Author(s): AVILA, R. G.; MAGALHAES, P. C.; SILVA, E. M. da; GOMES JÚNIOR, C. C.; LANA, U. G. de P.; ALVARENGA, A. A. de; SOUZA, T. C. de

Summary: This study was conducted to assess the effects of silicon treatments on architecture and morphometry of root systems of sorghum plants grown at two different soil water levels and to elucidate whether physiological improvements caused by silicon were related to morphometric modifications of the root system. Methods Plants of the sorghum genotype BRS332 which is sensitive to drought at pre-flowering stage were used in this study. Theseplantsweregrowninagreenhouse,eitheratfieldcapacityorunderwaterdeficiency,andweretreatedwithsiliconorwere untreated. Leaf water potential was evaluated at noon, and gas exchange, photosynthetic pigment levels, relative aquaporin expression, root system morphometry, and grain yield were assessed. Results Silicontreatmentsmitigatedtheeffectsofwaterdeficiencyonleafpotential,photosynthesis,instantaneouscarboxylation efficiency, and morphometry of the root system. These positive effects contributed to a higher grain yield, and thus indicated highertolerancetodrought.Thebeneficialeffectsofsiliconalsooccurredinplantsgrownatfieldcapacity.Silicontreatmentsdid not increase the relative expression of aquaporin genes. However, we observed that expression of aquaporin TIP4 responded more strongly to drought than that of aquaporins PIP1;6 and PIP1;3/1;4. Conclusion Weconcludethatsiliconsupplementationincreasesthetoleranceofsorghumplantstodroughtbyincreasinggrowth of the root system and mitigating adverse effects of drought on photosynthesis.

Publication year: 2020

Types of publication: Journal article

Unit: Embrapa Maize & Sorghum

Keywords: Deficiência Hídrica, Fotossíntese, Sistema Radicular, Sorgo