SEARCH · PubMed Health

Results for “fruit development”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

PubMed1999

A novel alkaline alpha-galactosidase from melon fruit with a substrate preference for raffinose

The cucurbits translocate the galactosyl-sucrose oligosaccharides raffinose and stachyose, therefore, alpha-galactosidase (alpha-D-galactoside galactohydrolase, EC 3.2.1.22) is expected to function as the initial enzyme of photoassimilate catabolism. However, the previously described alkaline alpha-galactosidase is specific for the tetrasaccharide stachyose, leaving raffinose catabolism in these tissues as an enigma. In this paper we report the partial purification and characterization of three alpha-galactosidases, including a novel alkaline alpha-galactosidase (form I) from melon (Cucumis melo) fruit tissue. The form I enzyme showed preferred activity with raffinose and significant activity with stachyose. Other unique characteristics of this enzyme, such as weak product inhibition by galactose (in contrast to the other alpha-galactosidases, which show stronger product inhibition), also impart physiological significance. Using raffinose and stachyose as substrates in the assays, the activities of the three alpha-galactosidases (alkaline form I, alkaline form II, and the acid form) were measured at different stages of fruit development. The form I enzyme activity increased during the early stages of ovary development and fruit set, in contrast to the other alpha-galactosidase enzymes, both of which declined in activity during this period. In the mature, sucrose-accumulating mesocarp, the alkaline form I enzyme was the major alpha-galactosidase present. We also observed hydrolysis of raffinose at alkaline conditions in enzyme extracts from other cucurbit sink tissues, as well as from young Coleus blumei leaves. Our results suggest different physiological roles for the alpha-galactosidase forms in the developing cucurbit fruit, and show that the newly discovered enzyme plays a physiologically significant role in photoassimilate partitioning in cucurbit sink tissue.

Journal Article↗

PubMed1977

Nutrition of a developing legume fruit: functional economy in terms of carbon, nitrogen, water.

The economy of functioning of the developing fruit of white lupin (Lupinus albus L.) is assessed quantitatively in relation to intake and usage of carbon, nitrogen, and water. Of every 100 units of carbon imported from the parent plant, 52 are incorporated into seeds, 37 into nonmobilizable material of the pod, and the remaining 11 lost as CO(2) to the atmosphere. An illuminated fruit can make net gains of CO(2) from the atmosphere during the photoperiods of all but the last 2 weeks of its life, suggesting that it is active in assimilation of CO(2) respired from pods and seeds. This conservation activity is important to carbon economy.Phloem supplies 98% of the fruit's carbon and 89% of its nitrogen. Most of the xylem's contribution enters early in development. Xylem and phloem supply similar sets of amino compounds, amides predominating. Ninety-six per cent of the fruit's nitrogen becomes incorporated into seeds. Sixteen per cent of the seed's nitrogen is mobilized from the senescing pod.The transpiration ratio of the fruit is 22.5 ml per gram dry matter accumulated. Xylem supplies 60% of a fruit's total water requirement and the equivalent of two-thirds of its transpiration loss. Phloem becomes prominent as a water donor once the seeds start to fill.The fruit exhibits a 31% conversion by weight of organic imports into food reserves of seeds. This entails an intake through vascular channels of 1756 mg sucrose and 384 mg amino compounds and an accumulation in seeds of 412 mg protein, 132 mg oil, and 110 mg perchloric acid-soluble carbohydrate.

Journal Article↗

PubMed2001

Abscisic acid-specific binding sites in the flesh of developing apple fruit.

Abscisic acid (ABA) specific-binding sites localized in the cytosol were identified and characterized in the flesh of developing apple (Malus pumila L. cv. Starkrimon) fruit. ABA binding activity was scarcely detectable in the microsomes but high ABA binding activity in the cytosolic fraction was detected. The ABA-binding sites possessed a protein nature with both active serine residues and thiol-groups of cysteine residues in their functional binding sites. ABA binding was shown to be saturable, reversible and of high affinity. A Scatchard plot provided evidence for two different ABA binding proteins, one with higher affinity (K(d)=2.3 nM) and the other with lower affinity (K(d)=58.8 nM). Phaseic acid, trans-ABA and (-)-ABA had essentially no affinity for the binding proteins, indicating their stereo-specificity to bind physiologically active cis-(+)-ABA. The time-course, pH- and temperature-dependence of the ABA-binding proteins were determined. It is hypothesized that the detected ABA-binding proteins may be putative ABA-receptors that mediate ABA signals during fruit development.

Abscisic Acid↗

PubMed1994

Regulation of Glutamate Dehydrogenase and Glutamine Synthetase in Avocado Fruit during Development and Ripening.

The activity, protein, and isoenzymic profiles of glutamate de-hydrogenase (GDH) and glutamine synthetase (GS) were studied during development and ripening of avocado (Percea americana Mill. cv Hass) fruit. During fruit development, the activity and protein content of both GDH and GS remained relatively constant. In contrast, considerable changes in these enzymes were observed during ripening of avocado fruit. The specific activity of GDH increased about 4-fold, coincident with a similar increase in GDH protein content and mRNA levels. On the other hand, GS specific activity showed a decline at the end of the ripening process. On the isoenzymic profile of GDH, changes in the prevalence of the seven isoenzymes were found, with a predominance of the more cathodal isoenzymes in the unripe and of the most anodal isoenzymes in the ripe fruit. Two-dimensional electrophoresis revealed that avocado fruit GDH consists of two subunits whose association gives rise to seven isoenzymes. The results support the view that the predominance of the more anodal isoenzymes in the overripe fruit was due to the accumulation of the [alpha]-polypeptide.

Journal Article↗

PubMed1988

A link between cell movement and gene expression argues that motility is required for cell-cell signaling during fruiting body development.

Nonmotile mutants of Myxococcus xanthus (Myxobacterales) failed to execute the morphogenetic movements required to shape a fruiting body. In addition, nonmotile mutants produced very few spores when plated for fruiting body development at cell densities appropriate for wild-type cells. At higher initial cell densities, the proportion of nonmotile cells that sporulate increased, indicating that one important function of motility in fruiting body development is to increase the local cell density. However, even at 10 times normal cell density, nonmotile cells sporulated at only 1% the wild-type level. This sporulation deficiency of nonmotile mutants accompanies an altered pattern of gene expression, monitored by using transcriptional fusions of lacZ to genes expressed at specific times during fruiting body development. Motility was not required for normal expression of five lac fusions that are expressed within the first 6 hr of fruiting-body development. However, the levels of expression from five lac fusions to later-expressed genes were reduced or abolished in nonmotile strains. beta-Galactosidase expression in these late Tn5 lac insertions was increased, and fruiting body development occurred in certain nonmotile strains that can be stimulated to move when mixed with a donor strain. This shows that motility itself is required because the stimulated cells are nonmotile genotypically. The nonmotile mutations had the same effect on developmental beta-galactosidase expression from these 10 lac fusions as an insertion mutation in the csg (formerly spoC) gene. csg mutants have a cell-cell interaction defect that blocks fruiting body development at approximately 6 hr. The similarity in the pattern of developmental expression of motility mutants and csg mutants suggests that motility is required for this csg-mediated cell-cell interaction.

Cell Movement↗

PubMed1999

Molecular and biochemical characterization of the involvement of cyclin-dependent kinase A during the early development of tomato fruit.

Following fruit set, the early development of tomato (Lycopersicon esculentum Mill.) fruit comprises two distinct phases: a cell division phase and a consecutive phase of cell expansion until the onset of ripening. In this study, we analyzed cytological and molecular changes characterizing these early phases of tomato fruit development. First we investigated the spatial and temporal regulation of the mitotic activity during fruit development. The DNA content of isolated nuclei from the different fruit tissues was determined by flow cytometry analysis. The results confirm the data of mitotic activity measurements and show that cell differentiation, leading to expanded cells, is characterized by endoreduplication. Second, we isolated two cDNAs, named Lyces;CDKA1 (accession no. Y17225) and Lyces;CDKA2 (accession no. Y17226), encoding tomato homologs of the cyclin-dependent kinase (CDK) p34(cdc2). Tomato CDKA gene expression was followed at both the transcriptional and translational levels during fruit development. The transcripts for Lyces;CDKA1 and Lyces;CDKA2 and the corresponding CDKA proteins are predominantly accumulated during the phase of cell division between anthesis and 5 d post anthesis (DPA). In whole fruits, the maximum CDK activity was obtained between 5 and 10 DPA. The determination of the kinase activity using protein extracts from the different fruit tissues was in agreement with mitotic activity analysis. It showed the particular disappearance of the activity in the gel tissue as early as 15 DPA. The overall data of CDK activity measurements suggest a strong post-translational regulation of CDK at the temporal and spatial levels during early tomato fruit development.

Amino Acid Sequence↗

PubMed2007

Major proteome variations associated with cherry tomato pericarp development and ripening.

Tomato (Solanum lycopersicum) is a model plant for studying fleshy fruit development. Several genetic and molecular approaches have been developed to increase our knowledge about the physiological basis of fruit growth, but very few data are yet available at the proteomic level. The main stages of fruit development were first determined through the dynamics of fruit diameter and pericarp cell number. Then, total proteins were extracted from pericarp tissue at six relevant developmental stages and separated by two-dimensional gel electrophoresis. Protein patterns were markedly different between stages. Proteins showing major variations were monitored. We identified 90 of 1,791 well-resolved spots either by matrix-assisted laser-desorption ionization time-of-flight peptide mass fingerprinting or liquid chromatography-mass spectrometry sequencing and expressed sequence tag database searching. Clustered correlation analysis results pointed out groups of proteins with similar expression profiles during fruit development. In young fruit, spots linked to amino acid metabolism or protein synthesis were mainly expressed during the cell division stage and down-regulated later. Some spots linked to cell division processes could be identified. During the cell expansion phase, spots linked to photosynthesis and proteins linked to cell wall formation transiently increased. In contrast, the major part of the spots related to C compounds and carbohydrate metabolism or oxidative processes were up-regulated during fruit development, showing an increase in spot intensity during development and maximal abundance in mature fruit. This was also the case for spots linked to stress responses and fruit senescence. We discuss protein variations, taking into account their potential role during fruit growth and comparing our results with already known variations at mRNA and metabolite-profiling levels.

Chromatography, Liquid↗

PubMed1990

Molecular cloning and sequencing of a cDNA for an auxin-repressed mRNA: correlation between fruit growth and repression of the auxin-regulated gene.

A complementary DNA (cDNA) library has been constructed in lambda gt 10 from poly(A)+ mRNA isolated from auxin-deprived strawberry receptacles. By differential plaque filter hybridization, a cDNA (lambda SAR5) to an auxin-repressed mRNA has been isolated. The expression of the auxin-repressed gene is studied at various stages of normal fruit development and in fruits of variant strawberry genotype using lambda SAR5 as a probe. Northern analyses of RNA isolated from pollinated and unpollinated fruits of various developmental stages revealed that mRNA corresponding to the lambda SAR5 clone is repressed during normal fruit development, and the level of lambda SAR5 mRNA is regulated by endogenous auxin. Furthermore, results with both normal and variant genotype strawberry fruit indicate that there is a positive correlation between growth of strawberry fruit and repression of mRNA corresponding to the lambda SAR5 clone. The lambda SAR5 cDNA has been sequenced and is 723 nucleotides in length. The deduced protein has 111 amino acid residues with a molecular mass of 12.5 kDa. The putative polypeptide starts at nucleotide position 20 and ends at 352. The molecular weight of the predicted polypeptide is in agreement with the molecular weight of the in vitro translated polypeptide of hybrid selected mRNA. A comparison of the nucleotide and deduced amino acid sequence of lambda SAR5 with nucleotide and protein sequences in data banks has not revealed any homology to known proteins.

Amino Acid Sequence↗

PubMed1998

[Studies on the morphology of fruit-body developing of Polyporus umbellatus].

OBJECTIVE: Studying the fruit-body development of polyporus umbellatus to reveal the life-cycle of this medicinal fungus. METHODS: Parts of materials treated by paraffin section, and examined under a light microscope; parts of materials by ultrathin section and observation under transmission electron microscope (TEM). RESULTS: The fruit-body consists of trimitic hyphae, including generative hyphae, skeletal hyphae and binding hyphae. Generative hyphae are characterized by thin walls, dense cytoplasmic contents. Skeletal hyphae are unbranched, thick-walled, and of a narrow lumen. Binding hyphae are much-branched, tending to weave themselves among the other hyphase of flesh. The morphology of basidiospore development was also discussed in this paper. CONCLUSIONS: The trimitic hyphae are the main component parts in the different developing stages of fruit-body of polyporus umbellatus.

Plants, Medicinal↗

PubMed1977

Subcellular Distributions of Isoenzymes in Fruits of a Normal Cultivar of Tomato and of the rin Mutant at Two Stages of Development.

Fruits of tomato (Lycopersicon esculentum Mill.) cv. Rutgers and of a nearly isogenic stock containing the ripening inhibitor gene rin harvested at green (66% mature) and ripe (107% mature) stages were studied for the subcellular distribution of isoenzymes using isoelectric focusing. The enzymes studied were peroxidases, esterases, phosphatases, phosphorylase, malate dehydrogenases, and IAA oxidases. During ripening of normal fruit the activities in the supernatant fraction of all of these enzymes, except malate dehydrogenase, decreased. In the particulate fractions some enzymes decreased while others increased in activity. The rin gene inhibited only some of the changes which occurred during ripening of normal fruit. It is postulated that changes in the degree to which enzymes are bound to membranes comprise one of the mechanisms by which the activities of enzymes are controlled in tomato pericarp, and that these membranes remain intact during ripening.

Journal Article↗

PubMedDate not supplied

Analysis of fruiting body development in the aggregative ciliate Sorogena stoianovitchae (Ciliophora, Colpodea).

The fruiting body-forming ciliate Sorogena stoianovitchae is a protist that is multicellular in one stage of its life cycle. When nutrient levels are depleted, a number of Sorogena cells aggregate beneath the water surface to form an aerial fruiting body. Based on morphologies and the inhibition of protein synthesis, fruiting body development is divided into five distinct stages: (1) aggregation before sunrise, (2) compact aggregation after sunrise, (3) secretion of mucous matrix, (4) stalk-elongation, and (5) completion of the fruiting-body. In the aggregation stage, the cells were trapped in a matrix material that stained orange with 4',6-diamino-2-phenylindole (DAPI), but differed from the mucous matrix in the later stage. A short interruption of the dark period, at 6-8 h after the onset of dark, inhibited fruiting body development. Irrespective of the length of the dark period (10-16 h), the cells remained in the aggregation stage until the beginning of the light period. Therefore, an uninterrupted dark period of more than 8 h is critical for the initial aggregation of cells, but subsequent development is triggered by light.

Animals↗

PubMed1982

Modeling C and N transport to developing soybean fruits.

Xylem sap and phloem exudates from detached leaves and fruit tips were collected and analyzed during early pod-fill in nodulated soybeans (Glycine max (L.) Merr. cv Wilkin) grown without (-N) and with (+N) NH(4)NO(3). Ureides were the predominant from (91%) of N transported in the xylem of -N plants, while amides (45%) and nitrate (23%) accounted for most of the N in the xylem of +N plants. Amino acids (44%) and ureides (36%) were the major N forms exported in phloem from leaves in -N plants, but amides (63%) were most important in +N plants. Based on the composition of fruit tip phloem, ureides (55% and 33%) and amides (26% and 47%) accounted for the majority of N imported by fruits of -N and +N plants, respectively.C:N weight ratios were lowest in xylem exudate (1.37 and 1.32), highest in petiole phloem (24.5 and 26.0), and intermediate in fruit tip exudate (12.6 and 12.1) for the -N and +N treatments, respectively. The ratios were combined with data on fruit growth and respiration to construct a model of C and N transport to developing fruits. The model indicates xylem to phloem transfer provides 35% to 52% of fruit N. Results suggest the phloem entering fruits oversupplies their N requirement so that 13% of the N imported is exported from fruit in the xylem.

Journal Article↗

PubMed2001

ADP-glucose pyrophosphorylase is located in the plastid in developing tomato fruit.

The subcellular location of activity and protein of ADP-glucose pyrophosphorylase (AGPase) in developing tomato (Lycopersicon esculentum) fruit was determined following a report that the enzyme might be present inside and outside the plastids in this organ. Plastids prepared from crude homogenates of columella and pericarp, the starch-accumulating tissues of developing fruit, contained 8% to 18% of the total activity of enzymes known to be confined to plastids, and 0.2% to 0.5% of the total activity of enzymes known to be confined to the cytosol. The proportion of the total activity of AGPase in the plastids was the same as that of the enzymes known to be confined to the plastid. When samples of plastid and total homogenate fractions were subjected to immunoblotting with an antiserum raised to AGPase, most or all of the protein detected was plastidial. Taken as a whole, these data provide strong evidence that AGPase is confined to the plastids in developing tomato fruit.

Blotting, Western↗

PubMed2003

Identification of an activator protein required for the induction of fruA, a gene essential for fruiting body development in Myxococcus xanthus.

Myxococcus xanthus exhibits social behavior and multicellular development. FruA is an essential transcription factor for fruiting body development in M. xanthus. In the present study, the upstream promoter region was found to be necessary for the induction of fruA expression during development. A cis-acting element required for the induction was identified and was located between nucleotides -154 and -107 with respect to the transcription initiation site. In addition, it was found that two binding sites exist within this element of the fruA promoter. By using DNA affinity column chromatography containing the cis-acting element, a fruA promoter-binding protein was purified. The purified protein was shown by N-terminal sequence analysis to be identical to MrpC, a protein identified previously by transposon insertion mutagenesis as an essential locus for fruiting body development [Sun, H. & Shi, W. (2001) J. Bacteriol. 183, 4786-4795]. Furthermore, fruA mRNA was not detectable in the mrpC::km strain, demonstrating that MrpC is essential for fruA expression. Moreover, mutational analysis of the binding sites for MrpC in the fruA promoter indicates that binding of MrpC activates transcription of fruA in vivo. This report provides evidence for a direct molecular interaction involved in temporally regulated gene expression in M. xanthus.

Amino Acid Sequence↗

PubMed2003

Antisense suppression of a beta-galactosidase gene (TB G6) in tomato increases fruit cracking.

Antisense suppression of a tomato beta-galactosidase gene (TBG6) was used to study its role in fruit development, cell wall-modification, and fruit firmness. TBG6 mRNA is highly abundant during the early stages of fruit development, but the levels decline sharply after the breaker stage with the start of the respiratory climacteric and a concomitant increase in ethylene production. Two antisense lines were obtained with significantly reduced levels of TBG6 mRNA at all stages of fruit development. At 30 d after pollination (dap), TBG6 mRNA levels were reduced by up to 98% and 88% in lines 6-2 and 6-10, respectively. Morphological phenotypes observed in the antisense lines included increased fruit cracking, reduced locular space, and a doubling in the thickness of the fruit cuticle. Two biochemical changes in antisense lines, compared with wild-type lines, were a reduction of exo-galactanase activity at the breaker +3 d stage and a reduction in the cell wall galactosyl content at the 20 dap stage. In addition, transgenic lines exhibited a 35-39% reduction in fruit firmness at the 20 dap stage, but their texture was equivalent to the wild type at 30 dap and beyond. Although the exact function of the TBG6 product is still unknown, these results implicate an important role for this enzyme in early fruit growth and development in tomato.

Cell Wall↗

PubMed1991

Purification and characterization of two ribonucleases from developing tomato fruit.

Two neutral ribonucleases have been purified from developing tomato fruit. Their activity is maximal 5 days after anthesis, declines during maturation, and then increases slightly in the mature green through breaker stages. The ribonucleases Tf1 and Tf2 have molecular weights of 59 and 29 K, respectively, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and are glycoproteins. The reduced and denatured Tf1 is composed of two subunits, 30 and 29 K, of which only the 30-K subunit displays ribonuclease activity after renaturation. Reduced and denatured Tf2 is a single 29-K polypeptide that is renaturable to an active ribonuclease. Only the 30-K, active subunit of Tf1 is immunologically cross-reactive with Tf2. Both ribonucleases are cyclyzing endoribonucleases with a strong preference for cleavage at pyrimidine residues, thus generating oligonucleotide products ending with pyrimidine 2',3'-cyclic phosphate. These tomato fruit ribonucleases share a number of properties in common with the S-glycoprotein ribonucleases that are involved in self-incompatibility reactions in some solanaceous plants.

Amino Acid Sequence↗

PubMed2006

Comparative gene expression analysis of fruiting body development in two filamentous fungi.

The ascomycete Pyronema confluens is a member of the Pezizales and readily forms fruiting bodies under laboratory conditions. Here, we report the first molecular analysis of fruiting body development in this filamentous fungus. Two P. confluens cDNA libraries were generated, one derived from mycelium undergoing sexual development, and the other from vegetative mycelium. From each library, 96 clones were end-sequenced, resulting in the identification of 132 different genes. Expression studies of 10 P. confluens genes by quantitative real-time PCR identified seven genes that are transcriptionally up- or down regulated during sexual development when compared with vegetative growth. As a first step towards a comparison of gene expression during fruiting body development in different filamentous fungi, transcript levels of the corresponding homologs from the distantly related ascomycete Sordaria macrospora were analyzed by quantitative real-time PCR. The analyses revealed similar expression patterns during sexual development for several of the S. macrospora genes when compared with P. confluens.

Ascomycota↗

PubMed2002

Isolation and characterization of six peach cDNAs encoding key proteins in organic acid metabolism and solute accumulation: involvement in regulating peach fruit acidity.

As in many other fleshy fruits, the predominant organic acids in ripe peach (Prunus persica (L.) Batsch) fruit are malic and citric acids. The accumulation of these metabolites in fruit flesh is regulated during fruit development. Six peach fruit-related genes implicated in organic acid metabolism (mitochondrial citrate synthase; cytosolic NAD-dependent malate dehydrogenase, and cytosolic NADP-dependent isocitrate dehydrogenase) and storage (vacuolar proton translocating pumps: one vacuolar H+-ATPase, and two vacuolar H+-pyrophosphatases) were cloned. Five of these peach genes were homologous to genes isolated from fruit in other fleshy fruit species. Phylogenetic and expression analyses suggested the existence of a particular vacuolar pyrophosphatase highly expressed in fruit. The sixth gene was the first cytosolic NAD-dependent malate dehydrogenase gene isolated from fruit. Gene expression was studied during the fruit development of two peach cultivars, a normal-acid (Fantasia) and a low-acid (Jalousia) cultivar. The overall expression patterns of the organic acid-related genes appeared strikingly similar for the two cultivars. The genes involved in organic acid metabolism showed a stronger expression in ripening fruit than during the earlier phases of development, but their expression patterns were not necessarily correlated with the changes in organic acid contents. The tonoplast proton pumps showed a biphasic expression pattern more consistent with the patterns of organic acid accumulation, and the tonoplast pyrophosphatases were more highly expressed in the fruit of the low-acid cultivar during the second rapid growth phase of the fruit.

Journal Article↗