Photosynthetic and antioxidant responses to drought during sugarcane ripening

Autor(es)

Sales, C. R. G. ^[1] ; Marchiori, P. E. R. ^[1] ; Machado, R. S. ^[1] ; Fontenele, A. V. ^[2] ; Machado, E. C. ^[1] ; Silveira, J. A. G. ^[2] ; Ribeiro, R. V. ^[3]

Afiliação do(s) autor(es)

^[1] Agron Inst IAC, Ctr Res & Dev Ecophysiol & Biophys, Lab Plant Physiol Coaracy M Franco, BR-13012970 Campinas, SP - Brazil

^[2] Univ Fed Ceara, Dept Biochem & Mol Biol, Lab Plant Metab, BR-60455970 Fortaleza, Ceara - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Dept Plant Biol, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Photosynthetica; v. 53, n. 4, p. 547-554, DEC 2015.
• Citações Web of Science: 14

Resumo

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. (AU)

• Processo FAPESP: 08/57495-3 - Integrando características fisiológicas, morfológicas e anatômicas para entender o rendimento diferencial de sacarose em genótipos de cana-de-açúcar
• Beneficiário: Eduardo Caruso Machado
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático