caa a22 4500 605480990 CHVBK 20210128100418.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s11099-015-0146-x doi (NATIONALLICENCE)springer-10.1007/s11099-015-0146-x Photosynthetic and antioxidant responses to drought during sugarcane ripening [Elektronische Daten] [C. Sales, P. Marchiori, R. Machado, A. Fontenele, E. Machado, J. Silveira, R. Ribeiro] Water deficit is an important exogenous factor that enhances the influx of sucrose into sugarcane (Saccharum spp.) stem internodes during ripening, when photosynthetic ability in supplying sinks is essential. The aim of this study was to test the hypothesis that drought tolerance in sugarcane is associated with an effective antioxidant protection during the ripening phase that might maintain a favorable redox balance in chloroplasts and protect photosynthesis under drought conditions. Two commercial sugarcane varieties, IACSP94-2094 (tolerant) and IACSP96-2042 (sensitive), with contrasting behavior under water deficit, were subjected to water withholding during the ripening stage. Our results revealed that the tolerant variety was less affected by water deficit, maintaining photosynthesis for a longer period and showing a faster recovery after rehydration as compared to the sensitive one. As consequence, the tolerant variety faced lesser excess of light energy at PSII. The maintenance of photosynthesis under water deficit and its fast recovery after rehydration resulted in the lower leaf H2O2 concentration and favorable redox status in the drought-tolerant genotype, which was associated with stimulation of superoxide dismutase during ripening. Our results also revealed that ferric superoxide dismutase isoforms were strongly enhanced under drought conditions, playing an important role in chloroplast redox homeostasis. The Institute of Experimental Botany, 2015 chlorophyll fluorescence nationallicence leaf gas exchange nationallicence oxidative stress nationallicence water stress nationallicence AsA : ascorbic acid nationallicence AsA + DHA : total ascorbate concentration nationallicence APX : ascorbate peroxidase nationallicence C i : intercellular CO2 concentration nationallicence DAP : days after planting nationallicence DHA : dehydroascorbate or oxidized ascorbate nationallicence EXC : relative excess of light energy nationallicence FM : fresh mass nationallicence Fv/Fm : maximal quantum yield of PSII photochemistry nationallicence g s : stomatal conductance nationallicence NPQ : nonphotochemical quenching nationallicence P N : net photosynthetic rate nationallicence P N/ C i : instantaneous carboxylation efficiency nationallicence REF : reference condition nationallicence ROS : reactive oxygen species nationallicence SOD : superoxide dismutase nationallicence TBARS : thiobarbituric acid-reactive substances nationallicence VPDL : leaf-to-air vapour pressure deficit nationallicence WD : water-deficit condition nationallicence ΦPSII : effective quantum yield of PSII photochemistry nationallicence Ψw : leaf water potential nationallicence Sales C. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut Marchiori P. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut Machado R. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut Fontenele A. Laboratory of Plant Metabolism, Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-970, Fortaleza CE, Brazil aut Machado E. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut Silveira J. Laboratory of Plant Metabolism, Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-970, Fortaleza CE, Brazil aut Ribeiro R. Department of Plant Biology, Institute of Biology, University of Campinas, P.O. Box 6109, 13083-970, Campinas SP, Brazil aut Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/4(2015-12-01), 547-554 0300-3604 53:4<547 2015 53 11099 https://doi.org/10.1007/s11099-015-0146-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11099-015-0146-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sales C. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut NATIONALLICENCE 700 1- Marchiori P. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut NATIONALLICENCE 700 1- Machado R. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut NATIONALLICENCE 700 1- Fontenele A. Laboratory of Plant Metabolism, Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-970, Fortaleza CE, Brazil aut NATIONALLICENCE 700 1- Machado E. Laboratory of Plant Physiology ‘Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), P.O. Box 28, 13012-970, Campinas SP, Brazil aut NATIONALLICENCE 700 1- Silveira J. Laboratory of Plant Metabolism, Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-970, Fortaleza CE, Brazil aut NATIONALLICENCE 700 1- Ribeiro R. Department of Plant Biology, Institute of Biology, University of Campinas, P.O. Box 6109, 13083-970, Campinas SP, Brazil aut NATIONALLICENCE 773 0- Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/4(2015-12-01), 547-554 0300-3604 53:4<547 2015 53 11099