Antioxidant enzymatic activity is linked to waterlogging stress tolerance in citrus

Abstract

Soil flooding constitutes a seasonal factor that negatively affects plant performance and crop yields. In this work, the relationship between oxidative damage and flooding sensitivity was addressed in three citrus genotypes with different abilities to tolerate waterlogging. We examined leaf visible damage, oxidative damage in terms of malondialdehyde (MDA) concentration, leaf proline concentration, leaf and root ascorbate and glutathione contents and the antioxidant enzyme activities superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), catalase (EC 1.11.1.6) and glutathione reductase (EC 1.8.1.7). No differences in the extent of oxidative damage relative to controls were found among genotypes. However, a different ability to delay the apparition of oxidative damage was associated to a higher tolerance to waterlogging. This ability was linked to an enhanced activated oxygen species' scavenging capacity in terms of an increased antioxidant enzyme activity and higher content in polar antioxidant compounds. Therefore, the existence of a direct relationship between stress sensitivity and the early accumulation of MDA is proposed. In addition, data indicate that the protective role of proline has to be considered minimal as its accumulation was inversely correlated with tolerance to the stress. The positive antioxidant response in Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) and Citrumelo CPB 4475 (Poncirus trifoliata L. Raf. x Citrus paradisi L. Macf.) might be responsible for a higher tolerance to flooding stress, whereas in Cleopatra mandarin (Citrus reshni Hort. Ex Tan.), the early accumulation of MDA seems to be associated to an impaired ability for H2O2 scavenging.

Photosynthetic gas exchange, chlorophyll fluorescence, antioxidant enzymes, and growth responses of Jatropha curcas during soil flooding

“…The enhanced stress induces activities of these enzymes in seedlings subjected to soil flooding to protect them from the stress (Liu et al, 2006;Arbona et al, 2008;BaileySerres and Voesenek, 2008). Several enzymes (superoxide dismutase, catalase, peroxidase, and glutathione peroxidase) scavenging ROS and low molecular mass antioxidants (ascorbate, glutathione, phenolics, and tocopherols) extend tolerance against stress (Noctor and Foyer, 1998;Blokhina et al, 2003).…”

Expression of antioxidant defense genes in mung bean (Vigna radiata L.) roots under water-logging is associated with hypoxia tolerance

“…The degree of increase in total SOD activity in wheat roots under anoxia was reported to be positively correlated with duration of anoxia (Van Toai and Bolles 1991). Arbona et al (2008) reported that water-logging induced positive antioxidant response in citrus cultivars Carrizo citrange and Citrumelo CPB 4475 might be responsible for a higher tolerance to flooding stress, whereas the susceptibility of Cleopatra mandarin could be due to less activity of antioxidant enzymes. Wang and Jiang (2007) reported that SOD and APX were mainly involved in water-logging induced antioxidant responses, and the partial water-logging could also significantly affect root antioxidant activities, particularly in water-loggingsensitive cultivar.…”

Stress responses of spring rape plants to soil flooding

“…According to Bakh-Engler theory, peroxidation processes occur permanently and unavoidably in the cells of living organisms. The relationship between the concentrations of hydrogen peroxide and MDA in roots and leaves of various plants exposed to soil flooding was repeatedly demonstrated (Asada, 2006) and the existence of a direct relationship between stress sensitivity and the early accumulation of MDA was shown (Arbona et al, 2008). Usually soil hypoxia increased the MDA concentration, especially in intolerant species (Chen and Qualls, 2003;Yordanova and Popova, 2007).…”

“…The developmental expression and tissue-specific responses of each gene member to hypoxic stress was demonstrated on various species (Garnczanska 2002;Preiszner et al, 2001;Wignarajah et al, 2006). Agrophys., 2012Agrophys., , 26, 347-353 doi: 10.2478 (Arbona et al, 2008, Balakhnina et al, 2009 (Asada, 2006;Blokhina et al, 2002). The pertinent literature presents data on correlation of the degree of resistance to extreme temperatures, salinity, drought and other stress factors with the free proline concentration in the plant tissues.…”