title: Transcriptional coordination and abscisic acid mediated regulation of sucrose transport and sucrose-to-starch metabolism related genes during grain filling in wheat (Triticum aestivum L.).
abstract: Combining physiological, molecular and biochemical approaches, this study investigated the transcriptional coordination and abscisic acid (ABA) mediated regulation of genes involved in sucrose import and its conversion to starch during grain filling in wheat. Sucrose import appears to be mediated by seed localized TaSUT1, mainly TaSUT1D, while sucrose cleavage by TaSuSy2. Temporal overlapping of the transcriptional activation of AGPL1 and AGPS1a that encode AGPase with that of the above genes suggests their significance in the synthesis of ADP-glucose; TaAGPL1A and TaAGPL1D contributing the majority of AGPL1 transcripts. ABA induced repressions of TaSUT1, TaSuSy2, TaAGPL1 and TaAGPS1a imply that ABA negatively regulates sucrose import into the endosperm and its subsequent metabolism to ADP-glucose, the substrate for starch synthesis. The formations of amyloses and amylopectin from ADP-glucose appear to be mediated by specific members of GBSS, and SS, SBE and DBE gene families, and the ABA-induced transcriptional change in most of these genes implies that ABA regulates amylose and amylopectin synthesis. The findings provide insights into the molecular mechanisms underlying the coordination and ABA mediated regulation of sucrose transport into the developing endosperm and its subsequent metabolism to starch during grain filling in wheat.
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Shalini
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Kirandeep K
authors.initials: KK
authors.lastname: Deol
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Konstanin
authors.initials: K
authors.lastname: Kulichikhin
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Claudio
authors.initials: C
authors.lastname: Stasolla
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Anita
authors.initials: A
authors.lastname: Brûlé-Babel
authors.affiliation: Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada. Electronic address: belay.ayele@umanitoba.ca.
authors.forename: Belay T
authors.initials: BT
authors.lastname: Ayele
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D001692:Biological Transport; D002523:Edible Grain / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D013395:Sucrose; D000040:Abscisic Acid; D013213:Starch
keywords: ABA; Genes/homeologues; Grain filling; Sucrose import; Sucrose to starch metabolism; Wheat