title: Silicon improves rice grain yield and photosynthesis specifically when supplied during the reproductive growth stage.
abstract: Silicon (Si) has been recognized as a beneficial element to improve rice (Oryza sativa L.) grain yield. Despite some evidence suggesting that this positive effect is observed when Si is supplied along the reproductive growth stage (from panicle initiation to heading), it remains unclear whether its supplementation during distinct growth phases can differentially impact physiological aspects of rice and its yield and the underlying mechanisms. Here, we investigated the effects of additions/removals of Si at different growth stages and their impacts on rice yield components, photosynthetic performance, and expression of genes (Lsi1, Lsi2 and Lsi6) involved in Si distribution within rice shoots. Positive effects of Si on rice production and photosynthesis were manifested when it was specifically supplied during the reproductive growth stage, as demonstrated by: (1) a high crop yield associated with higher grain number and higher 1000-grain weight, whereas the leaf area and whole-plant biomass remained unchanged; (2) an increased sink strength which, in turn, exerted a feed-forward effect on photosynthesis that was coupled with increases in both stomatal conductance and biochemical capacity to fix CO2; (3) higher Si amounts in the developing panicles (and grain husks) in good agreement with a remarkable up-regulation of Lsi6 (and to a lesser extent Lsi1). We suggest that proper levels of Si in these reproductive structures seem to play an as yet unidentified role culminating with higher grain number and size.
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Alyne O
authors.initials: AO
authors.lastname: Lavinsky
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Kelly C
authors.initials: KC
authors.lastname: Detmann
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Josimar V
authors.initials: JV
authors.lastname: Reis
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Rodrigo T
authors.initials: RT
authors.lastname: Ávila
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Matheus L
authors.initials: ML
authors.lastname: Sanglard
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Lucas F
authors.initials: LF
authors.lastname: Pereira
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Lílian M V P
authors.initials: LMVP
authors.lastname: Sanglard
authors.affiliation: Departamento de Fitopatologia, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Fabrício A
authors.initials: FA
authors.lastname: Rodrigues
authors.affiliation: Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Araújo
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil. Electronic address: fdamatta@ufv.br.
authors.forename: Fábio M
authors.initials: FM
authors.lastname: DaMatta
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D010788:Photosynthesis / Q000187:drug effects*; D025341:Principal Component Analysis; D012098:Reproduction / Q000187:drug effects; D012639:Seeds / Q000187:drug effects / Q000254:growth & development*; D012825:Silicon / Q000494:pharmacology*
chemical_list: D012825:Silicon
keywords: Crop yield; Gene expression; Oryza sativa; Photosynthesis; Photosynthetic limitations; Silicon