Systematic Analysis of Sugar Unloading And Accumulation Mechanism In Sucrose- And Hexose- Accumulating Tomato Fruits

Abstract Sugar is the key factor in the formation of fruit quality. Hexose is the main form of sugar accumulated in ordinary cultivated tomatoes, while a small number of wild-type tomato varieties can also accumulate sucrose. Although several studies have focused on wild sucrose-accumulating tomatoes, the sugar accumulation mechanism in tomato is still unclear. Here, two cherry tomatoes lines that accumulated sucrose and hexose respectively were selected to analyze the assimilates unloading pathway and sugar accumulation mechanism using CF tracing, cytological observation, proteomics methods, etc. The results indicated that the later stages of fruit development were key stages for sugar accumulation, and sucrose-accumulating (S) cherry tomatoes had higher sucrose contents in the fruits, while hexose-accumulating (H) cherry tomatoes accumulated more glucose, fructose and starch. The unloading pathway of assimilates in the S cherry tomato was switched from apoplastic to symplastic during fruit development, and the opposite was true in the H type. Plasmodesmata transport may be the main means of sucrose accumulation and high activity or expression levels of acid invertase (AI) and SUT1 may be important factors in hexose accumulation in H and S cherry tomatoes, respectively. In addition to sugar metabolism, photosynthesis, fatty acid metabolism and other secondary metabolism pathways also play important roles in sugar accumulation. This study provides detailed evidence for the tomato sugar accumulation mechanism from the perspective of cell structure, physiology and molecular biology, providing a theoretical basis for the improvement of tomato quality and aiding the utilization of tomato genetic resources.

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Sugar Metabolism and Pineapple Flesh Translucency

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.125.5.558 ◽

2000 ◽

Vol 125 (5) ◽

pp. 558-562 ◽

Cited By ~ 21

Author(s):

Ching-Cheng Chen ◽

Robert E. Paull

Keyword(s):

Fruit Development ◽

Water Movement ◽

Sugar Metabolism ◽

Sucrose Phosphate Synthase ◽

Solute Concentration ◽

Soluble Solids ◽

Ananas Comosus ◽

Sugar Accumulation ◽

Young Fruit ◽

Fruit Flesh

Sugar accumulation and the activities of sugar metabolizing enzymes were related to the occurrence of pineapple [Ananas comosus (L.) Merr.] flesh translucency. During early fruit development, glucose and fructose were the predominant sugars. Sucrose began to accumulate 6 weeks before harvest at a higher rate in the fruitlet than in the interfruitlet tissue. Electrolyte leakage from pineapple flesh increased rapidly from 6 weeks before harvest and paralleled sucrose accumulation. Sucrose synthase activity was high in young fruit flesh and declined with fruit development, while the activity of sucrose phosphate synthase was relatively low and constant throughout fruit development. The activities of acid invertase, neutral invertase, and cell-wall invertase (CWI) were high in the young fruit flesh and declined to very low levels 6 weeks before harvest when sucrose started to accumulate. CWI activity increased again, more in the fruitlet than in the interfruitlet tissue, 4 weeks before harvest. Removal of 1/3 of the plant leaves 3 weeks before harvest significantly reduced fruit flesh total soluble solids, CWI activity, and translucency incidence at harvest. The activity of CWI in translucent fruit flesh was significantly higher than in opaque fruit flesh at harvest. CWI activities in the basal section of pineapple flesh and in the fruitlet, where translucency first occurred, were higher than those in the apical section and in the interfruitlet tissue, respectively. Results support the hypothesis that high CWI activity in pineapple flesh at the later stage of fruit development enhances sucrose unloading into the fruit flesh apoplast, leading to increased apoplastic solute concentration (decreased solute potential) and subsequent water movement into the apoplast. This, in turn, may reduce porosity and lead to increased fruit flesh translucency.

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Sugar Metabolism and Relative Enzyme Activities during Fruit Development and Ripening of Papaya

HortScience ◽

10.21273/hortsci.32.3.443c ◽

1997 ◽

Vol 32 (3) ◽

pp. 443C-443

Author(s):

Lili Zhou ◽

Robert E. Paull

Keyword(s):

Fruit Development ◽

Dry Matter ◽

Sugar Metabolism ◽

Invertase Activity ◽

Acid Invertase ◽

Soluble Solids ◽

Sugar Accumulation ◽

Sucrose Synthetase ◽

Activity Of Enzymes ◽

Days After Anthesis

This study examined the relationship between the activity of fruit enzymes involved in metabolizing sucrose and sugar accumulation during fruit development, to clarify the role of these key enzymes in sugar accumulation in papaya fruit. Papaya fruit (Carica papaya L. cv. Sunset) were harvested from 14 to 140 days after anthesis (DAA). Fruit dry matter persent, total soluble solids (TSS), and sugar composition and the activity of enzymes: sucrose phosphate synthetase (SPS), sucrose synthetase (SS), and acid invertase were measured. `Sunset' papaya matured 140 days after anthesis during the Hawaii summer season and in about 180 days in cool season on the same plant. Fruit flesh dry matter persent, TSS, and total sugar did not significantly increase until 30 days before harvest. Sucrose synthetase was very high 2 weeks post-anthesis, then decreased to less than one-third in 42 to 56 DAA, then remained relatively low during the rest of fruit development. Seven to 14 days before fruit maturation, SS increased about 30% at the same time as sucrose accumulation in the fruit. Acid invertase activity was very low in the young fruit and increased more than 10-fold 42 to 14 days before maturation. SPS activity remained very low throughout the fruit development and was about 40% higher in mature-green fruit. The potential roles of invertase and sucrose synthetase in sugar accumulation will be discussed.

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Enrichment of kinase fusions in ESR1 wild-type, metastatic breast cancer revealed by a systematic analysis of 4854 patients

Annals of Oncology ◽

10.1016/j.annonc.2020.04.008 ◽

2020 ◽

Vol 31 (8) ◽

pp. 991-1000 ◽

Cited By ~ 3

Author(s):

D.S. Ross ◽

B. Liu ◽

A.M. Schram ◽

P. Razavi ◽

S.M. Lagana ◽

...

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Metastatic Breast ◽

Wild Type ◽

Systematic Analysis

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Short-Term Effects of γ-Irradiation on 1-Aminocyclopropane-1-Carboxylic Acid Metabolism in Early Climacteric Cherry Tomatoes

PLANT PHYSIOLOGY ◽

10.1104/pp.92.3.577 ◽

1990 ◽

Vol 92 (3) ◽

pp. 577-581 ◽

Cited By ~ 28

Author(s):

Christian Larrigaudière ◽

Alain Latché ◽

Jean Claude Pech ◽

Christian Triantaphylidès

Keyword(s):

Carboxylic Acid ◽

Acid Metabolism ◽

Short Term ◽

Γ Irradiation ◽

Cherry Tomatoes ◽

Short Term Effects

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Identification of a DNA region required for growth of Pseudomonas syringae pv. tomato on tomato plants

Canadian Journal of Microbiology ◽

10.1139/m92-144 ◽

1992 ◽

Vol 38 (9) ◽

pp. 883-890 ◽

Cited By ~ 2

Author(s):

Dennis P. Jackson ◽

Douglas A. Gray ◽

Vincent L. Morris ◽

Diane A. Cuppels

Keyword(s):

Organic Acids ◽

Pseudomonas Syringae ◽

Acid Metabolism ◽

Carbon Sources ◽

Hypersensitive Reaction ◽

Wild Type ◽

In Planta ◽

Tomato Plants ◽

Tartaric Acids ◽

Nonpathogenic Strain

The prototrophic Pseudomonas syringae pv. tomato mutant DC3481, which is the result of a single-site Tn5 insertion, cannot grow and cause disease on tomato plants and cannot use the major organic acids of tomato, i.e., citric, malic, succinic, and tartaric acids, as sole carbon sources. Although nonpathogenic, strain DC3481 can still induce a hypersensitive reaction in nonhost plants. We have identified a 30-kb fragment of P. syringae pv. tomato wild-type DNA that can complement this mutant. EcoRI fragments from this region were subcloned and individually subjected to functional complementation analysis. The 3.8-kb fragment, which was the site of the Tn5 insertion, restored pathogenicity and the ability to use all the major organic acids of tomato as carbon sources. It shares sequence homology with several P. syringae pathovars but not other bacterial tomato pathogens. Our results indicate that sequences on the 3.8-kb EcoRI fragment are required for both the ability to grow on tomato leaves (and thus cause disease) and the utilization of carboxylic acids common to tomato. The 3.8-kb fragment may contain a sequence (or sequences) that regulates both traits. Key words: Pseudomonas syringae pv. tomato, phytopathogenicity, Tn5, tricarboxylic acid metabolism, bacterial speck, growth in planta.

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The Tolerance of Salinity in Rice Requires the Presence of a Functional Copy of FLN2

Biomolecules ◽

10.3390/biom10010017 ◽

2019 ◽

Vol 10 (1) ◽

pp. 17 ◽

Cited By ~ 1

Author(s):

Guang Chen ◽

Jiang Hu ◽

Liuliu Dong ◽

Dali Zeng ◽

Longbiao Guo ◽

...

Keyword(s):

Salinity Stress ◽

Salinity Tolerance ◽

Sugar Metabolism ◽

Invertase Activity ◽

Leaf Sheath ◽

Japonica Rice ◽

Wild Type ◽

Bisphosphate Carboxylase ◽

Genes Encoding ◽

Knockout Line

A panel of ethane-methyl-sulfonate-mutagenized japonica rice lines was grown in the presence of salinity in order to identify genes required for the expression of salinity tolerance. A highly nontolerant selection proved to harbor a mutation in FLN2, a gene which encodes fructokinase-like protein2. Exposure of wild-type rice to salinity up-regulated FLN2, while a CRISPR/Cas9-generated FLN2 knockout line was hypersensitive to the stress. Both ribulose 1,5-bisphosphate carboxylase/oxygenase activity and the abundance of the transcript generated by a number of genes encoding components of sucrose synthesis were lower in the knockout line than in wild-type plants’ leaves, while the sucrose contents of the leaf and root were, respectively, markedly increased and decreased. That sugar partitioning to the roots was impaired in FLN2 knockout plants was confirmed by the observation that several genes involved in carbon transport were down-regulated in both the leaf and in the leaf sheath. The levels of sucrose synthase, acid invertase, and neutral invertase activity were distinctly lower in the knockout plants’ roots than in those of wild-type plants, particularly when the plants were exposed to salinity stress. The compromised salinity tolerance exhibited by the FLN2 knockout plants was likely a consequence of an inadequate supply of the assimilate required to support growth, a problem which was rectifiable by providing an exogenous supply of sucrose. The conclusion was that FLN2, on account of its influence over sugar metabolism, is important in the context of seedling growth and the rice plant’s response to salinity stress.

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Myostatin regulates fatty acid desaturation and fat deposition through MEF2C/miR222/SCD5 cascade in pigs

Communications Biology ◽

10.1038/s42003-020-01348-8 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Hongyan Ren ◽

Wei Xiao ◽

Xingliang Qin ◽

Gangzhi Cai ◽

Hao Chen ◽

...

Keyword(s):

Transcription Factor ◽

Fatty Acid ◽

Fatty Acid Metabolism ◽

Acid Metabolism ◽

Muscle Growth ◽

Subcutaneous Fat ◽

Fat Deposition ◽

Wild Type ◽

Binding Prediction ◽

Stearoyl Coa Desaturase

Abstract Myostatin (MSTN), associated with the “double muscling” phenotype, affects muscle growth and fat deposition in animals, whereas how MSTN affects adipogenesis remains to be discovered. Here we show that MSTN can act through the MEF2C/miR222/SCD5 cascade to regulate fatty acid metabolism. We generated MSTN-knockout (KO) cloned Meishan pigs, which exhibits typical double muscling trait. We then sequenced transcriptome of subcutaneous fat tissues of wild-type (WT) and MSTN-KO pigs, and intersected the differentially expressed mRNAs and miRNAs to predict that stearoyl-CoA desaturase 5 (SCD5) is targeted by miR222. Transcription factor binding prediction showed that myogenic transcription factor 2C (MEF2C) potentially binds to the miR222 promoter. We hypothesized that MSTN-KO upregulates MEF2C and consequently increases the miR222 expression, which in turn targets SCD5 to suppress its translation. Biochemical, molecular and cellular experiments verified the existence of the cascade. This novel molecular pathway sheds light on new targets for genetic improvements in pigs.

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Overcoming the Bitter Taste of Oils Enriched in Fatty Acids to Obtain Their Effects on the Heart in Health and Disease

Nutrients ◽

10.3390/nu11051179 ◽

2019 ◽

Vol 11 (5) ◽

pp. 1179

Author(s):

Aleksandra Stamenkovic ◽

Riya Ganguly ◽

Michel Aliani ◽

Amir Ravandi ◽

Grant N. Pierce

Keyword(s):

Cardiovascular Disease ◽

Fatty Acids ◽

Fatty Acid ◽

Acid Metabolism ◽

Cell Structure ◽

Primary Source ◽

Role Changes ◽

Disease States ◽

Energy Demands ◽

Health And Disease

Fatty acids come in a variety of structures and, because of this, create a variety of functions for these lipids. Some fatty acids have a role to play in energy metabolism, some help in lipid storage, cell structure, the physical state of the lipid, and even in food stability. Fatty acid metabolism plays a particularly important role in meeting the energy demands of the heart. It is the primary source of myocardial energy in control conditions. Its role changes dramatically in disease states in the heart, but the pathologic role these fatty acids play depends upon the type of cardiovascular disease and the type of fatty acid. However, no matter how good a food is for one’s health, its taste will ultimately become a deciding factor in its influence on human health. No food will provide health benefits if it is not ingested. This review discusses the taste characteristics of culinary oils that contain fatty acids and how these fatty acids affect the performance of the heart during healthy and diseased conditions. The contrasting contributions that different fatty acid molecules have in either promoting cardiac pathologies or protecting the heart from cardiovascular disease is also highlighted in this article.

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Apically Exposed, Tight Junction-Associated β1-Integrins Allow Binding and YopE-Mediated Perturbation of Epithelial Barriers by Wild-Type Yersinia Bacteria

Infection and Immunity ◽

10.1128/iai.68.9.5335-5343.2000 ◽

2000 ◽

Vol 68 (9) ◽

pp. 5335-5343 ◽

Cited By ~ 46

Author(s):

Farideh Tafazoli ◽

Anna Holmström ◽

Åke Forsberg ◽

Karl-Eric Magnusson

Keyword(s):

Epithelial Cells ◽

Tight Junction ◽

Tight Junctions ◽

Yersinia Pseudotuberculosis ◽

Cell Structure ◽

Wild Type ◽

Filamentous Actin ◽

Basolateral Membranes ◽

Contact Points ◽

Β1 Integrins

ABSTRACT Using polarized epithelial cells, primarily MDCK-1, we assessed the mode of binding and effects on epithelial cell structure and permeability of Yersinia pseudotuberculosis yadA-deficient mutants. Initially, all bacteria except the invasin-deficient (inv) mutant adhered apically to the tight junction areas. These contact points of adjacent cells displayed β1-integrins together with tight junction-associated ZO-1 and occludin proteins. Indeed, β1-integrin expression was maximal in the tight junction area and then gradually decreased along the basolateral membranes. Wild-type bacteria also opened gradually the tight junction to paracellular permeation of different-sized markers, viz., 20-, 40-, and 70-kDa dextrans and 45-kDa ovalbumin, as well as to their own translocation between adjacent cells in intimate contact with β1-integrins. The effects on the epithelial cells and their barrier properties could primarily be attributed to expression of the Yersinia outer membrane protein YopE, as the yopE mutant bound but caused no cytotoxicity. Moreover, the apical structure of filamentous actin (F-actin) was disturbed and tight junction-associated proteins (ZO-1 and occludin) were dispersed along the basolateral membranes. It is concluded that the Yersinia bacteria attach to β1-integrins at tight junctions. Via this localized injection of YopE, they perturb the F-actin structure and distribution of proteins forming and regulating tight junctions. Thereby they promote paracellular translocation of bacteria and soluble compounds.

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