Assessment of the ozone tolerance of two soybean cultivars (Glycine max cv. Sambaíba and Tracajá) cultivated in Amazonian areas

Abstract

Brazilian soybean cultivars (Glycine max Sambaíba and Tracajá) routinely grown in Amazonian areas were exposed to filtered air (FA) and filtered air enriched with ozone (40 and 80 ppb, 6 h/day for 5 days) to assess their level of tolerance to this pollutant by measuring changes in key biochemical, physiological, and morphological indicators of injury and in enzymatic and non-enzymatic antioxidants. Sambaíba plants were more sensitive to ozone than Tracajá plants, as revealed by comparing indicator injury responses and antioxidant stimulations. Sambaíba exhibited higher visible leaf injury, higher stomatal conductance, and a severe decrease in the carbon assimilation rate. Higher ozone level (80 ppb) caused an increase in cell death in both cultivars. Levels of malondialdehyde and hydrogen peroxide also increased in Tracajá exposed under 80 ppb. Sambaíba plants exhibited decreases in ascorbate and glutathione levels and in enzymatic activities associated with these antioxidants. The higher tolerance of the Tracajá soybean appeared to be indicated by reduced physiological injuries and lower stomatal conductance, which might decrease the influx of ozone and enhance oxidation-reduction reactions involving catalase, ascorbate peroxidase, ascorbate, and glutathione, most likely stimulated by higher hydrogen peroxide.

Sulfur Metabolism and Stress Defense Responses in Plants

“…Stress can be defined as any alteration in normal plant growth conditions (Boaretto et al 2014). Some of these alterations are related to temperature, salinity, water supply, ozone, soil acidification and heavy metal toxicity, among others (Azevedo et al 1998;Bulbovas et al 2014;Medici et al 2014;Nogueirol et al 2015). Studies of plants have been conducted to evaluate the effects of these changes on growth and development.…”

Protective effect of Mn(III)–desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max “Sambaiba”

“…The ozone exposure was performed during the summer of 2011 in closed chambers developed to expose the plants to air pollutants (Souza and Pagliuso 2009;Bulbovas et al 2014). The chambers were programmed to have a light (L)/dark (D) cycle of 10-h L/14-h D. During ozone exposure, the mean temperature, relative humidity, vapor pressure deficit, and photon flux density values were 25±2°C, 52±8 %, 1.21±0.88 kPa, and 674±133 μmol m −2 s −1 .…”

“…Studies performed in controlled environments and in the field have contributed to the understanding of the mechanisms underlying the effects of pollutants and their impact on vegetation (Inubushi et al 2003;Pleijel 2011;Souza et al 2013;Bulbovas et al 2014). According to these studies, ozone and acid rain are considered major contributors to oxidative damage in crops.…”

“…The present study was aimed at verifying the effect of MnDFB on the defenses of the Brazilian soybean cultivar Glycine max cv "Sambaiba" against oxidative stress caused by ozone and acid rain. According to Bulbovas et al (2014), the "Sambaiba" is a cultivar less effective in counteracting the oxidative stress imposed by ozone, and therefore, we selected this cultivar to test the MnDFB activity on antioxidant defenses.…”

Temporal dynamics of the response to Al stress in Eucalyptus grandis × Eucalyptus camaldulensis

“…In contrast, it is well known that Al induces oxidative stress and increases the activity of a number of antioxidant enzymes related to the detoxification of reactive oxygen species (ROS) and lipid peroxidation (Boscolo et al 2003, Giannakoula et al 2010, due to an imbalance in the cellular redox status that leads to oxidative stress (Gratão et al 2005, Boaretto et al 2014, a response that is quite similar to those produced by other types of stresses, such as exposure to ozone (Azevedo et al 1998, Bulbovas et al 2014, heavy metals (Gratão et al 2012, nutritional deficiencies (Lidon and Barreiro 1999, Muneer et al 2013), drought (Cia et al 2012, Boaretto et al 2014) and diseases (Lamb and Dixon 1997) and even the use of nanoparticles (Arruda et al 2015). Curiously, various aluminiumcontaining salts have also been shown to provide an alternative to the use of synthetic fungicides to control pathogens (Kolaei et al 2013).…”