Sucrose Phosphate Synthetase Activity Research Articles

The interaction between CmPIF8 and CmACO1 under postharvest red light treatment might affect fruit ripening and sucrose accumulation in oriental melon fruit

Light and plant hormones are involved in regulating the growth, development and fruit quality formation. However, it remains unclear whether light regulates the fruit quality of oriental melon by affecting hormones. Sucrose is mainly accumulated in mature oriental melon fruit, and the accumulation of sucrose is closely related to ethylene. Here, the climacteric melon fruit ‘HS’ were treated with red and blue light at ethylene release initial stage (30 d after anthesis, DAA), and the results showed that the red light treatment enhanced the production of ethylene and the activity of 1-aminocyclopropane-1-carboxylate oxidase (ACO), as well as CmACO1 expression in melon fruit at postharvest stage. Red light also up-regulated the sucrose accumulation and the activity of sucrose phosphate synthetase (SPS) and CmSPS1 expression in postharvest melon fruit. Moreover, we found that PHYTOCHROME INTERACTING FACTOR 8 (PIF8), as a negative regulator of ethylene biosynthesis by directly binding to CmACO1 promoter. In summary, red light treatment at postharvest stage suppressed the expression of CmPIF8, and released the inhibitory effect of CmPIF8 on CmACO1, thereby promoting the ethylene production and fruit ripening, which indirectly increased the sucrose content in melon fruit.

Split nitrogen fertilizer application\xa0improved grain yield in winter wheat (Triticum aestivum L.) via modulating antioxidant capacity and 13C photosynthate mobilization under water-saving irrigation conditions

A water-saving cultivation technique of supplementary irrigation based on soil moisture levels has been adopted for winter wheat production in the Huang-Huai-Hai Plain of China, due to the enhanced water-use efficiency. However, appropriate split nitrogen management may further improve crop growth and grain yield. Here, we conducted a 2-year field experiment to determine if split nitrogen management might improve wheat productivity by enhancing 13C photosynthate mobilization and the antioxidant defense system under water-saving conditions. Split nitrogen management involved a constant total nitrogen rate (240 kg ha−1) split in four different proportions between sowing and jointing stage, i.e., 10:0 (N1), 7:3 (N2), 5:5 (N3), and 3:7 (N4). The N3 treatment significantly enhanced “soil-plant analysis development” values, superoxide dismutase antioxidant activity, soluble protein content, sucrose content, and sucrose phosphate synthetase activity, although it reduced the accumulation of malondialdehyde (MDA). The N3 treatment ultimately increased the amount of dry matter assimilation after anthesis significantly. In addition, the 13C isotope tracer experiment revealed that the N3 treatment promoted the assimilation of carbohydrates after anthesis and their partitioning to the developing grains. Compared to the unequal ratio treatments (N1, N2, and N4), the equal ratio treatment (N3) increased grain yield by 5.70–16.72% via increasing 1000-grain weight and number of grains per spike in both growing seasons. Therefore, we recommend the use of a 5:5 basal-topdressing split nitrogen fertilizer application under water-saving irrigation conditions to promote antioxidant enzyme activity and the remobilization of photosynthate after anthesis for improving wheat grain yield.

Sucrose phosphate synthase plays a key role in boron‐promoted sucrose synthesis in tobacco leaves

AbstractBoron (B) is essential for plant growth. The mechanism of B interacting with sucrose transport is not fully understood. In detached tobacco leaves treated with increasing B concentrations, the concentrations of sucrose, glucose, fructose, and starch as well as the activities of sucrose phosphate synthetase (SPS), sucrose synthetase (SS), and α‐amylase were quantified. In addition, the expression levels of sucrose transporters (SUT1 and SUT4) were determined. The data presented here suggest that B promotes the sucrose concentration and transport via elevation of SPS activity, decrease of SS activity, and increase of SUT4 expression level.

Effects of Key Enzyme Activities in Sucrose Metabolism on Fiber Quality in High Quality Upland Cotton

Fiber strength is an important index that measures the fiber quality, which determined by cellulose deposition characteristics. Cellulose synthesis and accumulation are affected by many enzymes including sucrose synthetase (SS), sucrose phosphate synthetase (SPS) and so on. Up to date, there have been few reports about cellulose accumulation and key enzymes relating to sucrose metabolism in high quality upland cotton cultivars. To investigate the relationship between fiber quality differences and relating sucrose metabolism enzymes, a filed experiment was conducted at Shandong Agricultural University in 2006–2007. Three upland cotton cultivars including Ludimianlu 324 and Yumian1(YM-1) (high quality) and Lumianyan (18) (common quality) were used in the experiment. Leaves were sampled at 15, 30, 45, and 60 days after leaf unfolding. Flowers were labeled at anthesis and sampled every 7 days from 7 days after anthesis. The result showed that the sucrose content was higher with higher SPS activities in high quality upland cotton leaves. The simulation with Logistic equation of cotton cellulose accumulation showed that the accumulation duration was longer and the accumulation rate was moderate, so the final cellulose content was higher in high quality upland cotton cultivar. Compared with common upland cotton, the sucrose content was higher in fiber at early growth stage in high quality upland cotton, which supplied enough original substrate for secondary wall thickening. Meanwhile, the SS activity was higher and consistent with cellulose accumulation duration in high quality upland cotton. Furthermore, high quality upland cotton had higher SPS activity before termination of cellulose accumulation duration. It was suggested that SPS activity in leaves, SS and SPS activities in fibers had close correlation with cellulose accumulation and fiber quality.

Carbohydrate Metabolism in Leaf Blades and Stems of Rice Cultivar Akitakomachi at the Ripening Stage.

水稲あきたこまちを圃場で栽培し, 出穂前に葉身摘除処理, 出穂直後に穂の部分摘除処理を行い, 登熟期におけるソース・シンク関係の変化が出穂前に蓄積した炭水化物の転流や出穂後の光合成産物の蓄積・転流に及ぼす影響について検討した. 水稲葉身では,デンプンの蓄積が極めて小さく, 炭水化物含有率が大きくなるほどショ糖の占める比率が大きくなった. 茎 (葉鞘を含む) においても基本的には同様の傾向がみられたが, デンプンの蓄積も著しかった. 穂重が急激に増加する登熟初期には, 葉身, 茎とも炭水化物, とくに, ショ糖の含有率が低下したが, 茎での低下が一層著しかった. この時期は, シンク能が非常に高く, 貯蔵炭水化物や新生光合成産物によるソースの供給能力が, 登熟歩合や子実収量を決定する重要要因と考えられた. また, 穂重の増加が緩やかになる登熟中期から後期にかけては, 穂への転流が停滞し光合成産物のソース器宮での再蓄積が観察された. とくに, 転流型のショ糖の蓄積が非常に大きいことから, この時期には, ソース能よりもシンク能の大きさや活性が, 光合成産物の転流を制限していると考えられた. 葉身におけるショ糖の転流・蓄積と関係の深いショ糖リン酸合成酵素の登熟期止葉における活性は, 葉身の老化とほぼ平行して低下した.

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

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.

Role of Invertase in Sugar Content in Highbush Blueberries ( Vaccinium corymbosum, L.)

Six batches of ripe blueberries (Vaccinium corymbosum L.) were analysed for sugar content. Glucose and fructose were found to be the predominant sugars, and were present in approximately equal proportion (glucose:fructose ratio of about 1). Distinct differences were observed between the sucrose concentrations of all batches; the proportion of sucrose present ranged between 1.6 and 14.6 g per 100 g of total sugar. No sucrose synthetase and sucrose phosphate synthetase activity was detected in any of the batches, but each batch exhibited an invertase activity. This appeared to be inversely proportional to sucrose concentration. Variations in sucrose concentration were attributed to the action of the enzyme, and invertase activity was closely correlated with sucrose content. The optimum temperature for this enzyme was 60°C. Invertase can modify the sugar profile and affect the flavour of end products. Temperature control is suggested as a method to inactivate invertase, to prevent all modifications.

Control of carbon partitioning by light quality mediated by phytochrome

Dry matter distribution, soluble sugar and leaf starch contents, and sucrose phosphate synthetase (SPS) and acid invertase levels were measured in organs of radish ( Raphanus sativus L.) plants which had been grown in either white light (WL) or white light plus far-red light (WL + FR). Plants which received additional FR accumulated significantly less dry matter and distributed a greater proportion of this into aerial growth than did controls under WL only. Leaves from plants treated with WL + FR contained 2–3 times as much hexose sugar, lower starch levels and significantly higher SPS activity than plants grown under WL only. The petioles of plants grown in WL + FR contained double the amount of hexose sugar and significantly higher levels of acid invertase activity than those of WL-grown plants. Conversely, the roots of WL + FR plants contained less hexoses and had lower acid invertase activity than WL-grown plants. The results indicate a close relationship between changes in plant growth and morphology in response to altered light quality, mediated via the photoreceptor, phytochrome, and altered enzyme activity in both source and sink organs.

Light-induced Increase in Sucrose Phosphate Synthetase Activity in Leaves of Lolium temulentum

Mature leaves of Lolium temulentum L. were assayed for sucrose phosphate synthetase activity at different times during the photoperiod. There was a rapid increase in activity at the onset of illumination which was not observed in leaves maintained in darkness. The activity prior to illumination was insufficient to catalyse the rates of sucrose synthesis observed in illuminated detached leaves; after 15 min illumination the two processes were of similar magnitude.

Untersuchungen über den Zusammenhang zwischen der Aktivität der Saccharose-6-Phosphat-Synthetase und den Nettophotosyntheseraten sowie den Saccharose- und Stärkegehalten der Blätter von Solatium melongena L.

Summary Growing fruit strongly influenced sucrose-phosphate synthetase (UDP-glucose: D-fructose-6-phosphate 2-glucosyltransferase EC 2.4.1.14) activity, net photosynthetic rates, and sucrose and starch content of leaves of eggplants ( Solatium melongena L.). On the contrary flowers and mature fruit did not influence assimilate production or enzyme activity. Removal of growing fruit caused a decrease of sucrose-phosphate synthetase activity and net photosynthetic rates. The sucrose concentration in leaves increased but decreased again some days after fruit was removed. On the other hand starch content remained above values measured in leaves of plants bearing fruit. The role of sucrose phosphate synthetase in source-sink relationship is discussed.

The effect of sucrose on the rate of de novo sucrose biosynthesis in leaf protoplasts from spinach wheat and barley

Protoplasts from the leaves of wheat, spinach, and barley were found to synthesize [ 14C]sucrose from 14CO 2 at rates comparable with those of the parent tissue. CO 2 fixation and sucrose biosynthesis ceased virtually immediately when the light was switched off. The effect of sucrose pretreatment on the rate of de novo sucrose biosynthesis was found to vary with leaf age and with plant species. Protoplasts from young wheat and spinach leaves showed an apparent stimulation of the rate of sucrose biosynthesis after sucrose pretreatment. In protoplasts from mature leaves of spinach, sucrose pretreatment produced inhibition. After sucrose pretreatment protoplasts from mature spinach leaves showed low rates of CO 2 fixation, and sucrose biosynthesis compared with controls. Conversely, with protoplasts from mature leaves of wheat and barley, the rate of CO 2 fixation was unchanged and there was little or no effect on the rate of sucrose biosynthesis after sucrose pretreatment. Preincubation with sucrose had no effect on the activity of sucrose-phosphate synthetase (EC 2.4.1.14), cytoplasmic fructose-1,6-bisphosphatase (EC 3.1.3.11), or UDPglucose pyrophosphorylase (EC 2.7.7.9) from spinach leaves. It was concluded that there is no direct feedback inhibition of sucrose on the sucrose biosynthetic pathway in leaves of spinach, wheat, and barley. The mechanism of inhibition of sucrose biosynthesis by sucrose in spinach remains to be elucidated.

Biochemical Basis for Partitioning of Photosynthetically Fixed Carbon between Starch and Sucrose in Soybean (Glycine max Merr.) Leaves

The control of photosynthetic starch/sucrose formation in leaves of soybean (Glycine max L. Merr.) cultivars was studied in relation to stage of plant development, photosynthetic photoperiod, and nitrogen source. At each sampling, leaf tissue was analyzed for starch content, activities of sucrose-metabolizing enzymes, and labeling of starch and sucrose (by (14)CO(2) assimilation) in isolated cells. In three of the four varieties tested, nodulated plants had lower leaf starch levels and higher activities of sucrose phosphate synthetase (SPS), and isolated mesophyll cells incorporated more carbon (percentage of total (14)CO(2) fixed) into sucrose and less into starch as compared to nonnodulated (nitrate-dependent) plants. The variation among cultivars and nitrogen treatments observed in the activity of SPS in leaf extracts was positively correlated with labeling of sucrose in isolated cells (r = 0.81) and negatively correlated with whole leaf starch content (r = -0.66). The results suggested that increased demand for assimilates by nodulated roots may be accommodated by greater partitioning of carbon into sucrose in the mesophyll cells. We have also confirmed the earlier report (Chatterton, Silvius 1979 Plant Physiol 64: 749-753) that photoperiod affects partitioning of fixed carbon into starch. Within two days of transfer of nodulated soybean Ransom plants from a 14-hour to a 7-hour photoperiod, leaf starch accumulation rates doubled, and this effect was associated with increased labeling of starch and decreased labeling of sucrose in isolated cells. Concurrently, activities of SPS, sucrose synthase, and uridine diphosphatase in leaves were decreased.Four nodulated soybean cultivars were grown to maturity in a greenhouse. Fully expanded leaves at the top of the canopy were sampled during vegetative growth (45 days), at flowering (79 days), and at mid-podfill (120 days). In general, activities of SPS and uridine-5'-diphosphatase were highest during vegetative growth, and they decreased during reproductive development, whereas activity of sucrose synthase and leaf starch content tended to increase. Leaf starch was negatively correlated with levels of SPS (r = -0.71). The results support the postulate that sucrose-P synthetase is a key control point regulating the photosynthetic formation of sucrose, and, hence, starch.

Diurnal, seasonal, and genotypic variation of sucrose phosphate synthetase from maize leaf blades

Sucrose phosphate synthetase (SPS) activity of leaf blades from seven inbred lines of maize ( Zea mays L.) was monitored throughout the growing season. Activity was low during the first part of the season, steadily increased until tassel emergence, and then declined. Some genotypes showed a second minor peak of SPS activity during ear fill. Differences among the genotypes were most apparent near tasselling. During a 24-h period, peaks in SPS activity were observed at approx. 1600 and 0200 hours. The possibility that SPS, glucose-6-phosphate dehydrogenase (G-6-PDH), and phosphofructokinase (PFK) may compete for hexose-phosphates in discussed.

Changes in the activity of sucrose-synthesizing enzymes in developing leaves of Lolium temulentum

Sucrose phosphate synthetase was assayed throughout the development of the fourth leaf of Lolium temulentum L. Activity was maximal at the time of ligule formation and subsequently declined. Specific sucrose phosphate phosphatase was always present in excess although sucrose synthetase activity was considerably lower and remained unchanged. Maximum levels of sucrose phosphate synthetase activity are comparable in magnitude to levels of photosynthetic activity in mature grass leaves and with estimates of sucrose transport from the flag leaf into developing grass seeds.

Sucrose absorption and synthesis by excised Lycopersicon esculentum roots

Asymmetrically-labelled sucrose was absorbed intact by excised roots of tomato, grown in sucrose. Glucose-grown roots possessed sucrose synthetase and sucrose phosphate synthetase activity.

Carbohydrate metabolism in Musa paradisiaca

Considerable variations exist in the content of glucose, fructose, sucrose, starch and protein and in the activities of enzymes involved in carbohydrate metabolism between different parts of the banana plant ( Musa paradisiaca). Sucrose synthetase is present in the highest concentration in rootstock and fruit pulp, and sucrose phosphate synthetase in the pseudostem. The highest ratio of the activity of sucrose phosphate synthetase to sucrose synthetase is found in leaves. Acid invertase is present in leaves, leaf-sheath and fruit pulp and is not demonstrable in rootstock and pseudostem. Neutral invertase activity is high in pseudostem and leaf-sheath. Starch phosphorylase is largely concentrated in fruit pulp and rootstock. The maximum activity of ATP: d-phosphoglucose (ADPG) pyrophosphorylase is found in rootstock. β-Amylase is not demonstrable in rootstock and is largely concentrated in leaf-sheath. Hexokinase is most active in rootstock and the lowest in leaves. Acid phosphatase and alkaline phosphatase activity is highest in fruit pulp and pseudostem. Glucosephosphate isomerase is most active in the rootstock and lowest in the leaves.

The activity of uridine diphosphate glucose–d-fructose 6-phosphate 2-glucosyltransferase in leaves

1. By using EDTA in reaction mixtures it was possible to determine the activity of sucrose phosphate synthetase in freshly prepared leaf extracts without the complications caused by sucrose phosphatase. 2. EDTA was found also to increase the activity of sucrose phosphate synthetase by as much as 100%. 3. High sucrose phosphate synthetase activities were found in leaf preparations in which sucrose phosphatase was inhibited by EDTA. By contrast with previous reports, the activities were sufficient to allow sucrose synthesis in leaves during photosynthesis to occur via sucrose phosphate. 4. Sugar-cane plants having different rates of photosynthesis also had different activities of sucrose phosphate synthetase in their leaves. 5. It is suggested that the activity of sucrose phosphate synthetase in leaves may play a role in the control of the rate of photosynthesis.