Selenium Modifies the Effect of Short-Term Chilling Stress on Cucumber Plants

Abstract

The objective of this study was to investigate the effect of selenium (Se) supply (0, control; 2.5, 5, 10, or 20 μM) on cucumber (Cucumis sativus L.) cv. Polan F1 plants grown under short-term low temperature stress. About 14-16 day-old seedlings, grown at an optimal temperature (25/20°C; day/night), were exposed to short-term chilling stress with a day/night temperature of 10°C/5°C for 24 h, for a further 24 h at 20°C/15°C, and then transferred to 25/20°C (re-warming) for 7 days. Se did not affect the fresh weight (FW) of plants at a concentration of 2.5-10 μM, but in the presence of 20 μM Se, the biomass of shoots significantly decreased. The contents of chlorophylls and carotenoids witnessed no significant change after Se supplementation. Compared with the control, the Se-treated plants showed an increase of proline content in leaves, once after chilling and again after 7 days of re-warming. However, proline levels were much higher immediately after chilling than after re-warming. The malondialdehyde (MDA) content in the root of plants treated with 2.5-10 μM Se decreased directly after stress. This was in comparison with the plants grown without Se, whereas it increased in roots and leaves of plants exposed to 20 μM Se. Seven days later, the MDA level in the root of plants grown in the presence of Se was still lower than those of plants not treated with Se and generally witnessed no significant change in leaves. Although Se at concentrations of 2.5-10 μM modified the physiological response of cucumber to short-term chilling stress, causing an increase in proline content in leaves and diminishing lipid peroxidation in roots, the resistance of plants to low temperature was not clearly enhanced, as concluded on the basis of FW and photosynthetic pigments accumulation.

Selenium-Induced Up-Regulation of the Antioxidant Defense and Methylglyoxal Detoxification System Reduces Salinity-Induced Damage in Rapeseed Seedlings

“…Understanding the biochemical and molecular responses to salt stress is essential for the holistic perception of plant resistance mechanisms under salt stress. Recent studies have shown that, at low concentrations, Se can protect plants from several types of abiotic stress by enhancing the antioxidant capacity [14,16,31]. In this study, we investigated the possible regulatory role of exogenous Se on ascorbate (AsA) and glutathione (GSH) content; the activities of the AsA-GSH cycle; and the glyoxalase system enzymes, including glutathione S-transferase (GST), glutathione peroxidase (GPX), and catalase (CAT).…”

“…Recent studies have identified several beneficial effects of selenium (Se) for plants, even though Se is not considered to be a requirement for higher plants [12]. Some research groups have reported that Se cannot only promote growth and development of plants, but also increase resistance to certain abiotic stresses, e.g., salinity [13,14], drought [15], chilling [16], toxic metals [17], and UV irradiation [18]. Se exerts beneficial effects on the growth and stress tolerance of plants by enhancing the antioxidant capacity [13,19].…”

Alleviation of temperature stress by nutrient management in crop plants: a review

“…Recent studies have shown that Se at low concentrations can protect plants from several types of abiotic stresses (Hawrylak-Nowak et al, 2010 ;Valadabadi et al, 2010).Temperature stress (high temperature) can cause premature leaf senescence which leads to loss of chlorophyll, increased membrane damage and progressive decline in photosynthetic capacity (Djanaguiraman et al, 2009). High temperature stress directly damages the photosynthetic apparatus and decreases both photosynthetic rate and duration of the assimilate supply (Prasad et al, 2008; (Srivalli and Khanna-Chopra, 2004).…”

“…Selenium (Se) can prevent oxidative damage to body tissues (Lobanov et al, 2008) because of its structural role in synthesis of glutathione peroxidase enzyme. Se can also increase tolerance of plants exposed to low temperature (Hawrylak-Nowak et al, 2010), drought stress (Valadabadi et al, 2010) and aluminum toxicity (Cartes et al, 2010). Djanaguiraman et al (2005) …”

Modulation of Antioxidant Machinery and the Methylglyoxal Detoxification System in Selenium-Supplemented Brassica napus Seedlings Confers Tolerance to High Temperature Stress

“…For the past couple of decades, the beneficial role of Se in plants has been reported, but the question is still unresolved whether Se is an essential micronutrient for plants. Some plant species supplemented with Se have also shown enhanced tolerance to certain abiotic stresses like salinity [15,16], drought [17], extreme temperature [18,19], metal toxicity [20,21], and UV radiation [22]. There is evidence for the role of Se in enhancing the cellular antioxidant machineries in plants which resulted in the detoxification of ROS [23].…”