title: Exogenous nitric oxide improves sugarcane growth and photosynthesis under water deficit.
abstract: Nitric oxide (NO)-mediated redox signaling plays a role in alleviating the negative impact of water stress in sugarcane plants by improving root growth and photosynthesis. Drought is an environmental limitation affecting sugarcane growth and yield. The redox-active molecule nitric oxide (NO) is known to modulate plant responses to stressful conditions. NO may react with glutathione (GSH) to form S-nitrosoglutathione (GSNO), which is considered the main reservoir of NO in cells. Here, we investigate the role of NO in alleviating the effects of water deficit on growth and photosynthesis of sugarcane plants. Well-hydrated plants were compared to plants under drought and sprayed with mock (water) or GSNO at concentrations ranging from 10 to 1000 μM. Leaf GSNO sprayed plants showed significant improvement of relative water content and leaf and root dry matter under drought compared to mock-sprayed plants. Additionally, plants sprayed with GSNO (≥ 100 μM) showed higher leaf gas exchange and photochemical activity as compared to mock-sprayed plants under water deficit and after rehydration. Surprisingly, a raise in the total S-nitrosothiols content was observed in leaves sprayed with GSH or GSNO, suggesting a long-term role of NO-mediated responses to water deficit. Experiments with leaf discs fumigated with NO gas also suggested a role of NO in drought tolerance of sugarcane plants. Overall, our data indicate that the NO-mediated redox signaling plays a role in alleviating the negative effects of water stress in sugarcane plants by protecting the photosynthetic apparatus and improving shoot and root growth.
authors.affiliation: Laboratory of Plant Physiology "Coaracy M. Franco", Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, SP, Brazil.
authors.forename: Neidiquele M
authors.initials: NM
authors.lastname: Silveira
authors.affiliation: Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.|School of Biological Sciences, Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: Lucas
authors.initials: L
authors.lastname: Frungillo
authors.affiliation: Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Fernanda C C
authors.initials: FC
authors.lastname: Marcos
authors.affiliation: Department of Exact and Earth Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
authors.forename: Milena T
authors.initials: MT
authors.lastname: Pelegrino
authors.affiliation: Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Marcela T
authors.initials: MT
authors.lastname: Miranda
authors.affiliation: Department of Exact and Earth Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
authors.forename: Amedea B
authors.initials: AB
authors.lastname: Seabra
authors.affiliation: Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Ione
authors.initials: I
authors.lastname: Salgado
authors.affiliation: Laboratory of Plant Physiology "Coaracy M. Franco", Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, SP, Brazil.
authors.forename: Eduardo C
authors.initials: EC
authors.lastname: Machado
authors.affiliation: Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil. rvr@unicamp.br.
authors.forename: Rafael V
authors.initials: RV
authors.lastname: Ribeiro
mesh_terms: D000704:Analysis of Variance; D002245:Carbon Dioxide / Q000378:metabolism; D003681:Dehydration; D055864:Droughts; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000378:metabolism / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D026422:S-Nitrosoglutathione / Q000378:metabolism / Q000494:pharmacology; D031786:Saccharum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014867:Water / Q000378:metabolism / Q000494:pharmacology
chemical_list: D020030:Nitric Oxide Donors; D014867:Water; D002245:Carbon Dioxide; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione
keywords: Drought; Photochemistry; S-Nitrosoglutathione; Saccharum spp.; Water stress