scholarly journals Role of Ethylene in the Biosynthetic Pathway of Related-aroma Volatiles Derived from Fatty Acids in Oriental Sweet Melon

2016 ◽  
Vol 141 (4) ◽  
pp. 327-338 ◽  
Author(s):  
Yan Li ◽  
Hongyan Qi ◽  
Yazhong Jin ◽  
Xiaobin Tian ◽  
Linlin Sui ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Biosynthetic Pathway ◽  
Expression Patterns ◽  
Gene Families ◽  
Hydroperoxide Lyase ◽  
Straight Chain ◽  
Alcohol Acetyltransferase ◽  
Key Enzyme ◽  
Aroma Precursors

The catabolism of fatty acid (FA) is regarded as a key pathway of aroma volatile compounds in oriental sweet melon (Cucumis melo var. makuwa). In our research, two cultivars of oriental sweet melon, Caihong7 and Tianbao, were employed to illuminate which step of the biosynthetic pathway of aroma compounds could be regulated by ethylene (ETH). The role of ETH in determining the profiles of straight-chain aroma volatile compounds, levels of FA as aroma precursors, activities of aroma-related enzymes derived from FA pathway, and expression patterns of key enzymes were investigated. Overall, exogenous application of ETH increased the production rates of endogenous ETH and levels of FA. Compared with control, the level of straight-chain esters, especially the acetate, hexanoate, and hexyl esters, was significantly increased by ETH, whereas the content of alcohol and aldehyde reduced. In addition, the metabolism of free FA included linoleic acid (LA), linolenic acid (LeA), and oleic acid (OA) appeared to be ETH-dependent. The activities of lipoxygenase (LOX), alcohol dehydrogenase (ADH), and alcohol acetyltransferase (AAT) as well as the expression patterns of Cm-ADH1, Cm-ADH2, Cm-AAT1, and Cm-AAT4 were positively regulated by ETH. In contrast, hydroperoxide lyase (HPL) and Cm-AAT2 and Cm-AAT3 seemed to be independent of ETH modulation. These results suggested that the dissimilation of FA included LA, LeA, and OA into the acetate, hexanoate, and hexyl esters mainly through ETH regulating the LOX pathway by enhancing the expression of particular members of aroma-related key enzyme gene families as well as the activities of dehydrogenation and esterification.

scholarly journals Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes

2021 ◽  
Author(s):  
Laszlo G Nagy ◽  
Peter Jan Vonk ◽  
Markus Kunzler ◽  
Csenge Foldi ◽  
Mate Viragh ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fruiting Body ◽  
Expression Patterns ◽  
Schizophyllum Commune ◽  
Gene Families ◽  
Second Phase ◽  
Fruiting Bodies ◽  
Body Development ◽  
Fruiting Body Development

Fruiting bodies of mushroom-forming fungi (Agaricomycetes) are among the most complex structures produced by fungi. Unlike vegetative hyphae, fruiting bodies grow determinately and follow a genetically encoded developmental program that orchestrates tissue differentiation, growth and sexual sporulation. In spite of more than a century of research, our understanding of the molecular details of fruiting body morphogenesis is limited and a general synthesis on the genetics of this complex process is lacking. In this paper, we aim to comprehensively identify conserved genes related to fruiting body morphogenesis and distill novel functional hypotheses for functionally poorly characterized genes. As a result of this analysis, we report 921 conserved developmentally expressed gene families, only a few dozens of which have previously been reported in fruiting body development. Based on literature data, conserved expression patterns and functional annotations, we provide informed hypotheses on the potential role of these gene families in fruiting body development, yielding the most complete description of molecular processes in fruiting body morphogenesis to date. We discuss genes related to the initiation of fruiting, differentiation, growth, cell surface and cell wall, defense, transcriptional regulation as well as signal transduction. Based on these data we derive a general model of fruiting body development, which includes an early, proliferative phase that is mostly concerned with laying out the mushroom body plan (via cell division and differentiation), and a second phase of growth via cell expansion as well as meiotic events and sporulation. Altogether, our discussions cover 1480 genes of Coprinopsis cinerea, and their orthologs in Agaricus bisporus, Cyclocybe aegerita, Armillaria ostoyae, Auriculariopsis ampla, Laccaria bicolor, Lentinula edodes, Lentinus tigrinus, Mycena kentingensis, Phanerochaete chrysosporium, Pleurotus ostreatus, and Schizophyllum commune, providing functional hypotheses for ~10% of genes in the genomes of these species. Although experimental evidence for the role of these genes will need to be established in the future, our data provide a roadmap for guiding functional analyses of fruiting related genes in the Agaricomycetes. We anticipate that the gene compendium presented here, combined with developments in functional genomics approaches will contribute to uncovering the genetic bases of one of the most spectacular multicellular developmental processes in fungi. Key words: functional annotation; comparative genomics; cell wall remodeling; development; fruiting body morphogenesis; mushroom; transcriptome

scholarly journals Possible Role of Lipoxygenase in Plant Response to Drought Stress

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 596D-596
Author(s):  
Robert C. Ebel
Keyword(s):  
Drought Stress ◽  
Volatile Compounds ◽  
Hexyl Acetate ◽  
Insect Feeding ◽  
Apple Trees ◽  
Climacteric Fruit ◽  
Apple Leaves ◽  
Key Enzyme ◽  
Pathogenic Infection

Apple leaves were shown to increase 6 volatile compounds in response to drought stress severe enough to promote senescence. Apple trees were allowed to dry to -2.0 MPa and -2.7 MPa, levels that were previously shown to reduce fruit growth by 50% and 70%, respectively. The 6 volatile compounds measured included hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexen-l-ol, hexyl acetate, and (Z)-3-hexenyl acetate. Hexanal, (E)-2-hexenal, and 1-hexanol have been previously shown to be byproducts of lipoxygenase (LOX) activity. There is considerable information in the literature implicating LOX as a key enzyme involved in senescence, whether induced by pathogenic infection, insect feeding, or in ripening climacteric fruit and vegetables. It is reasonable to propose that LOX is also involved in promotion of senescence induced by drought stress.

COX-2: A Molecular Target for Colorectal Cancer Prevention

2005 ◽  
Vol 23 (12) ◽  
pp. 2840-2855 ◽  
Author(s):  
Joanne R. Brown ◽  
Raymond N. DuBois
Keyword(s):  
Biosynthetic Pathway ◽  
Experimental Studies ◽  
Protective Effects ◽  
Randomized Controlled Studies ◽  
Key Enzyme ◽  
Inflammatory Drugs ◽  
Cox 2 ◽  
Colorectal Cancer Prevention ◽  
Cox 2 Inhibitors

Cyclooxygenase (COX), a key enzyme in the prostanoid biosynthetic pathway, has received considerable attention due to its role in human cancers. Observational and randomized controlled studies in many different population cohorts and settings have demonstrated protective effects of nonsteroidal anti-inflammatory drugs (NSAIDs; the inhibitors of COX activity) for colorectal cancers (CRCs). COX-2, the inducible isoform of cyclooxygenase, is overexpressed in early and advanced CRC tissues, which portends a poor prognosis. Experimental studies have thus identified important mechanisms and pathways by which COX-2 plays an important role in carcinogenesis. Selective COX-2 inhibitors have been approved for use as adjunctive therapy for patients with familial polyposis. The role of COX-2 inhibitors is currently being evaluated for use in wider populations.

scholarly journals Amorpha-4,11-diene synthase: a key enzyme in artemisinin biosynthesis and engineering

aBIOTECH ◽  
2021 ◽  
Author(s):  
Jing-Quan Huang ◽  
Xin Fang
Keyword(s):  
Metabolic Engineering ◽  
Synthetic Biology ◽  
Biosynthetic Pathway ◽  
Catalytic Mechanism ◽  
Artemisia Annua ◽  
New Techniques ◽  
Key Enzyme ◽  
Substrate Promiscuity ◽  
Artemisinin Biosynthesis

AbstractAmorpha-4,11-diene synthase (ADS) catalyzes the first committed step in the artemisinin biosynthetic pathway, which is the first catalytic reaction enzymatically and genetically characterized in artemisinin biosynthesis. The advent of ADS in Artemisia annua is considered crucial for the emergence of the specialized artemisinin biosynthetic pathway in the species. Microbial production of amorpha-4,11-diene is a breakthrough in metabolic engineering and synthetic biology. Recently, numerous new techniques have been used in ADS engineering; for example, assessing the substrate promiscuity of ADS to chemoenzymatically produce artemisinin. In this review, we discuss the discovery and catalytic mechanism of ADS, its application in metabolic engineering and synthetic biology, as well as the role of sesquiterpene synthases in the evolutionary origin of artemisinin.

scholarly journals The Azotobacter vinelandii Response Regulator AlgR Is Essential for Cyst Formation

1999 ◽  
Vol 181 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Cinthia Núñez ◽  
Soledad Moreno ◽  
Gloria Soberón-Chávez ◽  
Guadalupe Espín
Keyword(s):  
Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Biosynthetic Pathway ◽  
Azotobacter Vinelandii ◽  
Response Regulator ◽  
Cyst Formation ◽  
Sensor Kinase ◽  
Alginate Production ◽  
Key Enzyme

ABSTRACT Azotobacter vinelandii produces the exopolysaccharide alginate, which is essential for the encystment process. InPseudomonas aeruginosa, as well as in A. vinelandii, the ςE factor encoded byalgU is required for transcription of algD, which encodes a key enzyme of the alginate biosynthetic pathway. TheP. aeruginosa response regulator AlgR activates transcription of algD. fimS, located upstreamalgR, is proposed to encode the AlgR cognate sensor kinase. We have cloned and characterized the A. vinelandii algRgene; the deduced amino acid sequence of the protein encoded by this gene shows 79% identity with its P. aeruginosa homolog. Sequence analysis around the algR gene revealed the absence of a fimS homolog. Inactivation of A. vinelandii algR diminished alginate production by 50%, but did not affectalgD transcription, and completely impaired the capacity to form mature cysts. Electron microscopy of the cyst structures formed by the algR mutant revealed that the encystment process is blocked at the step of exine formation. The transcriptional regulation of the A. vinelandii algR gene and the role of AlgR in alginate production differ significantly from those of its P. aeruginosa counterparts. These differences could be due to the fact that in A. vinelandii, alginate plays a role in encystment, a function not found in P. aeruginosa.

scholarly journals Molecular evolution and expression divergence of three key Met biosynthetic genes in plants: CGS, HMT and MMT

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6023 ◽  
Author(s):  
Man Zhao ◽  
Wenyi Wang ◽  
Lei Wei ◽  
Peng Chen ◽  
Fengjie Yuan ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Expression Patterns ◽  
Evolutionary Relationship ◽  
Evolutionary Model ◽  
Gene Families ◽  
Land Plants ◽  
Seed Plants ◽  
Class 1 ◽  
Food And Feed ◽  
Relationship Of

Methionine (Met) is an essential sulfur-containing amino acid in animals. Cereal and legume crops with limiting levels of Met represent the major food and feed sources for animals. In plants, cystathionine gamma-synthase (CGS), methionine methyltransferase (MMT) and homocysteine methyltransferase (HMT) are committing enzymes synergistically synthesizing Met through the aspartate (Asp) family pathway and the S-methylmethionine (SMM) cycle. The biological functions of CGS, MMT and HMT genes have been respectively studied, whereas their evolution patterns and their contribution to the evolution of Met biosynthetic pathway in plants are unknown. In the present study, to reveal their evolution patterns and contribution, the evolutionary relationship of CGS, MMT and HMT gene families were reconstructed. The results showed that MMTs began in the ancestor of the land plants and kept conserved during evolution, while the CGSs and HMTs had diverged. The CGS genes were divided into two branches in the angiosperms, Class 1 and Class 2, of which Class 2 only contained the grasses. However, the HMT genes diverged into Class 1 and Class 2 in all of the seed plants. Further, the gene structure analysis revealed that the CGSs, MMTs and HMTs were relatively conserved except for the CGSs in Class 2. According to the expression of CGS, HMT and MMT genes in soybeans, as well as in the database of soybean, rice and Arabidopsis, the expression patterns of the MMTs were shown to be consistently higher in leaves than in seeds. However, the expression of CGSs and HMTs had diverged, either expressed higher in leaves or seeds, or showing fluctuated expression. Additionally, the functions of HMT genes had diverged into the repair of S-adenosylmethionine and SMM catabolism during the evolution. The results indicated that the CGS and HMT genes have experienced partial subfunctionalization. Finally, given the evolution and expression of the CGS, HMT and MMT gene families, we built the evolutionary model of the Met biosynthetic pathways in plants. The model proposed that the Asp family pathway existed in all the plant lineages, while the SMM cycle began in the ancestor of land plants and then began to diverge in the ancestor of seed plants. The model suggested that the evolution of Met biosynthetic pathway is basically consistent with that of plants, which might be vital to the growth and development of different botanical lineages during evolution.

Tryptophan-Niacin Metabolism in Rat with Puromycin Aminonucleoside-Induced Nephrosis

2006 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Yukari Egashira ◽  
Shin Nagaki ◽  
Hiroo Sanada
Keyword(s):  
Body Weight ◽  
Urinary Excretion ◽  
Enzyme Activities ◽  
Treated Group ◽  
Control Group ◽  
Puromycin Aminonucleoside ◽  
Low Level ◽  
Key Enzyme

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.

Dysregulation of HOX as a Potential Therapeutic Target in Breast Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim
Keyword(s):  
Breast Cancer ◽  
Hox Genes ◽  
Therapeutic Potential ◽  
Expression Patterns ◽  
Genome Structure ◽  
Control Cell ◽  
Three Dimensional ◽  
Cellular Processes ◽  
Hox Protein

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.

Acid ceramidase, a double-edged sword in cancer aggression: A minireview

2020 ◽  
Vol 20 ◽  
Author(s):  
Helen Shiphrah Vethakanraj ◽  
Niveditha Chandrasekaran ◽  
Ashok Kumar Sekar
Keyword(s):  
Cell Fate ◽  
Cancer Progression ◽  
Potential Role ◽  
Tumour Progression ◽  
Acid Ceramidase ◽  
The Core ◽  
The Past ◽  
Sphingosine 1 Phosphate ◽  
Key Enzyme

: Acid ceramidase (AC), the key enzyme of the ceramide metabolic pathway hydrolyzes pro-apoptotic ceramide to sphingosine, which by the action of sphingosine-1-kinase is metabolized to mitogenic sphingosine-1-phosphate. The intracellular level of AC determines ceramide/sphingosine-1-phosphate rheostat which in turn decides the cell fate. The upregulated AC expression during cancerous condition acts as a “double-edged sword” by converting pro-apoptotic ceramide to anti-apoptotic sphingosine-1-phosphate, wherein on one end, the level of ceramide is decreased and on the other end, the level of sphingosine-1-phosphate is increased, thus altogether aggravating the cancer progression. In addition, cancer cells with upregulated AC expression exhibited increased cell proliferation, metastasis, chemoresistance, radioresistance and numerous strategies were developed in the past to effectively target the enzyme. Gene silencing and pharmacological inhibition of AC sensitized the resistant cells to chemo/radiotherapy thereby promoting cell death. The core objective of this review is to explore AC mediated tumour progression and the potential role of AC inhibitors in various cancer cell lines/models.

scholarly journals Impact of Environmental Factors on Stilbene Biosynthesis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Alessio Valletta ◽  
Lorenzo Maria Iozia ◽  
Francesca Leonelli
Keyword(s):  
Environmental Factors ◽  
Biosynthetic Pathway ◽  
In Planta ◽  
Organ Cultures ◽  
Related Plant ◽  
Valuable Compounds ◽  
Stilbene Compounds ◽  
Stilbene Biosynthesis ◽  
Abiotic Environmental Factors

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds.

Sign in / Sign up

Export Citation Format

Share Document