Physiological and biochemical responses of two sugarcane genotypes growing under free-air ozone exposure

Autor: Fernanda C.C. Marcos, Bárbara Baêsso Moura, Eduardo Caruso Machado, Rafael Vasconcelos Ribeiro, Yasutomo Hoshika, Neidiquele M. Silveira, Elena Paoletti
Rok vydání: 2018
Předmět:
Zdroj: Environmental and experimental botany 153 (2018): 72–79. doi:10.1016/j.envexpbot.2018.05.004
info:cnr-pdr/source/autori:Moura B.B., Hoshika Y., Silveira N.M., Marcos F.C.C., Machado E.C., Paoletti E., Ribeiro R.V./titolo:Physiological and biochemical responses of two sugarcane genotypes growing under free-air ozone exposure/doi:10.1016%2Fj.envexpbot.2018.05.004/rivista:Environmental and experimental botany/anno:2018/pagina_da:72/pagina_a:79/intervallo_pagine:72–79/volume:153
ISSN: 0098-8472
DOI: 10.1016/j.envexpbot.2018.05.004
Popis: Biomass accumulation, physiological and biochemical responses of sugarcane to ozone (O-3) were evaluated in two genotypes (IACSP94-2094 and IACSP95-5000) in a realistic free-air O-3 exposure system. Our aims were to investigate the mechanisms involved in O-3 detoxification and verify whether such mechanisms are genotype dependent. Plants were exposed to ambient air (Amb.) and ambient air plus 40% increase in O-3 concentration (x1.4) for 90 days. Plants at x1.4 O-3 showed reductions in leaf gas exchange and biomass production with consistent differences between the genotypes. Photosynthesis of IACSP95-5000 was more sensitive to elevated 03 as compared to IACSP94-2094. As a primary response, IACSP94-2094 showed reductions in stomatal conductance due to elevated 03, thus avoiding oxidative stress and maintaining CO2 assimilation for longer. As a consequence, IACSP94-2094 produced more biomass, and stalks had more soluble sugar concentration than IACSP95-5000. Leaf concentrations of O-2(-) and H2O2 in plants exposed to x1.4 O-3 were not enhanced, with such unexpected result suggesting that sugarcane plants have an effective antioxidant system to avoid O-3-induced damage. In both genotypes, increases in ascorbate peroxidase activity was directly related to decreases in leaf H2O2 concentration. In IACSP94-2094, however, catalase pathway was also stimulated for detoxifying H2O2. We concluded that sugarcane sensitivity to O-3 is genotype-dependent and then it is possible to reduce the deleterious effects of high O-3 levels on sugarcane physiology and biomass production by growing tolerant genotypes in polluted areas.
Databáze: OpenAIRE
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