Antisense inhibition of the plastidial glucose-6-phosphate/phosphate translocator in Vicia seeds shifts cellular differentiation and promotes protein storage

摘要: The glucose-6-phosphate/phosphate translocator (GPT) acts as an importer of carbon into the plastid. Despite potential importance GPT for storage in crop seeds, its regulatory role biosynthetic pathways that are active during seed development is poorly understood. We have isolated GPT1 from Vicia narbonensis and studied using a transgenic approach based on seed-specific legumin promoter LeB4. highly expressed vegetative sink tissues, flowers young seeds. In embryo, localized upregulation at onset coincides with starch accumulation. Embryos plants expressing antisense showed significant reduction (up to 55%) specific transport rate glucose-6-phosphate determined proteoliposomes prepared embryos. Furthermore, amyloplasts developed later were smaller size, while expression genes encoding plastid-specific translocators proteins involved biosynthesis was decreased. Metabolite analysis stable isotope labelling demonstrated also reduced, although protein increased. This metabolic shift characterized by related nitrogen uptake storage, morphological variation protein-storing vacuoles, crude content mature seeds transgenics up 30% higher than wild-type. These findings provide evidence (1) prevailing level abundance/activity rate-limiting synthesis developing (2) exerts controlling function assimilate partitioning protein, (3) essential differentiation embryonic plastids maturation.