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Glucose is recognized as signaling molecule that regulates growth and development of plants under various environmental cues, but their effect in regulation of copper induced toxicity in plants is not yet investigated. This study revealed the effect of exogenously sourced glucose on Cucumber plants exposed to increasing concentration of copper. Glucose mediated response on growth performance, photosynthetic efficiency, antioxidant enzymes, oxidative stress markers, ion uptake were analyzed in the presence and absence of copper. Glucose alone and in combination with lower concentration of copper improved the growth, photosynthetic performance, and antioxidant capacity of cucumber plants. However, higher concentrations of copper alone showed oxidative damage through increased electrolyte leakage, H 2 O 2 accumulation, lipid peroxidation and reduced uptake of macronutrients. Application of glucose to copper-stressed plants enhanced activities of Rubisco, antioxidant enzymes, proline accumulation and maintained copper level in aerial parts of plants. These enhanced activities of antioxidant enzymes, proline accumulation, uptake of NPK and maintained equilibrium of copper in plants, leading to detoxification of copper stress in cucumber plants. This study provides an understanding that exogenous application of glucose can be employed as vital biochemical approach in alleviating copper-induced toxicity and could be utilized as phytoremediation technique for removal of excess transition metal from polluted soil., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

24-Epibrassinolide (EBL) and Selenium (Se) individually confer tolerance to various abiotic stresses, but their interactive effect in the regulation of copper (Cu) homeostasis in plants exposed to toxic levels of Cu is poorly investigated. This study provides an insight into the effects of EBL (foliar) and/or Se (through sand) on Brassica juncea plants exposed to toxic levels of Cu. The combined effect of EBL and Se on compartmentalization of Cu, oxidative stress markers, photosynthetic machinery and biochemical traits in B. juncea were analyzed. Application of EBL and Se through different mode modulated the compartmentalization of Cu in different parts of plants, enhanced the photosynthetic traits, and activities of various antioxidant enzymes and proline accumulation in B. juncea under excess copper levels. These enhanced levels of antioxidant enzymes, proline (osmolyte) accumulation triggered by combination of EBL and Se could have conferred tolerance to the B. juncea plants under toxic level of copper and also maintained Cu homeostasis in various parts of plants. This study indicates that combination of EBL and Se through different mode is an operative approach for Cu detoxification in plants and could be exploited for removal of excess copper from polluted soil., (Copyright © 2016. Published by Elsevier Inc.)

• Allelopathic effects of the aqueous extract of the Alhagi maurorum was investigated. • Aqueous extract of the Alhagi maurorum mediated inhibition was concentration- and species- dependent. • The phytochemical analyses revealed that the presence of several phenolic compounds. • These natural products could be used as "eco-friendly" bio-herbicides for weed control. The present work was conducted to evaluate the effect of aqueous extract of Alhagi maurorum at different rates (1, 5, 10, 15%, w/v) on the growth as well as some physiological parameters of pea (Pisum sativum L.). The pot experiment revealed that Alhagi maurorum aqueous extract reduced all growth parameters of pea plant along with photosynthesis pigments, insoluble sugars, total carbohydrate, total protein and total phenolics. On the other hand, soluble sugars, soluble protein, proline, flavonoids and antioxidant enzymes increased upon treatment with aqueous solution of Alhagi maurorum. The adverse effect of the extract on the growth of treated pea plants especially hydroquinone and sinapyl alcohol that were found in relatively high concentration in the extract were identified and quantified by the GC–MS of the methanolic extract of Alhagi maurorum. [ABSTRACT FROM AUTHOR]

Low temperature can delay growth and development, reduce productivity, or cause plant death. An experiment was carried out to determine the most sensitive and most tolerant tomato (Solanum lycopersicumL.; variety S-22, Selection N-5, Pusa Gorav, K-21, Pusa Ruby, Hera Research, and PKM-1) to low temperature. Forty-day-old seedlings were exposed to day/night temperatures of 10/3°C, 12/7°C, 20/14°C, or 25/18°C (control) for 24 h in a plant growth chamber and then transferred to ambient environmental conditions in a net house and maintained for 60 days. Decreasing temperature led to decreases in growth, chlorophyll content, and photosynthesis rate in all varieties. Activity of antioxidant enzymes catalase, peroxidase, and superoxide dismutase and proline accumulation in leaves increased in all varieties as temperature decreased. Variety S-22 had the most antioxidant enzyme activity and proline accumulation and ‘PKM-1’ had the lowest antioxidant enzyme activity and proline content; these were classified as tolerant and sensitive, respectively. Tolerant tomato varieties provide options for producers where low temperature can interfere with plant development. [ABSTRACT FROM PUBLISHER]

Introduction: This study was hypothesized that salicylic acid elevates the level of antioxidant system that will protect plants from the stress generated by nickel and/or salinity. Materials and methods: Seeds of Brassica juncea were sown in sand amended with NiCl (100 mg kg) and/or 15-day-old seedlings supplied for 3 days with NaCl (150 mM) and were then, at 20-day stage, sprayed with salicylic acid (10 M) to assess selected morphological, physiological, and biochemical parameters at 30-day stage. Results: The combination of Ni and NaCl proved most deleterious and exhibited significant decline in growth, leaf water potential, the level of pigments, and photosynthetic attributes. However, the follow-up treatment with salicylic acid detoxified the stress-generated damages caused by the combination (NiCl and NaCl) and also significantly improved values for the above parameters. The NiCl and/or NaCl increased electrolyte leakage, lipid peroxidation, and HO content but decreased the membrane stability index and activity of nitrate reductase and carbonic anhydrase. However, the salicylic acid treatment in the presence or absence of the stress improved the activity of nitrate reductase and carbonic anhydrase. The activity of antioxidative enzymes and the level of proline exhibited a significant increase in response to NiCl and/or NaCl stress and which enhanced further with the spray of salicylic acid. Conclusions: It is concluded that the elevated level of antioxidative enzymes and level of proline might be responsible for minimizing the Ni and/or salinity-induced toxicity in Indian mustard which is manifested in terms of improved growth and photosynthesis. [ABSTRACT FROM AUTHOR]

Seeds of five wheat ( Triticum aestivum) cultivars (PBW-373, UP-2338, DL-LOK-01, DL-373, and HD-2338) were sown in earthen pots and 10-day-old seedlings were exposed to 0, 50, and 100 μM of nickel (Ni) in the form of nickel chloride. At the 20-day stage, seedlings were sprayed with 0.01 μM of 28-homobrassinolide (HBL). The results of the experiment at the 30-day stage revealed a decline in the dry mass per plant, leaf area, leaf water potential, and net photosynthetic rate with concomitant decline in the activities of various enzymes (viz . carbonic anhydrase and nitrate reductase) with an increasing concentration of Ni. However, an increase in proline content and the activities of catalase, peroxidase, and superoxide dismutase was observed as a result of an increase in Ni concentration. Moreover, the treatment of these stressed plants with HBL enhanced the activities of carbonic anhydrase and nitrate reductase, catalase, peroxidase, and superoxide dismutase. The proline content in the leaves also increased, which is known to act as an osmolyte and reactive oxygen species scavenger. The toxic effects generated by Ni were ameliorated by HBL through an improved antioxidant system and osmolyte. Moreover, improvement of photosynthetic parameters and growth characteristics further strengthen our belief that HBL acted as a potent stress alleviator. [ABSTRACT FROM AUTHOR]

This study was designed to assess the combined effect of both aluminium and salt stress on the processes and molecules pertinent to these stresses and to establish relationship between these two stresses on the basis of photosynthetic attributes and antioxidant enzymes in wheat cultivars. Seven different varieties of wheat grown under environmentally controlled conditions. At 10 days stage of growth, plants were treated with NaCl (100 or 150 mM) and/or Al (05 or 10 mM) through soil. At 30 days stage, treatment of Al and salt stress alone showed the similar deteriorating response in terms of photosynthetic traits and LWP whereas, electrolyte leakage, lipid peroxidation, H2O2content along with enzymes of antioxidant and proline content varied in different varieties of wheat. Moreover, the combination of Al and salt stress further increased the antioxidant enzymes and proline accumulation. However, salt stress restrict the uptake of Al by roots in significant manner under combine treatment of Al and salt stress. The pattern of tolerance was observed on the basis of enhanced antioxidant system and proline accumulation and cultivar LOK-1 and 502 showed maximum and minimum tolerance respectively against the combination of salt and aluminium stress. [ABSTRACT FROM AUTHOR]