title: Enhancing the expression of starch synthase class IV results in increased levels of both transitory and long-term storage starch.
abstract: Starch is an important renewable raw material with an increasing number of applications. Several attempts have been made to obtain plants that produce modified versions of starch or higher starch yield. Most of the approaches designed to increase the levels of starch have focused on the increment of the amount of ADP-glucose or ATP available for starch biosynthesis. In this work, we show that the overexpression of starch synthase class IV (SSIV) increases the levels of starch accumulated in the leaves of Arabidopsis by 30%-40%. In addition, SSIV-overexpressing lines display a higher rate of growth. The increase in starch content as a consequence of enhanced SSIV expression is also observed in long-term storage starch organs such as potato tubers. Overexpression of SSIV in potato leads to increased tuber starch content on a dry weight basis and to increased yield of starch production in terms of tons of starch/hectare. These results identify SSIV as one of the regulatory steps involved in the control of the amount of starch accumulated in plastids.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-US, Sevilla, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Gámez-Arjona
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Sandy
authors.initials: S
authors.lastname: Raynaud
authors.forename: Edurne
authors.initials: E
authors.lastname: Baroja-Fernández
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Muñoz
authors.forename: Miroslav
authors.initials: M
authors.lastname: Ovecka
authors.forename: Paula
authors.initials: P
authors.lastname: Ragel
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Bahaji
authors.forename: Javier
authors.initials: J
authors.lastname: Pozueta-Romero
authors.forename: Ángel
authors.initials: Á
authors.lastname: Mérida
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins; D050260:Carbohydrate Metabolism; D003001:Cloning, Molecular; D005453:Fluorescence; D018506:Gene Expression Regulation, Plant; D058685:Genetic Pleiotropy; D017440:Photoperiod; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D035281:Plant Tubers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000235:genetics / Q000378:metabolism; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism*; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000378:metabolism*; D013214:Starch Synthase / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D055314:Seed Storage Proteins; D013213:Starch; D013214:Starch Synthase; C520418:starch synthase IV, Arabidopsis