Mycorrhiza has a direct effect on reactive oxygen metabolism of drought-stressed citrus

Abstract

A greenhouse experiment was conducted to investigate the dynamic trend of symbiotic development in Citrus sinensis/Poncirus trifoliata trees colonized by Glomus versiforme during 12-day lasting drought and to evaluate correlation between symbiotic development and reactive oxygen metabolism of citrus. One year after planting, water was withheld from all trees for 12 days. During the drought stress mycorrhizal colonization and arbuscles showed a durative reduction. Mycorrhizal trees maintained significantly lower contents of superoxide anion, hydrogen peroxide and malondialdehyde than non-mycorrhizal control throughout the experiment. There were significantly greater activities of superoxide dismutase, guaiacol peroxidase and catalase in mycorrhizal trees throughout the drought stress period. Ascorbate and glutathione contents of mycorrhizal trees were notably higher than those of uninoculated ones during 12 days of drought stress. Correlation analysis showed that not vesicles and entry points but mycorrhizal colonization and arbuscules had a substantive direct effect on reactive oxygen metabolism. These results suggest that mycorrhizal colonization and arbuscles play a major role in improving reactive oxygen metabolism of drought-stressed citrus, thus inducing a lower oxidative damage.

Increased Tolerance of Citrus (<i>Citrus tangerina</i>) Seedlings to Soil Water Deficit after Mycorrhizal Inoculation: Changes in Antioxidant Enzyme Defense System

“…This is consistent with the findings of Wu and Zou (2009), who reported that mycorrhizal grafted citrus seedlings had significantly lower H 2 O 2 and O 2…”

Mycorrhizal Fungi to Alleviate Drought Stress on Plant Growth

“…The amelioration of stress resistance by AM symbiosis is often related to the enhancement of antioxidant levels or activities in plants (Wu et al 2006a, b;Wu and Zou 2009;Ruiz-Sánchez et al 2010;Baslam and Goicoechea 2012). RuizSánchez et al (2010) found that AM symbiosis ameliorated the response of plants to drought by improving photosynthetic performance but mainly through the accumulation of the antioxidant compound glutathione, which was concomitant with a reduction in oxidative damage to membrane lipids and to low cellular levels of hydrogen peroxide.…”

Differential Effects of Cold Stress on the Antioxidant Response of Mycorrhizal and Non-Mycorrhizal Jatropha curcas (L.) Plants

“…Thus, AM J. curcas plants could be accumulating these antioxidant compounds under cold stress to prevent lipid peroxidation. These compounds were not measured in this study, but a higher accumulation in AM plants subjected to drought stress has been reported in several plant species (Wu & Zou, 2009;Ruiz-Sánchez et al, 2011;Baslam et al, 2012). Moreover, a recent study has shown that the benefits of AM symbiosis not only rely in a lower oxidative stress in the host plant, but also restrict locally such oxidative stress, avoiding a systemic damage and allowing the plants to continue with their physiological processes (Bárzana et al, 2015).…”