scholarly journals Plasma membrane-localized SlSWEET7a and SlSWEET14 regulate sugar transport and storage in tomato fruits

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xinsheng Zhang ◽  
Chaoyang Feng ◽  
Manning Wang ◽  
Tianlai Li ◽  
Xin Liu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Sugar Content ◽  
Sugar Transport ◽  
Invertase Activity ◽  
Vascular Bundles ◽  
Tomato Fruits ◽  
Sugar Transporters ◽  
Potential Strategy ◽  
And Storage

AbstractSugars, especially glucose and fructose, contribute to the taste and quality of tomato fruits. These compounds are translocated from the leaves to the fruits and then unloaded into the fruits by various sugar transporters at the plasma membrane. SWEETs, are sugar transporters that regulate sugar efflux independently of energy or pH. To date, the role of SWEETs in tomato has received very little attention. In this study, we performed functional analysis of SlSWEET7a and SlSWEET14 to gain insight into the regulation of sugar transport and storage in tomato fruits. SlSWEET7a and SlSWEET14 were mainly expressed in peduncles, vascular bundles, and seeds. Both SlSWEET7a and SlSWEET14 are plasma membrane-localized proteins that transport fructose, glucose, and sucrose. Apart from the resulting increase in mature fruit sugar content, silencing SlSWEET7a or SlSWEET14 resulted in taller plants and larger fruits (in SlSWEET7a-silenced lines). We also found that invertase activity and gene expression of some SlSWEET members increased, which was consistent with the increased availability of sucrose and hexose in the fruits. Overall, our results demonstrate that suppressing SlSWEET7a and SlSWEET14 could be a potential strategy for enhancing the sugar content of tomato fruits.

scholarly journals Overexpression of Melon Tonoplast Sugar Transporter CmTST1 Improved Root Growth under High Sugar Content

2020 ◽  
Vol 21 (10) ◽  
pp. 3524
Author(s):  
Baiyi Lu ◽  
Suying Wen ◽  
Peilu Zhu ◽  
Haishun Cao ◽  
Yixuan Zhou ◽  
...  
Keyword(s):  
Root Growth ◽  
Intracellular Transport ◽  
Sugar Content ◽  
Ectopic Expression ◽  
Sugar Transport ◽  
Sugar Transporters ◽  
Source To Sink ◽  
High Sugar Content ◽  
High Level

Sugar allocation is based on the source-to-sink and intracellular transport between different organelles, and sugar transporters are usually involved in these processes. Tonoplast sugar transporters (TST) are responsible for transporting sugar into vacuoles; however, the role of TSTs in root growth and the response to abiotic stress is poorly studied. Here, RNA analysis and promoter-β-glucuronidase staining revealed that a melon TST1 gene (CmTST1) is highly expressed in the roots. The sugar feeding experiment results showed that the expression of CmTST1 in the roots was induced by a relatively high level of sucrose (6%), glucose (3%), and fructose (3%). The ectopic overexpression of CmTST1 in Arabidopsis improved the root and shoot growth of seedlings under high exogenous sugar stress. Furthermore, the ectopic expression of CmTST1 promoted the expression of plasma membrane-located sugar transporters. We proposed that CmTST1 plays a key role in importing sugar transport into the vacuoles of roots in response to metabolic demands to maintain cytosolic sugar homeostasis.

scholarly journals Increase in Phloem Area in the Tomato Hawaiian Skirt Mutant Is Associated with Enhanced Sugar Transport

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 932
Author(s):  
Fabien Lombardo ◽  
Pietro Gramazio ◽  
Hiroshi Ezura
Keyword(s):  
Gene Function ◽  
Sugar Content ◽  
Sugar Transport ◽  
Vascular Bundles ◽  
Phloem Exudate ◽  
Tomato Fruits ◽  
Rice Mutant ◽  
Knowing That ◽  
Distinct Increase ◽  
Panicle Architecture

The Hawaiian skirt (HWS) gene has been described in Arabidopsis, rice, tomato and poplar where it seems to perform distinct functions with relatively little overlap. In tomato, alteration of the gene function confers facultative parthenocarpy, thought to be a consequence of changes in the microRNA metabolism. In the rice mutant, improvement in panicle architecture is associated with an increase in grain yield. Knowing that hws tomato fruits show a higher Brix level, it was suspected that vascular bundles might also be altered in this species, in a similar fashion to the rice phenotype. The pedicel structure of the hws-1 line was therefore examined under the microscope and sugar concentrations from phloem exudate were determined in an enzymatic assay. A distinct increase in the phloem area was observed as well as a higher sugar content in mutant phloem exudates, which is hypothesized to contribute to the high Brix level in the mutant fruits. Furthermore, the described phenotype in this study bridges the gap between Arabidopsis and rice phenotypes, suggesting that the modulation of the microRNA metabolism by HWS influences traits of agricultural interest across several species.

scholarly journals VvSWEET10 Mediates Sugar Accumulation in Grapes

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 255 ◽  
Author(s):  
Zhan Zhang ◽  
Luming Zou ◽  
Chong Ren ◽  
Fengrui Ren ◽  
Yi Wang ◽  
...  
Keyword(s):  
Sugar Content ◽  
Sugar Transport ◽  
Grape Berry ◽  
Critical Event ◽  
Sugar Accumulation ◽  
Sugar Transporters ◽  
Market Values ◽  
Berry Quality ◽  
Sugar Levels

Sugar accumulation is a critical event during grape berry ripening that determines the grape market values. Berry cells are highly dependent on sugar transporters to mediate cross-membrane transport. However, the role of sugar transporters in improving sugar accumulation in berries is not well established in grapes. Herein we report that a Sugars Will Eventually be Exported Transporter (SWEET), that is, VvSWEET10, was strongly expressed at the onset of ripening (véraison) and can improve grape sugar content. VvSWEET10 encodes a plasma membrane-localized transporter, and the heterologous expression of VvSWEET10 indicates that VvSWEET10 is a hexose-affinity transporter and has a broad spectrum of sugar transport functions. VvSWEET10 overexpression in grapevine calli and tomatoes increased the glucose, fructose, and total sugar levels significantly. The RNA sequencing results of grapevine transgenic calli showed that many sugar transporter genes and invertase genes were upregulated and suggest that VvSWEET10 may mediate sugar accumulation. These findings elucidated the role of VvSWEET10 in sugar accumulation and will be beneficial for the improvement of grape berry quality in the future.

THE ROLE OF POLYPHOSPHATES IN SUGAR TRANSPORT ACROSS THE PLASMA MEMBRANE OF YEAST

1985 ◽  
pp. 377-384 ◽  
Author(s):  
J. Van Steveninck ◽  
J.P.F. Tijssen ◽  
T.M.A.R. Dubbelman ◽  
P.J.A. Van den Broek
Keyword(s):  
Plasma Membrane ◽  
Sugar Transport

The regulation of assimilate allocation and transport

2000 ◽  
Vol 27 (6) ◽  
pp. 583 ◽  
Author(s):  
Hanjo Hellmann ◽  
Laurence Barker ◽  
Dietmar Funck ◽  
Wolf B. Frommer
Keyword(s):  
Higher Plants ◽  
Sugar Transport ◽  
Long Distance ◽  
Regulatory Pathways ◽  
Sugar Transporters ◽  
E Coli ◽  
Long Distance Transport ◽  
N Metabolism ◽  
C And N ◽  
And Storage

In higher plants, sugars possess multiplefunctions: transport and storage of carbon and energy as well as signalmolecules. A variety of sugar transporters have been cloned that showdifferential expression between source and sink tissues. Expression of thesetransporters is highly regulated, according to the local metabolic status andthe demands of long distance transport. Very little knowledge is available onmechanisms underlying the regulation of sugar transporter expression inplants. Studies in E. coli, yeast and mammals haveunravelled complex regulatory pathways with crosstalk between sugar transportand metabolism. Recent studies in plants provide increasing evidence for theexistence of similar regulatory mechanisms. In many cases, connections havebeen found between C-and N-metabolism, implicating a tight network of signaltransduction and metabolism. Some aspects of this network are presented inthis review, emphasising sugar transport and sugar signaltransduction.

scholarly journals Involvement of SUT1 and SUT2 Sugar Transporters in the Impairment of Sugar Transport and Changes in Phloem Exudate Contents in Phytoplasma-Infected Plants

2021 ◽  
Vol 22 (2) ◽  
pp. 745
Author(s):  
Federica De Marco ◽  
Brigitte Batailler ◽  
Michael R. Thorpe ◽  
Frédérique Razan ◽  
Rozenn Le Hir ◽  
...  
Keyword(s):  
Metabolite Profiling ◽  
Sugar Transport ◽  
Starch Accumulation ◽  
Primary Metabolism ◽  
Phloem Exudate ◽  
Phloem Sap ◽  
Sugar Transporters ◽  
Abnormal Growth ◽  
Sucrose Transporters

Phytoplasmas inhabit phloem sieve elements and cause abnormal growth and altered sugar partitioning. However, how they interact with phloem functions is not clearly known. The phloem responses were investigated in tomatoes infected by “Candidatus Phytoplasma solani” at the beginning of the symptomatic stage, the first symptoms appearing in the newly emerged leaf at the stem apex. Antisense lines impaired in the phloem sucrose transporters SUT1 and SUT2 were included. In symptomatic sink leaves, leaf curling was associated with higher starch accumulation and the expression of defense genes. The analysis of leaf midribs of symptomatic leaves indicated that transcript levels for genes acting in the glycolysis and peroxisome metabolism differed from these in noninfected plants. The phytoplasma also multiplied in the three lower source leaves, even if it was not associated with the symptoms. In these leaves, the rate of phloem sucrose exudation was lower for infected plants. Metabolite profiling of phloem sap-enriched exudates revealed that glycolate and aspartate levels were affected by the infection. Their levels were also affected in the noninfected SUT1- and SUT2-antisense lines. The findings suggest the role of sugar transporters in the responses to infection and describe the consequences of impaired sugar transport on the primary metabolism.

The osmotolerant fructophilic yeast Zygosaccharomyces rouxii employs two plasma-membrane fructose uptake systems belonging to a new family of yeast sugar transporters

Microbiology ◽  
2011 ◽  
Vol 157 (2) ◽  
pp. 601-608 ◽  
Author(s):  
Maria José Leandro ◽  
Hana Sychrová ◽  
Catarina Prista ◽  
Maria C. Loureiro-Dias
Keyword(s):  
Plasma Membrane ◽  
Diffusion Mechanism ◽  
Sugar Transport ◽  
High Capacity ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Sugar Transporters ◽  
Zygosaccharomyces Rouxii ◽  
New Family ◽  
Spoilage Yeasts

Owing to its high resistance to weak-acid preservatives and extreme osmotolerance, Zygosaccharomyces rouxii is one of the main spoilage yeasts of sweet foods and beverages. In contrast with Saccharomyces cerevisiae, Z. rouxii is a fructophilic yeast; it consumes fructose faster than glucose. So far, to our knowledge, no specific Z. rouxii proteins responsible for this fructophilic behaviour have been characterized. We have identified two genes encoding putative fructose transporters in the Z. rouxii CBS 732 genome. Heterologous expression of these two Z. rouxii ORFs in a S. cerevisiae strain lacking its own hexose transporters (hxt-null) and subsequent kinetic analysis of sugar transport showed that both proteins are functionally expressed at the plasma membrane: ZrFfz1 is a high-capacity fructose-specific facilitator (K m∼400 mM and V max∼13 mmol h−1 g−1) and ZrFfz2 is a facilitator transporting glucose and fructose with similar capacity and affinity (K m∼200 mM and V max∼4 mmol h−1 g−1). These two proteins together with the Zygosaccharomyces bailii Ffz1 fructose-specific transporter belong to a new family of sugar transport systems mediating the uptake of hexoses via the facilitated diffusion mechanism, and are more homologous to drug/H+ antiporters (regarding their primary protein structure) than to other yeast sugar transporters of the Sugar Porter family.

scholarly journals Sugar transport in arbuscular mycorrhizal symbiosis

2009 ◽  
Vol 89 (2) ◽  
pp. 257-263 ◽  
Author(s):  
S. Sun ◽  
G. Xu
Keyword(s):  
Plasma Membrane ◽  
Sugar Transport ◽  
Cortical Cell ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizal Symbiosis ◽  
Mycorrhizal Symbiosis ◽  
Sugar Transporters ◽  
Nutrient Exchange ◽  
Am Symbiosis ◽  
Cell Interface

In arbuscular mycorrhizal (AM) symbioses, there is a reciprocal nutrient exchange, mainly sugar and phosphate, between partners. Transport of phosphate from fungus to plant has been well characterized, and this aspect of AM symbiosis has been reviewed. This mini-review is specifically devoted to sugar transport from plant to fungus in AM symbiosis and discusses the possible links between sugar transporters and AM-inducible inorganic phosphate (Pi) transporters and plasma membrane proton-ATPases in the arbuscule-cortical cell interface. Exploring the sugar transport mechanisms could further contribute to our understanding of nutrient exchange between the two symbiotic partners. Key words: Arbuscular mycorrhizal symbiosis, sugar flux, sugar transporter, phosphate transporter, plasma membrane, H+-ATPase

scholarly journals Hexose translocation mediated by SlSWEET5b is required for pollen maturation in Solanum lycopersicum

2021 ◽  
Author(s):  
Han-Yu Ko ◽  
Hsuan-Wei Tseng ◽  
Li-Hsuan Ho ◽  
Lu Wang ◽  
Tzu-Fang Chang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fusion Proteins ◽  
Invertase Activity ◽  
Flower Buds ◽  
Phloem Unloading ◽  
Pollen Maturation ◽  
Carbon Supply ◽  
Mature Flower ◽  
Molecular Nature

AbstractPollen fertility is critical for successful fertilization and, accordingly, for crop yield. While sugar unloading affects growth and development of all types of sink organs, the molecular nature for sugar import to tomato pollen is poorly understood. However, SWEET transporters have been proposed to function in pollen development. Here, qRT-PCR revealed that SlSWEET5b was markedly expressed in flowers when compared to the remaining tomato SlSWEETs; particularly, in the stamens of maturing flower buds undergoing mitosis. Distinct accumulation of SlSWEET5b-GUS fusion proteins was present in mature flower buds, especially in anther vascular and inner cells, symplasmic isolated pollen cells and styles. The demonstration that GFP fusion proteins located to the plasma membrane support the idea that the SlSWEET5b carrier functions in apoplasmic sugar translocation during pollen maturation. Such function is in line with data from yeast complementation experiments and radiotracer uptakes, showing that SlSWEET5b operates as a low affinity hexose-specific passive facilitator, with a KM of ~36 mM. Most importantly, RNAi-mediated suppression of SlSWEET5b expression resulted in shrunken nucleus-less pollen cells, impaired germination and low seed yield. Interestingly, stamens from SlSWEET5b-silenced tomato mutants contained significantly lower amounts of sucrose and increased invertase activity, pointing to reduced carbon supply and perturbed sucrose homeostasis in this tissue. Taken together, our findings reveal an essential role of SlSWEET5b in mediating apoplasmic hexose import into phloem unloading cells and into developing pollen cells to support pollen mitosis and maturation in tomato flowers.One-sentence SummaryPlasma-membrane-localized SlSWEET5b facilitates a sequential hexose flux, from phloem to anther cells and from anther locule to pollen, to support pollen maturation and fertility in tomato flowers.

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