leukocytes both directly and indirectly. We also highlight recent findings of key enzymes involved in glycosylation which affect leukocyte recruitment. Finally, we investigate the potential of glycans and glycan binding proteins as therapeutic targets to modulate leukocyte recruitment and transmigration in inflammation.

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