Only five genes have been characterized in grape Vitis vinifera and sugarcane Saccharum spp. In Chinese pear Pyrus bretschneideri Rehd. However, at least five of the Chinese pear SUS genes cannot be functional, as the predicted proteins are too short to contain both the SuSy domain and the glycosyl-transferase domain. Oddly, in many of these papers, only the SUS I clade included a clear separation between eudicot and monocot species; whereas in the other clades, and the SUS II clade in particular, there was no clear separation between monocots and eudicots Chen et al.
These unique phylogenetic trees raise fundamental questions about the evolution of SuSy in plants. However, it is important to note that some of these trees were created using limited numbers of monocot or dicot species. This situation encouraged us to create a more comprehensive phylogenetic tree. We created a SuSy phylogenetic tree using SuSy amino acid sequences from 25 plant species 11 eudicots, 8 monocots, and 6 gymnosperms.
Each clade is divided into two sub-clades: monocots marked with red arcs and eudicots marked with turquoise arcs.
The SUS I clade is the largest clade, which suggests that it might be more functionally important than the other clades, leading to greater conservation of SUS genes from that clade. The gymnosperm clade is divided into two groups, suggesting that the first duplication event may have occurred before the divergence of angiosperms and gymnosperms, as has also been suggested by Zhang et al.
The separation of monocots and eudicots in these clades suggests that the duplication occurred in a common angiosperm ancestor, also reported by Zhang et al. Phylogenetic tree of SUS genes from land plants. Additional amino acid sequences were retrieved using the Plaza 3. Partial sequences and sequences with substantial deletions were excluded, leaving a total of sequences Supplementary File 1. The tree was created using the maximum-likelihood method based on the JTT matrix-based model Jones et al.
Gymnosperm species are labeled with a green arc. Turquoise arcs indicate eudicot species and red arcs indicate monocot species. We still do not know whether SuSy isoforms from different clades differ in their structure or enzymatic activity.
Arabidopsis knock-out mutants are available for all SUS genes and double mutants for clade-specific SuSy isoforms have been created.
None of those mutants exhibit any significant phenotype that suggesting redundancy between the different clades Bieniawska et al. Researchers have speculated that the main differences between the clades may be their expression patterns in different tissues and cells Bieniawska et al. Sink strength can be defined as the ability of an organ to import photoassimilates. Sink strength mainly relies on two parameters, sink organ size as a physical constraint and activity as a physiological constraint Ho, Although imported photoassimilate can be used for respiration, sink-strength estimations are mainly based on net weight gain Ho, Phloem loading is thought to be highly important for defining sink strength and the breakdown of Suc in sink organs may also contribute to sink strength.
Work with isoform-specific antibodies has revealed that specific SuSy isoforms are more abundant in the phloem. SuSy proteins have also been detected in citrus Citrus paradisi and maize phloem companion cells using immunohistological analysis Nolte and Koch, However, SuSy appear to localize to the phloem not only in the Suc unloading zones, but also in loading zones in mature leaves of citrus, maize, rice, Arabidopsis, and poplar Nolte and Koch, ; Regmi et al.
In the phloem, SuSy may play a role in the maintenance of equilibrium between Suc and its breakdown products, supplying hexoses for energy production in companion cells and substrates for complex carbohydrates, like callose Nolte and Koch, There is plenty of evidence that SuSy, and not INV, is the primary active enzyme in actively growing sink organs of different species, such as potato tubers, cassava Manihot esculenta roots, lima bean Phaseolus lunatus seeds, and tomato fruits Morrell and Rees, ; Sung et al.
Numerous studies involving plants that have altered SuSy activity and exhibit altered growth rates and weight gain in their sink organs support the putative role of SuSy in sink strength.
Pea Pisum sativum SuSy mutants rug4 also exhibited significantly reduced SuSy activity in their embryos, reduced seed weight and a wrinkled-seed phenotype Craig et al. Transgenic potato plants with reduced SuSy activity only in tubers exhibited reduced tuber dry weight Zrenner et al.
SuSy activity was also suggested as an indicator for high rice grain yield in rice breeding programs Counce and Gravois, A recent study found that the Suc-cleavage activity of a castor bean SuSy, RcSUS1, is inhibited by trehalose 6-phosphate, suggesting another mechanism by which Suc flux can be controlled in heterotrophic tissues Fedosejevs et al. Other studies have produced somewhat contradictory evidence for the role of SuSy in sink strength.
In another transgenic tomato with reduced SUS expression only in fruits, there were no reported effects on fruit development or the accumulation of starch and sugar in young green fruit, challenging the suggested importance of SuSy for sink strength Chengappa et al. In Arabidopsis, AtSUS2 and AtSUS3 mutants had altered metabolism and accumulated less transient starch during seed development, with no effect on agronomic traits like seed weight and oil content Angeles-Nunez and Tiessen, Interestingly, even a double mutant sus2 and sus3 and a quadruple mutant sus1 , sus2 , sus3 , and sus4 did not show any seed-related phenotypes Bieniawska et al.
Overall, the data suggest that SuSy might be important for sink strength, especially in starch-accumulating organs, although that role is probably not conserved in all plants. For many decades, researchers have thought that SuSy may play important roles in the conversion of Suc into starch.
The first genetic evidence for this came from the characterization of the maize sh mutant. Similarly, a pea SuSy mutant rug4 also showed reduced seed starch content Craig et al. Other studies involving transgenic plants with suppressed SUS expression have demonstrated reduced starch accumulation in potato tubers Zrenner et al. Suc can be converted into starch via different pathways, which also differ between chloroplasts and heterotrophic tissues For a comprehensive review of starch synthesis, see Bahaji et al.
Adenosine diphosphate glucose is the main molecule converted into starch by the starch synthases in plastids. In chloroplasts, the main starch-synthesis pathway starts with two molecules of triose-P produced by photosynthesis, which yield F1,6BP.
This chloroplast starch synthesis pathway does not require Suc cleavage and, therefore, cytosolic SuSy is not expected to play an important role in leaf starch synthesis. The main genetic evidence supporting this claim is that the plastidic PGI, PGM and AGPase mutants, and plants with reduced expression of these genes are either starchless or contain very low levels of starch in their leaves Bahaji et al.
However, there is also growing line of evidence suggesting that SuSy might play some role in leaf starch synthesis. Based on this and many other studies, Bahaji et al. According to this model, the rate of starch accumulation is determined by the rate of cytosolic SuSy activity that yields ADP-G, cytosolic ADP-G transport to the chloroplast, starch synthesis, starch breakdown and the efficiency of the recycling of the products of the breakdown of starch.
There is much more evidence linking SuSy to starch synthesis in non-photosynthetic tissues or sink tissues. For example, a reduction in SuSy activity reduced starch content in potato tubers, carrot taproots and maize endosperm Chourey and Nelson, ; Zrenner et al.
In addition, five maize starch-deficient endosperm mutants were screened for metabolic enzyme activity and all showed reduced SuSy activity Doehlert and Kuo, All these observations support the role of SuSy in starch accumulation. There is a lot of evidence that SUS are highly expressed in vascular tissues. SUS promoters are expressed in the vasculature of many plant species, mostly in the phloem Yang and Russell, ; Martin et al.
SuSy protein has also been immunolocalized to the phloem companion cells in citrus and maize Nolte and Koch, and in leaves of 9-day-old barley seedlings Guerin and Carbonero, SuSy is also the main enzyme metabolizing Suc in the phloem of Ricinus communis Geigenberger et al. Only a few studies have used mutant and transgenic plants to elucidate the roles of SuSy in phloem. In cucumber Cucumis sativa , transgenic plants with suppressed CsSUS3 , which is mainly expressed in root phloem companion cells, were found to be more sensitive to hypoxic stress caused by flooding Wang et al.
In contrast, the Arabidopsis double mutant of the two phloem-specific SUS sus5 sus6 exhibited no specific phenotype, even under hypoxic stress Bieniawska et al.
However, the double mutant had less callose in its sieve plates and in response to wounding, as compared with WT or quadruple-mutant sus1 , sus2 , sus3 , and sus4 plants, suggesting that AtSUS5 and AtSUS6 are essential for callose synthesis Barratt et al.
There is also sufficient evidence for the localization of SuSy to xylem tissues. Sucrose synthase activity was found in immature metaxylem and the central vessel in the elongation zone of wheat seedlings following hypoxia Albrecht and Mustroph, Relatively high mRNA levels and activity were also reported in carrot tap root xylem Sturm et al.
High SuSy activity and protein levels were reported in differentiating xylem of Robinia pseudoacacia during the spring Hauch and Magel, Sucrose synthase activity in developing xylem vessels or fibers may be particularly important for the cellulose synthesis needed for the construction of thick secondary cell walls. Work with a cell culture of Zinnia elegans revealed that SuSy is highly enriched in differentiating tracheary elements near the plasma membrane, where secondary cell-wall thickening occurs Salnikov et al.
Overexpression of SUS in several plant species increased the thickness of xylem cell walls Coleman et al. There is sufficient supporting evidence for these proposed roles from the SuSy subcellular localization to cell walls and adjacent to plasma membranes. Immunolocalization of the cotton fiber SuSy revealed an arrangement pattern similar to that of cellulose microfibril deposition Amor et al.
It was later found that a cellulose synthase rosette-like structure, isolated from azuki beans, lacks cellulose-synthesis activity in the absence of another particle referred to as the catalytic unit. Another immunolocalization study also demonstrated that cotton fiber SuSy is co-localized with callose, suggesting a dual role for SuSy in cellulose and callose synthesis Salnikov et al. Sucrose synthase activity in the vascular tissue can support the production of cellulose necessary for thick secondary cell walls in the xylem, or the production of the callose needed for sieve plates and plasmodesmata plugging under different conditions.
Evidence for a role of SuSy in callose deposition was found in an Arabidopsis double mutant of phloem-specific SUS sus5 sus6. That double mutant had less callose in its phloem plasmodesmata and in response to leaf wounding, as compared with WT or quadruple mutant sus1 , sus2 , sus3 , and sus4 plants Barratt et al.
The role of SuSy in the synthesis of cellulose and callose has been thoroughly investigated in cotton, with cotton fibers serving as a model for these processes. The development of cotton fibers starts with the initiation and elongation of the epidermal cells, followed by secondary growth and maturation marked by massive cellulose production. A fiberless cotton mutant lacking SuSy protein and activity at anthesis was identified, indicating that SuSy might be crucial for fiber initiation Ruan and Chourey, It was later shown that transgenic cotton plants with SUS suppression exhibit reduced fiber initiation and elongation Ruan et al.
In the secondary growth phase of cotton fibers, cellulose synthesis can increase fold relative to the elongation phase Delmer, and this process probably involves SusC and SusA Brill et al. It would be very interesting to see whether the proposed roles of the cell wall SuSy in cellulose and callose synthesis could be observed in transgenic cotton plants with SusC suppression or overexpression.
Different reports also support the roles of SuSy in cellulose synthesis in other plant species. Although overexpression of cotton SUS in tobacco plants did not affect cellulose content Coleman et al. Similarly, overexpression of poplar xylem SUS in tobacco plants also resulted in increased cellulose content and xylem cell-wall thickness Wei et al.
Oxygen deficiency hypoxia and a complete absence of oxygen anoxia are forms of serious abiotic stress that often cause reduced plant growth and productivity. Low-oxygen stress in plants is often caused by flooding, but may also occur naturally in dense, bulky and inner organs and tissues or in very rapidly growing tissues in which oxygen consumption is high. Oxygen is the final acceptor in the mitochondrial electron transport chain and the absence of oxygen blocks electron transfer and cellular ATP production.
One of the enzymes thought to be involved in plant responses to hypoxia is SuSy. Transcript levels of some SUS genes have been found to increase in response to low levels of oxygen in potato Biemelt et al. Oxygen deficiency has also been shown to increase SuSy protein levels in Arabidopsis roots Bieniawska et al. Increased SuSy activity under low-oxygen conditions has been noted in many plants and is often seen in combination with reduced INV activity in rice seedlings Guglielminetti et al.
The possible role of SuSy in metabolism under reduced-oxygen conditions is further supported by the findings of studies with SUS mutants and transgenic plants. Potato tubers of a SUS antisense transgenic line were more sensitive to hypoxia than control plants Biemelt et al.
A study of potato tubers of transgenic plants overexpressing INV or Suc pyrophosphorylase, which allows a way to bypass the degradation of Suc by SuSy, revealed a steeper reduction in oxygen levels inside the tubers, reduced starch synthesis and a lower ATP to ADP ratio, underscoring the importance of SuSy under low-oxygen conditions Bologa et al.
In Arabidopsis, a double-knockout mutant sus1 and sus4 was found to be more sensitive to flooding than the control Bieniawska et al. In cucumber, antisense suppression of CsSUS3 led to increased sensitivity to hypoxic stress Wang et al.
SuSy activity has also been found to be correlated with rice coleoptile length under submerged conditions, further indicating the advantage of Suc metabolism that involves SuSy under anoxic conditions Fukuda et al.
Overall, the data show that some SuSy isoforms may indeed play a vital role in metabolism under low-oxygen conditions. Sucrose synthase may play another, less studied role in the development of shoot apical meristem SAM. RNAseq data obtained by Park et al. The SlSUS4 transcript was shown to be present asymmetrically and localized to the primordia from very early stages of development using in situ hybridization with an SlSUS4 antisense probe Pien et al.
In situ hybridization also revealed the presence of SUS transcript in young maize leaf primordia, suggesting a role for SuSy in early leaf development Hanggi and Fleming, Other work involving transgenic plants that overexpress SUS genes has revealed altered growth rates that may suggest some possible effects of these genes on SAM function.
Overexpression of potato SUS in cotton plants led to increased vegetative growth Xu et al. Similarly, overexpression of aspen Popolus tremuloides SUS in Arabidopsis resulted in an increased growth rate and increased plant biomass, and also induced early flowering Xu and Joshi, Overexpression of cotton SUS in tobacco also led to an increased growth rate and taller plants Coleman et al. Although the mechanism by which SUS overexpression speeds up the growth rate is not clear, it is tempting to speculate that increased SuSy activity in the meristem may facilitate increased cell proliferation.
The transgenic plants overexpressing AtSUS1 showed increased chlorophyll levels, as well as increased photosynthesis, TSS total soluble sugars , starch, Suc and Fru, as well as increased enzymatic activity of SPS and SPP in leaves, indicating increased sugar production in the transgenic plants.
In addition to serving as energy resources and structural components, sugars such as Suc, Glc, and Fru may also act as signaling molecules to regulate developmental processes and responses to environmental changes Sheen et al. These sugars have also been shown to rapidly affect the expression of many genes, even at concentrations as low as 1 mM Kunz et al.
The role of sugars as signaling molecules in the SAM is a subject of lively debate and it is not always easy to differentiate between their signaling function and their metabolic role. In work with Arabidopsis seedlings conducted by Pfeiffer et al. Those authors also found that a non-metabolizable Suc analog, palatinose, has no effect on WUS expression in the dark, possibly indicating that Suc per se does not act as a signaling molecule in the SAM during seedling establishment.
Other studies have found correlations between Suc treatments or levels and flowering, suggesting that Suc may play a signaling role in the development of SAM into flowers reviewed by Cho et al. The Suc signal for flowering may be mediated by trehalose 6-phosphate T6P.
Another reason to believe that Suc and SuSy may play some regulatory function rather than just a metabolic one comes from tomato plants in which the expression of three SUS genes was suppressed Goren et al. These plants exhibited abnormal leaf development and irregular auxin patterning, suggesting that altered sugar signaling in the SAM or primordia, rather than lower sugar metabolism, is likely to be the cause of these developmental changes.
Sucrose synthase may also play other important roles, in addition to its role in Suc cleavage. The localization of SuSy to mitochondria and its possible interaction with a high voltage-dependent anion channel suggest that these SuSy may play a role in regulating solute fluxes between the mitochondria and the cytosol Subbaiah et al.
Plant SuSy have also been found to play a role in mutualism with symbiotic organisms like Rhizobium bacteria. Those plants were incapable of effective nitrogen fixation, even though the nodules appeared normal Gordon et al. Although nitrogenase protein levels were normal, there was no nitrogenase activity. It was suggested that Susy activity might be essential for nitrogen fixation in root nodules, due to the low-oxygen environment in the nodules Gordon et al.
Sucrose synthase may also play a role in metabolism under heat stress. A recent study found that a SUS3 allele that is highly expressed during seed ripening may confer resistance to the chalky grain phenotype of brown rice caused by heat stress Takehara et al. The expression of the SUS3 gene was found to be higher in the resistant line under heat stress.
Interestingly, transgenic plants of a commercial rice cultivar expressing SUS3 showed a decreased percentage of chalky grains under heat stress only when both the promoter and the cDNA of the heat-tolerant allele were introduced, indicating not only the importance of the SUS3 protein, but also the response rate to heat stress in terms of gene expression Takehara et al.
Another potential heat-tolerant SuSy was purified from a heat-tolerant line of wheat WH In strawberry Fragaria ananassa , SuSy may play an important role in fruit ripening. Strawberry fruits with RNAi suppression of FaSUS1 by virus-induced gene-silencing exhibited delayed fruit ripening, maintained their firmness and exhibited delayed anthocyanin accumulation Zhao et al.
To summarize, plant SuSy activity has been shown to play important roles in plant sugar metabolism, primarily in sink tissues. Plant SuSy proteins are found primarily in the cytosol or adjacent to the plasma membrane, although some SuSy isoforms are found in cell walls, mitochondria or vacuoles, or are bound to actin.
Plant SuSy enzymes have been shown to be involved in several different metabolic pathways, such as those for starch, callose and cellulose synthesis, and to play developmental and possibly signaling roles in sink carbohydrate flux, vascular tissues and meristem functioning. One possibility is suggested by their differential subcellular locations.
The SuSy in plasma membranes and cell walls and their production of UDP-G may be important for directing carbon toward cellulose or callose synthesis; whereas INV may direct carbon to other metabolic pathways. Sucrose synthase SuSy is a glycosyl transferase enzyme that plays a key role in sugar metabolism, primarily in sink tissues. The products of sucrose cleavage by SuSy are available for many metabolic pathways, such as energy production, primary-metabolite production, and the synthesis of complex carbohydrates.
SuSy proteins are usually homotetramers with an average monomeric molecular weight of about 90 kD about amino acids long. Plant SuSy isozymes are mainly located in the cytosol or adjacent to plasma membrane, but some SuSy proteins are found in the cell wall, vacuoles, and mitochondria. It was suggested that Susy activity might be essential for nitrogen fixation in root nodules, due to the low-oxygen environment in the nodules Gordon et al.
Sucrose synthase may also play a role in metabolism under heat stress. A recent study found that a SUS3 allele that is highly expressed during seed ripening may confer resistance to the chalky grain phenotype of brown rice caused by heat stress Takehara et al.
The expression of the SUS3 gene was found to be higher in the resistant line under heat stress. Interestingly, transgenic plants of a commercial rice cultivar expressing SUS3 showed a decreased percentage of chalky grains under heat stress only when both the promoter and the cDNA of the heat-tolerant allele were introduced, indicating not only the importance of the SUS3 protein, but also the response rate to heat stress in terms of gene expression Takehara et al.
Another potential heat-tolerant SuSy was purified from a heat-tolerant line of wheat WH In strawberry Fragaria ananassa , SuSy may play an important role in fruit ripening. Strawberry fruits with RNAi suppression of FaSUS1 by virus-induced gene-silencing exhibited delayed fruit ripening, maintained their firmness and exhibited delayed anthocyanin accumulation Zhao et al.
To summarize, plant SuSy activity has been shown to play important roles in plant sugar metabolism, primarily in sink tissues. Plant SuSy proteins are found primarily in the cytosol or adjacent to the plasma membrane, although some SuSy isoforms are found in cell walls, mitochondria or vacuoles, or are bound to actin.
Plant SuSy enzymes have been shown to be involved in several different metabolic pathways, such as those for starch, callose and cellulose synthesis, and to play developmental and possibly signaling roles in sink carbohydrate flux, vascular tissues and meristem functioning.
One possibility is suggested by their differential subcellular locations. The SuSy in plasma membranes and cell walls and their production of UDP-G may be important for directing carbon toward cellulose or callose synthesis; whereas INV may direct carbon to other metabolic pathways. SuSy activity is feedback-inhibited by its product, Fru, and its activity is also reversible.
These features of SuSy may help to control the amount of Suc consumed in different organs, for example, in stems and petioles. Only controlled amounts of the transported Suc must be cleaved and metabolized to support the maintenance and development of vascular and other supporting tissues.
It is likely that feedback inhibition of SuSy activity and substrate inhibition of fructokinase by Fru Schaffer and Petreikov, ; Kanayama et al. That is, in case of excess cleavage of Suc by SuSy, the increased fructose Fru inhibits fructokinase activity so that fructose accumulates and that accumulated Fru inhibits further cleavage of Suc by SuSy.
Although plant SuSy proteins have been the subject of intensive study, we are still faced with major gaps in our understanding of the functions of these enzymes.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Abdullah, M. The sucrose synthase gene family in Chinese pear Pyrus bretschneideri Rehd.
Molecules 23, 1— Albrecht, G. Localization of sucrose synthase in wheat roots: increased in situ activity of sucrose synthase correlates with cell wall thickening by cellulose deposition under hypoxia. Planta , — PubMed Abstract Google Scholar. Amor, Y. A membrane-associated form of sucrose synthase and its potential role in synthesis of cellulose and callose in plants. An, X. Identification and characterization of the Populus sucrose synthase gene family.
Gene , 58— Angeles-Nunez, J. Study of AtSUS2 localization in seeds reveals a strong association with plastids. Plant Cell Physiol. Arabidopsis sucrose synthase 2 and 3 modulate metabolic homeostasis and direct carbon towards starch synthesis in developing seeds. Azama, K. Lysine-containing proteins in maize endosperm: a major contribution from cytoskeleton-associated carbohydrate-metabolizing enzymes.
Bahaji, A. PLoS One 9:e Starch biosynthesis, its regulation and biotechnological approaches to improve crop yields. Arabidopsis thaliana mutants lacking ADP-glucose pyrophosphorylase accumulate starch and wild-type ADP-glucose content: further evidence for the occurrence of important sources, other than ADP-glucose pyrophosphorylase, of ADP-glucose linked to leaf starch biosynthesis. Bailey-Serres, J. Genetic and molecular approaches to the study of the anaerobic response and tissue specific gene expression in maize.
Plant Cell Environ. Baroja-Fernandez, E. Enhancing sucrose synthase activity in transgenic potato Solanum tuberosum L. Sucrose synthase catalyzes the de novo production of ADPglucose linked to starch biosynthesis in heterotrophic tissues of plants. Most of ADP x glucose linked to starch biosynthesis occurs outside the chloroplast in source leaves.
Barratt, P. Normal growth of Arabidopsis requires cytosolic invertase but not sucrose synthase. Baud, S. Structure and expression profile of the sucrose synthase multigene family in Arabidopsis.
Biemelt, S. Sucrose synthase activity does not restrict glycolysis in roots of transgenic potato plants under hypoxic conditions. Planta , 41— Bieniawska, Z. Analysis of the sucrose synthase gene family in Arabidopsis. Plant J. Bologa, K. A bypass of sucrose synthase leads to low internal oxygen and impaired metabolic performance in growing potato tubers. Plant Physiol. Brill, E. A novel isoform of sucrose synthase is targeted to the cell wall during secondary cell wall synthesis in cotton fiber.
Buckeridge, M. Evidence for multiple sites of glucosyl transfer in the synthase complex. Cai, G. Distribution of callose synthase, cellulose synthase, and sucrose synthase in tobacco pollen tube is controlled in dissimilar ways by actin filaments and microtubules. Carlson, S. Evidence for plasma membrane-associated forms of sucrose synthase in maize. Chen, A. Analyses of the sucrose synthase gene family in cotton: structure, phylogeny and expression patterns. BMC Plant Biol.
Chengappa, S. Transgenic tomato plants with decreased sucrose synthase are unaltered in starch and sugar accumulation in the fruit. Plant Mol. Cho, L. Roles of sugars in controlling flowering time. Plant Biol. Chopra, S. Sucrose synthase of Arabidopsis : genomic cloning and sequence characterization. Chourey, P. The enzymatic deficiency conditioned by the shrunken-1 mutations of maize.
Ciereszko, I. Glucose and mannose regulate the expression of a major sucrose synthase gene in Arabidopsis via hexokinase-dependent mechanisms. Coleman, H. Up-regulation of sucrose synthase and UDP-glucose pyrophosphorylase impacts plant growth and metabolism. Plant Biotechnol. Sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure.
Counce, P. Sucrose synthase activity as a potential indicator of high rice grain yield. Crop Sci. Craig, J. Mutations at the rug4 locus alter the carbon and nitrogen metabolism of pea plants through an effect on sucrose synthase. Antisense inhibition of tomato fruit sucrose synthase decreases fruit setting and the sucrose unloading capacity of young fruit.
Plant Cell 11, — Dejardin, A. Delmer, D. Google Scholar. Doehlert, D. Sugar metabolism in developing kernels of starch-deficient endosperm mutants of maize. Duncan, K. The three maize sucrose synthase isoforms differ in distribution, localization, and phosphorylation.
Etxeberria, E. Evidence for a tonoplast-associated form of sucrose synthase and its potential involvement in sucrose mobilization from the vacuole. Eveland, A. Sugars, signalling, and plant development. Fedosejevs, E. The signal metabolite trehalosephosphate inhibits the sucrolytic activity of sucrose synthase from developing castor beans.
FEBS Lett. Biochemical and molecular characterization of RcSUS1, a cytosolic sucrose synthase phosphorylated in vivo at serine 11 in developing castor oil seeds. Fu, H. Sink- and vascular-associated sucrose synthase functions are encoded by different gene classes in potato. Plant Cell 7, — Fujii, S. Sucrose synthase is an integral component of the cellulose synthesis machinery.
Fukao, T. Plant responses to hypoxia - is survival a balancing act? Trends Plant Sci. Fukuda, A. Rice cultivars with higher sucrose synthase activity develop longer coleoptiles under submerged conditions. Plant Prod. Geigenberger, P. Sucrose is metabolised by sucrose synthase and glycolysis within the phloem complex of Ricinus communis L. Gerber, L. Deficient sucrose synthase activity in developing wood does not specifically affect cellulose biosynthesis, but causes an overall decrease in cell wall polymers.
New Phytol. German, M. Suppression of fructokinase encoded by LeFRK2 in tomato stem inhibits growth and causes wilting of young leaves. Gordon, A. Sucrose synthase in legume nodules is essential for nitrogen fixation. Goren, S. Comparison of a novel tomato sucrose synthase, SlSUS4, with previously described SlSUS isoforms reveals distinct sequence features and differential expression patterns in association with stem maturation.
Suppression of sucrose synthase affects auxin signaling and leaf morphology in tomato. PLoS One e Guerin, J. The spatial distribution of sucrose synthase isozymes in barley. Guglielminetti, L. Effect of anoxia on carbohydrate-metabolism in rice seedlings. Haigler, C. Carbon partitioning to cellulose synthesis. Hanggi, E. Sucrose synthase expression pattern in young maize leaves: implications for phloem transport.
Harada, T. Induction of sucrose synthase and its roles during anaerobic growth in pondweed turions. Expression of sucrose synthase genes involved in enhanced elongation of pondweed Potamogeton distinctus turions under anoxia. Hardin, S. Phosphorylation of sucrose synthase at serine occurrence and possible role as a signal for proteolysis. Hauch, S. Extractable activities and protein content of sucrose-phosphate synthase, sucrose synthase and neutral invertase in trunk tissues of Robinia pseudoacacia L.
Hesse, H. Expression analysis of a sucrose synthase gene from sugar beet Beta vulgaris L. Hirose, T. An expression analysis profile for the entire sucrose synthase gene family in rice. Plant Sci. Ho, L. Metabolism and compartmentation of imported sugars in sink organs in relation to sink strength.
Huang, D. Purification and characterization of sucrose synthase isozymes from etiolated rice seedlings. Huang, Y. Molecular cloning and expression analysis of seven sucrose synthase genes in bamboo Bambusa emeiensis : investigation of possible roles in the regulation of cellulose biosynthesis and response to hormones. New insight into the catalytic properties of rice sucrose synthase. Jones, D. The rapid generation of mutation data matrices from protein sequences.
Bioinformatics 8, — Kanayama, Y. Tomato fructokinases exhibit differential expression and substrate regulation. Keller, F. Sucrose synthase, a cytosolic enzyme in protoplasts of Jerusalem artichoke tubers Helianthus tuberosus L.
Kleines, M. Isolation and expression analysis of two stress-responsive sucrose-synthase genes from the resurrection plant Craterostigma plantagineum Hochst. Planta , 13— Klotz, K.
Wounding, anoxia and cold induce sugarbeet sucrose synthase transcriptional changes that are unrelated to protein expression and activity. Komina, O.
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