Polyphenol oxidase and enzymatic browning in apricot (Prunus armeniaca L.): Effect on phenolic composition and deduction of main substrates.
Ontology highlight
ABSTRACT:
SUBMITTER: Derardja AE
PROVIDER: S-EPMC8789516 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Polyphenol oxidase from apricot (Prunus armeniaca) (PaPPO) was purified in its latent form (L-PaPPO), and the molecular weight was determined to be 63 kDa by SDS-PAGE. L-PaPPO was activated in the presence of substrate at low pH. The activity was enhanced by CuSO4 and low concentrations (≤ 2 mM) of SDS. PaPPO has its pH and temperature optimum at pH 4.5 and 45 °C for catechol as substrate. It showed diphenolase activity and highest affinity toward 4-methylcatechol (KM = 2.0 mM) and chlorogenic acid (KM = 2.7 mM). L-PaPPO was found to be spontaneously activated during storage at 4 °C, creating a new band at 38 kDa representing the activated form (A-PaPPO). The mass of A-PaPPO was determined by mass spectrometry as 37 455.6 Da (Asp102 → Leu429). Both L-PaPPO and A-PaPPO were identified as polyphenol oxidase corresponding to the known PaPPO sequence (UniProt O81103 ) by means of peptide mass fingerprinting.
| S-EPMC5609118 | biostudies-literature
Project description:There is an increasing interest in polyphenols, plant secondary metabolites, in terms of fruit quality and diet, mainly due to their antioxidant effect. However, the identification of key gene enzymes and their roles in the phenylpropanoid pathway in temperate fruits species remains uncertain. Apricot (Prunus armeniaca) is a Mediterranean fruit with high diversity and fruit quality properties, being an excellent source of polyphenol compounds. For a better understanding of the phenolic pathway in these fruits, we selected a set of accessions with genetic-based differences in phenolic compounds accumulation. HPLC analysis of the main phenolic compounds and transcriptional analysis of the genes involved in key steps of the polyphenol network were carried out. Phenylalanine ammonia-lyase (PAL), dihydroflavonol-4-reductase (DFR) and flavonol synthase (FLS) were the key enzymes selected. Orthologous of the genes involved in transcription of these enzymes were identified in apricot: ParPAL1, ParPAL2, ParDFR, ParFLS1 and ParFLS2. Transcriptional data of the genes involved in those critical points and their relationships with the polyphenol compounds were analyzed. Higher expression of ParDFR and ParPAL2 has been associated with red-blushed accessions. Differences in expression between paralogues could be related to the presence of a BOXCOREDCPAL cis-acting element related to the genes involved in anthocyanin synthesis ParFLS2, ParDFR and ParPAL2.
| S-EPMC8037730 | biostudies-literature
Project description:Under normal environmental conditions, many plants synthesize cyanogenic glycosides, which are able to release hydrogen cyanide upon hydrolysis. Each year, there are frequent livestock and occasional human victims of cyanogenic plants consumption. The present work aims to determine the hydrocyanic acid content in different samples of cyanogenic plants, selected from the Tunisian flora, and in the almond syrup. In order to evaluate their toxicity and their impact on the consumer health in the short term as well as in the long term, using the ISO 2164-1975 NT standard, relating to the determination of cyanogenic heterosides in leguminous plants.
| S-EPMC3793392 | biostudies-literature
Project description:Apricots, scientifically known as Prunus armeniaca L, are drupes that resemble and are closely related to peaches or plums. As one of the top consumed fruits, apricots are widely grown worldwide except in Antarctica. A high-quality reference genome for apricot is still unavailable, which has become a handicap that has dramatically limited the elucidation of the associations of phenotypes with the genetic background, evolutionary diversity, and population diversity in apricot. DNA from P. armeniaca was used to generate a standard, size-selected library with an average DNA fragment size of ~20?kb. The library was run on Sequel SMRT Cells, generating a total of 16.54?Gb of PacBio subreads (N50?=?13.55?kb). The high-quality P. armeniaca reference genome presented here was assembled using long-read single-molecule sequencing at approximately 70× coverage and 171× Illumina reads (40.46?Gb), combined with a genetic map for chromosome scaffolding. The assembled genome size was 221.9?Mb, with a contig NG50 size of 1.02?Mb. Scaffolds covering 92.88% of the assembled genome were anchored on eight chromosomes. Benchmarking Universal Single-Copy Orthologs analysis showed 98.0% complete genes. We predicted 30,436 protein-coding genes, and 38.28% of the genome was predicted to be repetitive. We found 981 contracted gene families, 1324 expanded gene families and 2300 apricot-specific genes. The differentially expressed gene (DEG) analysis indicated that a change in the expression of the 9-cis-epoxycarotenoid dioxygenase (NCED) gene but not lycopene beta-cyclase (LcyB) gene results in a low ?-carotenoid content in the white cultivar "Dabaixing". This complete and highly contiguous P. armeniaca reference genome will be of help for future studies of resistance to plum pox virus (PPV) and the identification and characterization of important agronomic genes and breeding strategies in apricot.
| S-EPMC6861294 | biostudies-literature
Project description:RNA-Seq has proven to be a very powerful tool in the analysis of the Plum pox virus (PPV, sharka disease)/Prunus interaction. This technique is an important complementary tool to other means of studying genomics. In this work an analysis of gene expression of resistance/susceptibility to PPV in apricot is performed. RNA-Seq has been applied to analyse the gene expression changes induced by PPV infection in leaves from two full-sib apricot genotypes, "Rojo Pasión" and "Z506-7", resistant and susceptible to PPV, respectively. Transcriptomic analyses revealed the existence of more than 2,000 genes related to the pathogen response and resistance to PPV in apricot. These results showed that the response to infection by the virus in the susceptible genotype is associated with an induction of genes involved in pathogen resistance such as the allene oxide synthase, S-adenosylmethionine synthetase 2 and the major MLP-like protein 423. Over-expression of the Dicer protein 2a may indicate the suppression of a gene silencing mechanism of the plant by PPV HCPro and P1 PPV proteins. On the other hand, there were 164 genes involved in resistance mechanisms that have been identified in apricot, 49 of which are located in the PPVres region (scaffold 1 positions from 8,050,804 to 8,244,925), which is responsible for PPV resistance in apricot. Among these genes in apricot there are several MATH domain-containing genes, although other genes inside (Pleiotropic drug resistance 9 gene) or outside (CAP, Cysteine-rich secretory proteins, Antigen 5 and Pathogenesis-related 1 protein; and LEA, Late embryogenesis abundant protein) PPVres region could also be involved in the resistance.
| S-EPMC4684361 | biostudies-literature
Project description:BACKGROUND:Taste and aroma, which are important organoleptic qualities of apricot (Prunus armeniaca L.) fruit, undergo rapid and substantial changes during ripening. However, the associated molecular mechanisms remain unclear. The goal of this study was to identify candidate genes for flavor compound metabolism and to construct a regulatory transcriptional network. RESULTS:We characterized the transcriptome of the 'Jianali' apricot cultivar, which exhibits substantial changes in flavor during ripening, at 50 (turning), 73 (commercial maturation) and 91 (full ripe) days post anthesis (DPA) using RNA sequencing (RNA-Seq). A weighted gene co-expression network analysis (WGCNA) revealed that four of 19 modules correlated highly with flavor compound metabolism (P?<?0.001). From them, we identified 1237 differentially expressed genes, with 16 intramodular hubs. A proposed pathway model for flavor compound biosynthesis is presented based on these genes. Two SUS1 genes, as well as SPS2 and INV1 were correlated with sugar biosynthesis, while NADP-ME4, two PK-like and mitochondrial energy metabolism exerted a noticeable effect on organic acid metabolism. CCD1 and FAD2 were identified as being involved in apocarotenoid aroma volatiles and lactone biosynthesis, respectively. Five sugar transporters (Sweet10, STP13, EDR6, STP5.1, STP5.2), one aluminum-activated malate transporter (ALMT9) and one ABCG transporter (ABCG11) were associated with the transport of sugars, organic acids and volatiles, respectively. Sixteen transcription factors were also highlighted that may also play regulatory roles in flavor quality development. CONCLUSIONS:Apricot RNA-Seq data were obtained and used to generate an annotated set of predicted expressed genes, providing a platform for functional genomic research. Using network analysis and pathway mapping, putative molecular mechanisms for changes in apricot fruit taste and aroma during ripening were elucidated.
| S-EPMC6332858 | biostudies-literature
Project description:BackgroundA complete and hardened endocarp is a typical trait of drupe fruits. However, the 'Liehe' (LE) apricot cultivar has a thin, soft, cleavable endocarp that represents 60.39% and 63.76% of the thickness and lignin content, respectively, of the 'Jinxihong' (JG) apricot (with normal hardened-endocarp). To understand the molecular mechanisms behind the LE apricot phenotype, comparative transcriptomes of Prunus armeniaca L. were sequenced using Illumina HiSeq™ 2500.ResultsIn this study, we identified 63,170 unigenes including 15,469 genes >1000 bp and 25,356 genes with Gene Function annotation. Pathway enrichment and expression patterns were used to characterize differentially expression genes. The DEGs encoding key enzymes involved in phenylpropanoid biosynthesis were significantly down-regulated in LE apricot. For example, CAD gene expression levels, encoding cinnamyl alcohol dehydrogenase, were only 1.3%, 0.7%, 0.2% and 2.7% in LE apricot compared with JG cultivar at 15, 21, 30, 49 days after full bloom (DAFB). Furthermore, transcription factors regulating secondary wall and lignin biosynthesis were identified. Especially for SECONDARY WALL THICKENING PROMOTING FACTOR 1 (NST 1), its expression levels in LE apricot were merely 2.8% and 9.3% compared with JG cultivar at 15 and 21 DAFB, respectively.ConclusionsOur comparative transcriptome analysis was used to understand the molecular mechanisms underlie the endocarp-cleaving phenotype in LE apricot. This new apricot genomic resource and the candidate genes provide a useful reference for further investigating the lignification during development of apricot endocarp. Transcription factors such as NST1 may regulate genes involved in phenylpropanoid pathway and affect development and lignification of the endocarp.
| S-EPMC5387262 | biostudies-literature
Project description:Graft incompatibility (GI) between the most popular Prunus rootstocks and apricot cultivars is one of the major problems for rootstock usage and improvement. Failure in producing long-leaving healthy grafts greatly affects the range of available Prunus rootstocks for apricot cultivation. Despite recent advances related to the molecular mechanisms of a graft-union formation between rootstock and scion, information on genetic control of this trait in woody plants is essentially missing because of a lack of hybrid crosses, segregating for the trait. In this study, we have employed the next-generation sequencing technology to generate the single-nucleotide polymorphism (SNP) markers and construct parental linkage maps for an apricot F1 population "Moniqui (Mo)" × "Paviot (Pa)" segregating for ability to form successful grafts with universal Prunus rootstock "Marianna 2624". To localize genomic regions associated with this trait, we genotyped 138 individuals from the "Mo × Pa" cross and constructed medium-saturated genetic maps. The female "Mo" and male "Pa" maps were composed of 557 and 501 SNPs and organized in eight linkage groups that covered 780.2 and 690.4 cM of genetic distance, respectively. Parental maps were aligned to the Prunus persica v2.0 genome and revealed a high colinearity with the Prunus reference map. Two-year phenotypic data for characters associated with unsuccessful grafting such as necrotic line (NL), bark and wood discontinuities (BD and WD), and an overall estimate of graft (in)compatibility (GI) were collected for mapping quantitative trait loci (QTLs) on both parental maps. On the map of the graft-compatible parent "Pa", two genomic regions on LG5 (44.9-60.8 cM) and LG8 (33.2-39.2 cM) were associated with graft (in)compatibility characters at different significance level, depending on phenotypic dataset. Of these, the LG8 QTL interval was most consistent between the years and supported by two significant and two putative QTLs. To our best knowledge, this is the first report on QTLs for graft (in)compatibility in woody plants. Results of this work will provide a valuable genomic resource for apricot breeding programs and facilitate future efforts focused on candidate genes discovery for graft (in)compatibility in apricot and other Prunus species.
| S-EPMC7933020 | biostudies-literature
Project description:In the present study, we identified and characterized the apricot (Prunus armeniaca L.) homologs of three dormancy-related genes, namely the ParCBF1 (C-repeat binding factor), ParDAM5 (dormancy-associated MADS-BOX) and ParDAM6 genes. All highly conserved structural motifs and the 3D model of the DNA-binding domain indicate an unimpaired DNA-binding ability of ParCBF1. A phylogenetic analysis showed that ParCBF1 was most likely homologous to Prunus mume and Prunus dulcis CBF1. ParDAM5 also contained all characteristic domains of the type II (MIKCC) subfamily of MADS-box transcription factors. The homology modeling of protein domains and a phylogenetic analysis of ParDAM5 suggest its functional integrity. The amino acid positions or small motifs that are diagnostic characteristics of DAM5 and DAM6 were determined. For ParDAM6, only a small part of the cDNA was sequenced, which was sufficient for the quantification of gene expression. The expression of ParCBF1 showed close association with decreasing ambient temperatures in autumn and winter. The expression levels of ParDAM5 and ParDAM6 changed according to CBF1 expression rates and the fulfillment of cultivar chilling requirements (CR). The concomitant decrease of gene expression with endodormancy release is consistent with a role of ParDAM5 and ParDAM6 genes in dormancy induction and maintenance. Cultivars with higher CR and delayed flowering time showed higher expression levels of ParDAM5 and ParDAM6 toward the end of endodormancy. Differences in the timing of anther developmental stages between early- and late-flowering cultivars and two dormant seasons confirmed the genetically and environmentally controlled mechanisms of dormancy release in apricot generative buds. These results support that the newly identified apricot gene homologs have a crucial role in dormancy-associated physiological mechanisms.
| S-EPMC6460505 | biostudies-literature
Project description:Ethylene metabolism is very important for climacteric fruit, and apricots are typical climacteric fruit. The activity of pectinase is closely related to fruit firmness, which further affects fruit quality. To better understand ethylene metabolism, pectinase activity and their molecular regulation mechanisms during the development and ripening of apricot fruit, ethylene metabolism, pectinase activity and the "Luntaibaixing" apricot fruit transcriptome were analyzed at different developmental stages. Ethylene metabolic precursors, enzyme activities and ethylene release increased during fruit development and ripening, with significant differences between the ripening stage and other stages (P < 0.05). Fruit firmness decreased significantly from the S1 to S5 stages, and polygalacturonase, pectin methylesterase, and pectin lyase activities were significantly higher in the S5 stage than in other stages. RNA sequencing (RNA-seq) analysis of fruit resulted in the identification of 22,337 unigenes and 6629 differentially expressed genes (DEGs) during development and ripening, of which 20,989 unigenes are annotated in public protein databases. In functional enrichment analysis, DEGs among the three stages were found to be involved in plant hormone signal transduction. Four key genes affecting ethylene metabolism, six key ethylene signal transduction genes and seven genes related to pectinase in apricot fruit were identified by KEGG pathway analysis. By RNA-sequencing, we not only clarified the molecular mechanism of ethylene metabolism during the ripening of "Luntaibaixing" apricot fruit but also provided a theoretical basis for understanding pectin metabolism in apricot fruit.
| S-EPMC8245559 | biostudies-literature