Integrated functions among multiple starch synthases determine both amylopectin chain length and branch linkage location in Arabidopsis leaf starch

This study assessed the impact on starch metabolism in Arabidopsis leaves of simultaneously eliminating multiple soluble starch synthases (SS) from among SS1, SS2, and SS3. Double mutant ss1- ss2- or ss1- ss3- lines were generated using confirmed null mutations. These were compared to the wild type, each single mutant, and ss1- ss2- ss3- triple mutant lines grown in standardized environments. Double mutant plants developed similarly to the wild type, although they accumulated less leaf starch in both short-day and long-day diurnal cycles. Despite the reduced levels in the double mutants, lines containing only SS2 and SS4, or SS3 and SS4, are able to produce substantial amounts of starch granules. In both double mutants the residual starch was structurally modified including higher ratios of amylose:amylopectin, altered glucan chain length distribution within amylopectin, abnormal granule morphology, and altered placement of α(1→6) branch linkages relative to the reducing end of each linear chain. The data demonstrate that SS activity affects not only chain elongation but also the net result of branch placement accomplished by the balanced activities of starch branching enzymes and starch debranching enzymes. SS3 was shown partially to overlap in function with SS1 for the generation of short glucan chains within amylopectin. Compensatory functions that, in some instances, allow continued residual starch production in the absence of specific SS classes were identified, probaby accomplished by the granule bound starch synthase GBSS1.ANR Génoplante GPLA0611GEuropean Union-FEDER, Région Nord Pas de Calais ARCir PlantTEQ5National Science Foundation DBI-0209789Comisión Interministerial de Ciencia y Tecnología BIO2009-07040Junta de Andalucía P09-CVI-470

The Enginering Important Components of Jatibarang Dam, Semarang, Indonesia

Semarang City suffers from inundation caused by storm rainfall and high tide due to its low-lying topography along the coastal area. The Jatibarang Dam purpose is to develop a new source of water for Semarang City and to control the flood discharge of West Floodway as the biggest river in Semarang. Also, it has been recognized that the combination of the Jatibarang Dam and the rivers improvement is the most feasible flood control measure. The flood control scheme will be established to protect Semarang City from the 50-year return period flood and the water resources development scheme is planned to assure the water to the 10-year draught. The design flooding will be controlled by the Jatibarang Dam. About 270 m3/s of 50-year return period flood at Jatibarang dam will be controlled by the dam and the discharge from dam will be reduced to 100 m3/s. The Engineering important components of the Dam are diversion tunnel, dam structure, spillway and conduit of power works.Each component will be elaborated in this article

Proteome and phosphoproteome analysis of starch granule-associated proteins from normal maize and mutants affected in starch biosynthesis

In addition to the exclusively granule-bound starch synthase GBSSI, starch granules also bind significant proportions of other starch biosynthetic enzymes, particularly starch synthases (SS) SSI and SSIIa, and starch branching enzyme (BE) BEIIb. Whether this association is a functional aspect of starch biosynthesis, or results from non-specific entrapment during amylopectin crystallization, is not known. This study utilized genetic, immunological, and proteomic approaches to investigate comprehensively the proteome and phosphoproteome of Zea mays endosperm starch granules. SSIII, BEI, BEIIa, and starch phosphorylase were identified as internal granule-associated proteins in maize endosperm, along with the previously identified proteins GBSS, SSI, SSIIa, and BEIIb. Genetic analyses revealed three instances in which granule association of one protein is affected by the absence of another biosynthetic enzyme. First, eliminating SSIIa caused reduced granule association of SSI and BEIIb, without affecting GBSS abundance. Second, eliminating SSIII caused the appearance of two distinct electrophoretic mobility forms of BEIIb, whereas only a single migration form of BEIIb was observed in wild type or any other mutant granules examined. Third, eliminating BEIIb caused significant increases in the abundance of BEI, BEIIa, SSIII, and starch phosphorylase in the granule, without affecting SSI or SSIIa. Analysis of the granule phosphoproteome with a phosphorylation-specific dye indicated that GBSS, BEIIb, and starch phosphorylase are all phosphorylated as they occur in the granule. These results suggest the possibility that starch metabolic enzymes located in granules are regulated by post-translational modification and/or protein–protein interactions

L'artiste dans le monde arabe : entre crises politiques et pétrodollars

Gregory Buchakjian Télécharger au format pdf Communication présentée le 20 janvier 2014 Article publié le 11 janvier 2019 Résumé: Depuis les attentats du 11 septembre, l’art contemporain du monde arabe connaît un engouement sans précédent. Face à cette effervescence, quelle est la place des artistes de cette région, sachant que la plupart de ces derniers sont originaires de pays en guerre et / ou en profonde crise : Egypte, Irak, Liban, Palestine, Syrie… Comment concilier ces co..

La musique qui aveugle, la musique qui délivre : les représentations du Dernier concert et du Sommeil des femmes dans l’art du Gandhāra

Magali Vacherot Télécharger au format PDF Article soumis en 2015 Article publié le 25 mars 2015 Résumé L’art du Gandhara ne montre pas le Bouddha en situation de jeu. Cependant, les scènes de concert données en l’honneur de Siddhārtha par les femmes du palais sont assez courantes et présentes dans l’iconographie et les sources anciennes. L’analyse du « Dernier Concert » et de la « Femme Endormie » ( qui en est la suite immédiate) montre qu’au dela du plaisir vain, il s’agit bien d’un épisode..