Bahaji, AbdellatifAlmagro Zabalza, GoizederEzquer, IgnacioGámez Arcas, SamuelSánchez López, Ángela MaríaMuñoz Pérez, Francisco JoséBarrio, Ramón JoséSampedro, M. CarmenDiego, Nuria deSpíchal, LukásDolezal, KarelTarkowská, DanuseCaporali, ElisabettaMendes, Marta AdelinaBaroja Fernández, EdurnePozueta Romero, Javier2019-08-262019-08-2620181040-465110.1105/tpc.18.00312https://academica-e.unavarra.es/handle/2454/34671The plastid-localized phosphoglucose isomerase isoform PGI1 is an important determinant of growth in Arabidopsis thaliana, likely due to its involvement in the biosynthesis of plastidial isoprenoid-derived hormones. Here, we investigated whether PGI1 also influences seed yields. PGI1 is strongly expressed in maturing seed embryos and vascular tissues. PGI1-null pgi1-2 plants had ∼60% lower seed yields than wild-type plants, with reduced numbers of inflorescences and thus fewer siliques and seeds per plant. These traits were associated with low bioactive gibberellin (GA) contents. Accordingly, wild-type phe-notypes were restored by exogenous GA application. pgi1-2 seeds were lighter and accumulated ∼50% less fatty acids (FAs) and ∼35% less protein than wild-type seeds. Seeds of cytokinin-deficient plants overexpressing CYTOKININ OXIDASE/DE-HYDROGENASE1 (35S:AtCKX1) and GA-deficient ga20ox1 ga20ox2 mutants did not accumulate low levels of FAs, and exogenous application of the cytokinin 6-benzylaminopurine and GAs did not rescue the reduced weight and FA content of pgi1-2 seeds. Seeds from reciprocal crosses between pgi1-2 and wild-type plants accumulated wild-type levels of FAs and proteins. Therefore, PGI1 is an important determinant of Arabidopsis seed yield due to its involvement in two processes: GA-mediated reproductive development and the metabolic conversion of plastidial glucose-6-phosphate to storage reserves in the embryo.58 p.application/pdfeng© 2018 American Society of Plant Biologists. All rights reserved.Plastidial phosphoglucose isomeraseArabidopsis thalianaSeed yieldsGibberellinFatty acidsWild type plantsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccessAcceso abierto / Sarbide irekia