scholarly journals CHANGES IN CARBOHYDRATE LEVELS AND SUCROSE-METABOLYZING ENZYMES DURING DEVELOPING AND RIPENING IN WATERMELON

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 754f-755 ◽  
Author(s):  
F.M. Woods ◽  
D.G. Himelrick ◽  
R. Aynaou ◽  
G.E. Boyhan ◽  
T.M. Brasher
Keyword(s):  
Sucrose Synthase ◽  
Temporal Pattern ◽  
Reducing Sugars ◽  
Citrullus Lanatus ◽  
Soluble Sugars ◽  
Sucrose Phosphate Synthase ◽  
Metabolizing Enzymes ◽  
Sucrose Metabolizing Enzymes ◽  
Carbohydrate Levels ◽  
Sucrose Phosphate

Changes in the activities of sucrose-metabolizing enzymes as related to ontogeny and ripening were studied in fruit mesocarp tissues of watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai, cvs. A.U. Producer and Sweet Scarlet]. The levels of soluble sugars and the activities of sucrose synthase (SS; EC 2.4.1.13), sucrose-phosphate synthase (SPS; EC 2.4.1.14), and invertase (INV; EC 3.2.1.26) were measured. The temporal pattern of these enzymes relative to the levels of soluble sugars were similar for both cultivars. `Sweet Scarlet' was characterized by having higher INV and SPS activities, while SS activities tended to be similar in both cultivars during fruit development. During later stages of ripening, `Sweet Scarlet' tended toaccumulate reducing sugars, while `AU Producer' tended to accumulate sucrose and therefore had lower sucrose-cleaving enzyme activity. Results indicate that SPS and INV appear to play a prominent role in carbohydrate metabolism in developing and ripening tissues of watermelon.

Non-Structural Carbohydrates and Catalytic Activities of Sucrose Metabolizing Enzymes in Trunks of Two Juglans Species and their Role in Heartwood Formation

Holzforschung ◽  
2001 ◽  
Vol 55 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Elisabeth Magel ◽  
Amani Abdel-Latif ◽  
Rüdiger Hampp
Keyword(s):  
Sucrose Synthase ◽  
Soluble Sugars ◽  
Late Summer ◽  
Sucrose Phosphate Synthase ◽  
Black Walnut ◽  
Early Winter ◽  
Heartwood Formation ◽  
Metabolizing Enzymes ◽  
Sucrose Metabolizing Enzymes ◽  
A Minor

Summary In trunks of Juglans nigra and the hybrid J. major × J. regia, the presence of non-structural carbohydrates, sucrose synthesizing and degrading enzymes, and their correlation with heartwood formation was investigated. Contents of starch and sucrose were highest in the youngest sapwood, decreased with increasing age of the tissue, and were absent in the heartwood. Pools of the monosaccharides glucose and fructose were low in the sapwood, and fructose was absent from the heartwood. Glucose transiently increased at the sapwood heartwood boundary in trunks of the hybrid. In black walnut stems, however, glucose started to accumulate within the transition zone and reached considerable amounts in the heartwood. Cold-adaptation in walnut wood was characterized by accumulation of soluble sugars. Sucrose formation was enabled by enhanced rates of sucrose-phosphate synthase (SPS, EC 2.4.1.14). Mid-winter starch-sugar interconversion was accompanied by increases in the activity of sucrose synthase (SuSy, EC 2.4.1.13; black walnut), or acid invertases (EC 3.2.1.26; hybrid). In the tissues undergoing heartwood formation, sucrose breakdown was enhanced from late summer until early winter. Sucrolysis was dominated by acid invertases with minor contribution of sucrose synthase. The catalytic activity of UDP-glucose pyrophosphorylase (EC 2.7.7.9), involved in the metabolization of the sucrose cleavage products, followed this seasonal trend and showed elevated activities from late summer until early winter. These data are further proof for the earlier made hypothesis (Hauch and Magel 1998) that the in situ synthesis of heartwood flavonoids relies on an interaction between primary (sucrose) and secondary metabolism. Flavonoids, however, constitute only a minor fraction in the heartwood of walnut and the bulk of heartwood phenolics seem to derive from transformation of phenolic precursors. Therefore, these recent findings together with earlier data are taken as evidence that more than one type of heartwood formation exists.

scholarly journals Sucrose Accumulation and Related Metabolizing Enzyme Activities in Seeded and Induced Parthenocarpic Muskmelons

2001 ◽  
Vol 126 (6) ◽  
pp. 676-680 ◽  
Author(s):  
Yasuyoshi Hayata ◽  
Xin-Xian Li ◽  
Yutaka Osajima
Keyword(s):  
Sucrose Synthase ◽  
Sucrose Phosphate Synthase ◽  
Invertase Activity ◽  
Activity Level ◽  
Sucrose Accumulation ◽  
Metabolizing Enzymes ◽  
Glucose Content ◽  
Seedless Fruit ◽  
Sucrose Metabolizing Enzymes ◽  
Metabolizing Enzyme

To clarify the cause of low sucrose accumulation in seedless `Crest Earl's' netted muskmelon [Cucumis melo L. (Reticulatus Group)] fruit induced by CPPU, the activity level of sucrose metabolizing enzymes was compared between seeded and seedless fruit. CPPU promoted growth of the ovary in both pollinated and nonpollinated flowers until 10 days after anthesis (DAA), and thereafter the growth rate of nonpollinated fruit was lower than in the controls. Sucrose accumulation of seedless fruit remained lower than in seeded fruit, but there was no difference in fructose and glucose content between seeded and seedless fruit. Acid invertase activity declined sharply 20 DAA in seeded and seedless fruit, and was hardly detectable at 35 DAA, when sucrose accumulation began. Neutral invertase (NI) activity in both seeded and seedless fruit decreased from 20 DAA until 35 DAA; thereafter, NI activity in seeded fruit remained relatively constant, with a small but insignificant increase in maturity. Sucrose synthase (SS-c: sucrose cleavage direction) activity in seeded fruit decreased from 20 to 30 DAA, and then increased as fruit matured, while SS-c activity in seedless fruit did not change during development. Sucrose phosphate synthase (SPS) activity in seeded fruit increased from 25 to 30 DAA and remained relatively constant until harvest. SPS activity in seedless fruit declined gradually from 30 to 45 DAA, then remained at a low level. Sucrose synthase (SS-s: sucrose synthesis direction) activity in seeded fruit increased rapidly after 30 DAA, concomitant with sucrose accumulation. In contrast, SS-s activity in seedless fruit increased only slightly after 30 DAA indicating levels of SS-s activity are closely related to sucrose accumulation in parthenocarpic seedless muskmelons. Chemical name used: [1-(2-chloro-4-pyridyl)-3-phenylurea] (CPPU).

scholarly journals Changes in Carbohydrates and Carbohydrate Metabolizing Enzymes during the Development, Maturation, and Ripening of Buttercup Squash (Cucurbita maxima D. `Delica')

1997 ◽  
Vol 122 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Donald E. Irving ◽  
Paul L. Hurst ◽  
Jonathan S. Ragg
Keyword(s):  
Sucrose Synthase ◽  
Dry Matter ◽  
Sucrose Phosphate Synthase ◽  
Early Growth ◽  
Dry Matter Accumulation ◽  
Metabolizing Enzymes ◽  
Developmental Growth ◽  
Low Concentrations ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

During this study, we divided the developmental growth pattern of buttercup squash into three phases: 1) early growth, from flowering up to 30 days after flowering; 2) maturation, from 30 days until 60 days after flowering (or harvest); and 3) ripening, from 60 days (or harvest) until ≈100 days after flowering. Harvest occurred at 48 days after flowering. Fruit growth (expansion), starch, and dry matter accumulation were largely completed during early growth, and there was a progressive decline in the respiration rate. Extractable activities of acid and alkaline invertases, sucrose synthase, alkaline α-galactosidase, and sucrose phosphate synthase (assayed with saturating substrates) were high initially but declined markedly during this phase. Glucose, fructose, and low concentrations of raffinose saccharides were present, but no sucrose was detected. During maturation, starch and dry matter remained nearly constant and sucrose began to accumulate. During ripening, starch was degraded, sucrose synthase activity was significant but relatively constant, sucrose phosphate synthase activity increased, and sucrose continued to accumulate.

scholarly journals SUGAR METABOLIZING ENZYMES IN CARROT ROOTS FROM POPULATIONS VARYING IN SUGAR TYPE AND CONCENTRATION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 591b-591
Author(s):  
Philipp W. Simon
Keyword(s):  
Sucrose Synthase ◽  
Sucrose Phosphate Synthase ◽  
Reducing Sugar ◽  
Total Sugar ◽  
Sugar Concentration ◽  
Metabolizing Enzymes ◽  
Developmental Analysis ◽  
Reducing Sugar Concentration ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

Four carrot populations with low total sugar/low reducing sugar concentration, low total sugar/high reducing sugar concentration, high total sugar/low reducing sugar concentration, and high total sugar/high reducing sugar concentration were compared for pH 4.5 invertase, pH 7.5 invertase, sucrose synthase, and sucrose phosphate synthase activity. Invertase activities correlated well with reducing sugar concentration. Sucrose synthase and sucrose phosphate synthase activities were low in all populations. Total sugar level was not well-correlated with the activity of any enzyme measured. Developmental analysis indicated some reduction in enzyme activity as roots grew.

scholarly journals Seasonal Fluctuations of Some Enzymes Relating to Sucrose and Sorbitol Metabolism in Peach Fruit

1990 ◽  
Vol 115 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Takaya Moriguchi ◽  
Tetsuro Sanada ◽  
Shohei Yamaki
Keyword(s):  
Sucrose Synthase ◽  
Prunus Persica ◽  
Early Stage ◽  
Sucrose Phosphate Synthase ◽  
Acid Invertase ◽  
Peach Fruit ◽  
Development Activity ◽  
Stage Of Development ◽  
Sugar Levels ◽  
Sucrose Phosphate

Sugar levels and composition were determined in developing `Hakuto' peach (Prunus persica Batsch var. vulgaris Maxim.) fruit. Glucose and fructose in nearly equal amounts were the predominant sugars detected during the early stage of development. Sucrose subsequently began to accumulate and was the predominant sugar in mature fruit. Sorbitol remained at a low level throughout development. The large increase in the amount of sucrose was accompanied by a rapid increase in sucrose synthase (EC 2.4.1.13) activity. Sucrose phosphate synthase (EC 2.4.1.14) was also detected in flesh extracts, but the activities were low throughout development. Acid invertase (EC 3.2.1.26) activity was highest in young fruit and declined with development. Activity, however, increased again at a later stage of development. Peach fruit contained appreciable sorbitol oxidase activity, while other sorbitol-related enzymes were barely detectable, suggesting that transported sorbitol was predominantly converted to glucose. These results suggest that the supply of glucose and fructose depends on acid invertase and sorbitol oxidase, and that accumulation of sucrose depends on-sucrose synthase.

Carbohydrate Storage and Mobilisation by the Culm of Wheat Between Heading and Grain Maturity: the Relation to Sucrose Synthase and Sucrose-Phosphate Synthase

1994 ◽  
Vol 21 (3) ◽  
pp. 255 ◽  
Author(s):  
IF Wardlaw ◽  
J Willenbrink
Keyword(s):  
Sucrose Synthase ◽  
Flag Leaf ◽  
Sucrose Phosphate Synthase ◽  
Leaf Sheath ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Carbohydrate Storage ◽  
Stem Reserves ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

Wheat plants grown under non-stress conditions at a dayhight temperature of 18/13�C under glasshouse conditions from head emergence to maturity showed a maximum accumulation of water-soluble, non-structural carbohydrates 20-25 days after anthesis. This storage was largely as fructans with the timing and amount of storage and mobilisation varying between cultivars, although the maximum concentration (fructose equivalents per unit stem fresh weight) was similar in all cultivars. The main storage in the culm was located in the lower part of the peduncle enclosed by the flag leaf sheath, in the penultimate internode and for one cultivar also in the flag leaf sheath. 14CO2 pulse-chase studies showed that there was a considerable delay in the incorporation of flag leaf assimilates into stem fructans, a delay probably associated with transfer and metabolic processes in the stem itself. At anthesis, when soluble carbohydrates were rapidly accumulating in the culm, the level of activity of sucrose synthase (SS) in the penultimate internode was much greater than that of sucrose phosphate synthase (SPS). The activity of SS declined rapidly as active storage ceased. This pattern was the reverse of that found in the leaf where SPS, rather than SS, was initially high and declined towards maturity. These changes are discussed in relation to the possible role of sucrose synthesising enzymes, particularly SS, in the accumulation and mobilisation of stem reserves in wheat.

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