A sucrose-synthase gene of Vicia faba L.: expression pattern in developing seeds in relation to starch synthesis and metabolic regulation.
Copy-DNA clones encoding a single class of sucrose-synthase (SUCS; EC 2.4.1.13) subunit have been isolated and sequenced from a Vicia faba L. seed cotyledonary library. Southern analyses indicated the existence of only one gene. Transcript levels determined by Northern blot hybridisation steadily increased until the middle of development [25-35 days after flowering (DAF)] and declined thereafter. Sucrose levels approximately paralleled levels of SUCS mRNA. The activity of SUCS increased with decreasing fructose and glucose concentrations and peaked about 10 d later than mRNA levels. In-vitro culture experiments demonstrated that increasing the sucrose concentration leads to increased levels of SUCS mRNA. The SUCS mRNA was also synthesised in seed-coat tissue, but in lower amounts than in cotyledons and with a different developmental profile. The early peak level of SUCS mRNA (20 DAF) in seed coats coincided with the peak in the amount of sucrose and with a peak of transiently synthesised starch.
Heim
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Institut für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany.
Weber
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Bäumlein
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Wobus
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D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D004247:DNA; D007887:Fabaceae / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D015870:Gene Expression; D005964:Glucosyltransferases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D012333:RNA, Messenger / Q000378:metabolism; D015183:Restriction Mapping; D012639:Seeds / Q000201:enzymology; D013213:Starch / Q000096:biosynthesis*; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors
D012333:RNA, Messenger; D013395:Sucrose; D013213:Starch; D004247:DNA; D005964:Glucosyltransferases; C022699:sucrose synthase