The antioxidative response of two tomato species with different drought tolerances as a result of drought and cadmium stress combinations

Abstract

The effects of drought, cadmium (Cd) and drought-Cd combinations on antioxidant compounds, antioxidant enzymes and shoot growth were investigated for drought tolerant [Lycopersicon peruvianum (L.) Mill.] and sensitive of (Lycopersicon esculentum Mill. cv. Lukullus) tomato species. Drought-Cd combinations significantly decreased shoot growth in both species (P < 0.01), drought stress also decreased shoot growth in drought sensitive L. esculentum. Cd was accumulated higher in the roots of drought sensitive L. esculentum than drought tolerant L. peruvianum. The chlorophyll contents decreased in all stress treatments in L. esculentum but did not change in L. peruvianum. Carotenoid contents significantly increased in all stress treatments in both species (P < 0.01). Significant increases in the contents of carotenoids in both species under stress conditions seemed to be associated with a protective role against reactive oxygen species (ROS). Ascorbate (ASC) content decreased during drought stress while increased under Cd stress. Catalase (CAT) and glutathione reductase (GR) activities significantly increased under drought stress in L. peruvianum while decreased in L. esculentum (P < 0.001). Ascorbate peroxidase (APX) activity decreased under all stress treatments in both species. Drought and Cd stresses increased superoxide dismutase (SOD) activity in both species. The present data did not show a relation between drought tolerance and levels of antioxidative defence system that was induced from Cd. However, there is a clear relationship between Cd uptake and drought tolerance of plants.

Effect of abiotic stresses on the activity of antioxidative enzymes and contents of phytohormones in wild type and AtCKX2 transgenic tobacco plants

“…It is evident from literature data that different plant species differ considerably in their AOE activities in response to water deficit (Moran et al 1994, Zhang and Kirkham 1996, Ünyayar et al 2005. In this work we observed that activities of AOE in WT leaves were almost not affected during water deficit in contrast to roots where APX and GR activities increased upon stress.…”

Effects of benzoic acid and cadmium toxicity on wheat seedlings

“…Carotenoid was more sensitive towards stress as compared with chlorophyll in respective treatments. Single and combined stress treatment exhibited negative impact on carotenoid content of wheat seedling (Ünyayar et al, 2005;Mishra and Agrawal, 2006). The decrease in carotenoid content is harmful to chlorophyll because carotenoid protects chlorophyll from photooxidative destruction (Middleton and Teramura, 1993).…”

Alleviation of allelopathic stress of benzoic acid by indole acetic acid in Solanum lycopersicum

“…Production of reactive oxygen species (ROS) scavengers is an important device to increase tolerance against oxidative stress (Sairam et al, 1998). Superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) are antioxidant enzymes which detoxify ROS (Rubio et al, 2002;Ünyayar et al, 2005) and protect crop plants in oxidative stress. Yadav and Singh (2013) reported that BA at 0.5, 1.0 and 1.5 mM concentrations exhibited toxic effects on crop plants.…”