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The emergence of polyvinyl chloride (PVC) microplastics (MPs) as pollutants in agricultural soils is increasingly alarming, presenting significant toxic threats to soil ecosystems. Ajwain (Trachyspermum ammi L.), a plant of significant medicinal and culinary value, is increasingly subjected to environmental stressors that threaten its growth and productivity. This situation is particularly acute given the well-documented toxicity of chromium (Cr), which has been shown to adversely affect plant biomass and escalate risks to the productivity of such economically and therapeutically important species. The present study was conducted to investigate the individual effects of different levels of PVC-MPs (0, 2, and 4 mg L -1 ) and Cr (0, 150, and 300 mg kg -1 ) on various aspects of plant growth. Specifically, we examined growth and biomass, photosynthetic pigments, gas exchange attributes, oxidative stress responses, antioxidant compound activity (both enzymatic and nonenzymatic), gene expression, sugar content, nutritional status, organic acid exudation, and Cr accumulation in different parts of Ajwain (Trachyspermum ammi L.) seedlings, which were also exposed to varying levels of titanium dioxide (TiO 2 ) nanoparticles (NPs) (0, 25, and 50 µg mL -1 ). Results from the present study showed that the increasing levels of Cr and PVC-MPs in soils significantly decreased plant growth and biomass, photosynthetic pigments, gas exchange attributes, sugars, and nutritional contents from the roots and shoots of the plants. Conversely, increasing levels of Cr and PVC-MPs in the soil increased oxidative stress indicators in term of malondialdehyde, hydrogen peroxide, and electrolyte leakage, and also increased organic acid exudation pattern in the roots of T. ammi seedlings. Interestingly, the application of TiO 2 -NPs counteracted the toxicity of Cr and PVC-MPs in T. ammi seedlings, leading to greater growth and biomass. This protective effect is facilitated by the NPs' ability to sequester reactive oxygen species, thereby reducing oxidative stress and lowering Cr concentrations in both the roots and shoots of the plants. Our research findings indicated that the application of TiO 2 -NPs has been shown to enhance the resilience of T. ammi seedlings to Cr and PVC-MPs toxicity, leading to not only improved biomass but also a healthier physiological state of the plants. This was demonstrated by a more balanced exudation of organic acids, which is a critical response mechanism to metal stress., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Wheat (Triticum aestivum L.) is among the plants that are at risk from cadmium (Cd), a hazardous heavy metal that can be fatal due to its rapid absorption and high mobility. Being taken up from the soil and moving to the shoots and roots of edible plants, it enters the food chain and poses a health concern to people worldwide. A strategically important cereal crop, wheat has a demonstrated role in human health systems, particularly in poor nations. In this study, we describe the effects of nitric oxide (NO) on the growth, nutrition, and physiological functions of commercially cultivated wheat cvs. Galaxy 2013 and Akbar 2019 under Cd stress. Four-week-old plants were subjected to Cd (0.5 mM) stress, and after 2 weeks of Cd toxicity, foliar application of nitric oxide (100 and 150 μM) was carried out. As evident from excessive antioxidant production, Cd toxicity increased reactive oxygen species (ROS) level like H 2 O 2 and significantly (p ≤ 0.001) decreased nutrient acquisition, growth, and yield attributes of plants under experiment. The severity of the effect varied between cultivars under investigation. A minimum accumulation of MDA (44%) and H 2 O 2 (55%) was found in the cv. Akbar 2019 under Cd stress, whilst cv. Galaxy 2013 showed the highest accumulation of the oxidative stress indicators malondialdehyde content (MDA) (48%) and H 2 O 2 (60%). Reduced and oxidized glutathione contents were also increased under Cd-induced toxicity. The application of NO resulted in a significant improvement of 22, 25, 25, and 30% in shoot fresh weight, root fresh weight, shoot dry weight, and root dry weight, respectively. Additionally, there was an increased uptake of Ca +2 (16%), K +1 (5%), chlorophyll a (46%), b (32%), a/b ratio (41%), and carotenoid (28%). When compared with Cd-stressed plants, yield parameters like 100 grain weight, number of tillers plant -1 , and grain yield plant -1 improved by 14, 17, and 33%, respectively, under NO application. We concluded from the results of this study that NO treatments increased plant development by lowering oxidative stress and limiting Cd uptake. It is inferred from the results of this study that wheat production with reduced heavy metal uptake may be facilitated using NO due to its cytoprotective properties and its interaction with ROS., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cadmium significantly impacts plant growth and productivity by disrupting physiological, biochemical, and oxidative defenses, leading to severe damage. The application of Zn-Lys improves plant growth while reducing the stress caused by heavy metals on plants. By focusing on cadmium stress and potential of Zn-Lys on pea, we conducted a pot-based study, organized under completely randomized block design CRD-factorial at the Botanical Garden of Government College University, Faisalabad. Both pea cultivars were grown in several concentrations of cadmium @ 0, 50 and 100 μM, and Zn-Lys were exogenously applied @ 0 mg/L and 10 mg/L with three replicates for each treatment. Cd-toxicity potentially reduces plant growth, chlorophyll contents, osmoprotectants, and anthocyanin content; however, an increase in MDA, H 2 O 2 initiation, enzymatic antioxidant activities as well as phenolic, flavonoid, proline was observed. Remarkably, exogenously applied Zn-Lys significantly enhanced the plant growth, biomass, photosynthetic attributes, osmoprotectants, and anthocyanin contents, while further increase in enzymatic antioxidant activities, total phenolic, flavonoid, and proline contents were noticed. However, application of Zn-Lys instigated a remarkable decrease in levels of MDA and H 2 O 2 . It can be suggested with recommendation to check the potential of Zn-Lys on plants under cadmium-based toxic soil., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In the current industrial scenario, cadmium (Cd) as a metal is of great importance but poses a major threat to the ecosystem. However, the role of micronutrient - amino chelates such as iron - lysine (Fe - lys) in reducing Cr toxicity in crop plants was recently introduced. In the current experiment, the exogenous applications of Fe - lys i.e., 0 and10 mg L - 1, were examined, using an in vivo approach that involved plant growth and biomass, photosynthetic pigments, oxidative stress indicators and antioxidant response, sugar and osmolytes under the soil contaminated with varying levels of Cd i.e., 0, 50 and 100 µM using two different varieties of canola i.e., Sarbaz and Pea - 09. Results revealed that the increasing levels of Cd in the soil decreased plant growth and growth-related attributes and photosynthetic apparatus and also the soluble protein and soluble sugar. In contrast, the addition of different levels of Cd in the soil significantly increased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), which induced oxidative damage in both varieties of canola i.e., Sarbaz and Pea - 09. However, canola plants increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and non-enzymatic compounds such as phenolic, flavonoid, proline, and anthocyanin, which scavenge the over-production of reactive oxygen species (ROS). Cd toxicity can be overcome by the supplementation of Fe - lys, which significantly increased plant growth and biomass, improved photosynthetic machinery and sugar contents, and increased the activities of different antioxidative enzymes, even in the plants grown under different levels of Cd in the soil. Research findings, therefore, suggested that the Fe - lys application can ameliorate Cd toxicity in canola and result in improved plant growth and composition under metal stress., (© 2023. The Author(s).)

Both cadmium (Cd) toxicity and water limited stress in crop plants are serious concerns worldwide while little is known about the impact of various phosphorus (P) sources on Cd accumulation in cereals especially under water limited stress. A study was conducted to explore the efficiency of three frequently available P fertilizers on Cd accumulation in wheat under different soil moisture levels. Three different P sources including diammonium phosphate (DAP), single super phosphate (SSP), and nitrophos (NP) were applied in the soil with three levels (0, 50 and 100 mg/kg). The drought stress was applied to half treatments during the latter growth stages of wheat and plants were harvested at maturity. The results demonstrated that water-limited stress decreased the growth and yield of plants than respective treatments without water stress. P supply increased the growth of wheat irrespective of water-limited stress. The effect on growth and yield varied with the sources and levels of P and maximum effects was observed in DAP treatment (100 mg/kg). The P amendments enhanced the leaf photosynthesis and activities of SOD, POD, CAT and decreased the leaf oxidative burst. Water limited stress enhanced the Cd concentrations in shoots, roots, and grains whereas P amendments minimized the Cd concentrations and enhanced the P concentrations in these parts of plants. The results obtained demonstrated that P supply in the form of DAP might be effective in minimization of Cd in grains and can be used for safe cultivation of metal-contaminated soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Soil contamination with cadmium (Cd) is a persistent threat to crop production worldwide. The present study examined the putative roles of nitric oxide (NO) in improving Cd-tolerance in cauliflower (Brassica oleracea L.). The present study was conducted using four different genotypes of B. oleracea named as FD-3, FD-4, FD-2 and Ceilo Blanco which were subjected to the Cd stress at various concentrations i.e., 0, 5, 10 and 20 µM with or without the application of NO i.e., 0.10 mM in the sand containing nutrient Hoagland's solution. Our results illustrated that the increasing levels of Cd in the sand, significantly (P < 0.05) decreased shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, germination percentage, germination index, mean germination time, time to 50% germination, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents in all genotypes of B. oleracea. The concentration of malondialdehyde (MDA) and Cd accumulation (roots and shoots) increased significantly (P < 0.05) under the increasing levels of Cd in all genotypes of B. oleracea while antioxidant (enzymatic or non-enzymatic) capacity and nutritional status of the plants was decreased with varying levels of Cd in the sand. From all studied genotypes of B. oleracea, Ceilo Blanco and FD-4 was found to be most sensitive species to the Cd stress under the same levels of the Cd in the medium while FD-2 and FD-3 showed more tolerance to the Cd stress compared to all other genotypes of B. oleracea. Although, toxic effect of Cd in the sand can overcome by the application of NO which not only increased plant growth and nutrients accumulation but also decreased the oxidative damage to the membranous bounded organelles and also Cd accumulation in various parts of the plants in all genotypes of B. oleracea. Hence, it was concluded that application of NO can overcome Cd toxicity in B. oleracea by maintaining the growth regulation and nutritional status of the plant and overcome oxidative damage induced by Cd toxicity in all genotypes of B. oleracea., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Phytoremediation is an ecofriendly technique to clean heavy metals from contaminated soil by the use of high biomass producing plant species. Chelators can help to improve this biological technique by increasing metal solubility. Therefore, a pot experiment was conducted to determine the effect of the chelators EDTA and citric acid (CA) in phytoremediation of Ni contaminated soil by using Brassica napus (canola). Two cultivars of B. napus, Con-II (tolerant) and Oscar (sensitive), were selected after screening and exposed to NiSO4 at 30 ppm at the time of sowing. CA (10 mM) and EDTA (1.5 mM) were applied either alone or in combination with each other after two weeks of Ni treatments. Different parameters like morpho-physiological and biochemical data were recorded after 15 days of chelate application. The results highlighted the successful use of chelating agents (CA and EDTA) not only to ameliorate Ni stress but also to enhance Ni accumulation which is prerequisite for phytoremediation. The basal application of 10 mMCA and 1.5 mM EDTA concentration proved to be effective for the growth of plants. The combination of chelating agents failed to show any synergistic effects.

Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to the rapid development of the social economy. This study was carried out to assess the beneficial role of two different kinds of (S)-fertilizer in the phytoremediation of Cd contaminated soil through Solanum nigrum L. Gypsum (Gyp) and Elemental sulfur (ES) was applied alone and in combination with different ratios (0, 100:0, 0:100, 50:50 mg kg -1 ) accompanied by different Cd levels (0, 25, 50 mg kg -1 ). After seventy days of sowing, plants were harvested for determination of growth, physiological characteristics, oxidants and antioxidants, along with Cd uptake from different parts of the plant. Cd toxicity significantly inhibited growth, physiology and plant defence systems, and also increased Cd uptake in the roots and shoots of Solanum nigrum L. The application of Gyp 100 mg kg -1 boosted plant growth and physiology along with oxidants and antioxidants activity as compared to ES 100 mg kg -1 alone, and combine application of GYP+ES 50 + 50 mg kg -1 . The application of ES 100 mg kg -1 showed an effective approach to decreasing Cd uptake as compared to Gyp 100 mg kg -1 . Overall results showed that the combined application of GYP+ES 50 + 50 mg kg -1 significantly enhanced the phytoremediation potential of S. nigrum in Cd contaminated soil. Thus, it is highly recommended to apply the combined application of GYP+ES for phytoremediation of Cd contaminated soil.

It was aimed to examine the role of gibberellic acid (GA 3 ) and NPK fertilizer in alleviating boron (B) toxicity in coriander (Coriandrum sativum L.) plants. Two weeks old C. sativum seedlings were subjected to different NPK fertilizers [low NPK (30 kg ha -1 ) and normal NPK (60 kg ha -1 )], which were also supplied by GA 3 (50 mg L -1 ), under varying levels of B i.e., 0, 200 and 400 mg kg -1 in the soil. Results revealed that B toxicity led to a substantial decreased in the plant growth and biomass, photosynthetic pigments, gas exchange characteristics, sugars and essential nutrients in the roots and shoots of C. sativum seedlings. However, B toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in C. sativum seedlings and was also manifested by hydrogen peroxide (H 2 O 2 ) contents and electrolyte leakage (EL) to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), non-enzymatic antioxidants like phenolic, flavonoid, ascorbic acid and anthocyanin contents and organic acids from the roots such as oxalic acid, malic acid, formic acid, citric acid, acetic acid and fumaric acid contents were increased with the increasing levels of B in the soil. The application if NPK and GA 3 mitigated B toxicity by stimulated plant growth and biomass, photosynthetic efficiency, nutritional status and antioxidant machinery of the plant by decreasing MDA contents, H 2 O 2 initiation and EL (%) in the roots and leaves of C. sativum seedlings. In addition, the application of NPK and GA 3 further decreased the organic acids exudation contents in the roots C. sativum seedlings. Research findings, therefore, suggested that NPK and GA 3 application can ameliorate B toxicity in C. sativum seedlings and resulted in improved plant growth and composition under B stress as depicted by balanced contents of organic acids., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Chromium (Cr), being a persistent toxic heavy metal, triggered the retardation of plant's metabolic processes by initiating changes in rhizospheric zone. Current study focused the Cr accumulation potential of two tomato (Solanum lycopersicum Mill.) cultivars through alterations of rhizospheric pH and exudation of organic acids together with plant's ionomics and morpho-physiological responses. Four-week-old seedlings of tomato cultivars (cv. Nakeb and cv. Nadir) were maintained in hydroponic solutions supplemented with 0, 100, 200, and 300 mg/L K 2 Cr 2 O 7 and a start pH of 6.0. The pH of the growth medium was monitored twice a day up to 6 days as well as mineral contents and morpho-physiological attributes were recorded by harvesting half of plants after 1 week. The remaining half plants were shifted to rhizoboxes for the collection of root exudates. After 6 days, cv. Nakeb exhibited medium acidification by 0.7 units while cv. Nadir showed basification by 0.6 units under 300 mg/L treatment. Increase in applied Cr levels enhanced the root and shoot Cr accumulation in both cultivars with concomitant reduction in growth and accumulation of nutrients (Fe, Zn, K, Mg, and Ca). However, this reduction in biomass and nutrient acquisition was predominant in cv. Nakeb as compared to cv. Nadir. The release of organic acid exudates (citric, acetic, maleic, tartaric, and oxalic acids) was also recorded higher in cv. Nadir at 300 mg/L applied Cr level. This enhanced production of organic acids caused greater retention of mineral nutrients and Cr in cv. Nadir, probably due to growth medium basification. Enhanced exudations of di- and tri- carboxylic organic acids together with accumulation of mineral nutrients are the physiological and biochemical indicators which confer this genotype a better adaptation to Cr polluted biotic systems. Furthermore, it was perceived that organic acid and rhizospheric pH variation response by studied tomato cultivars under Cr stress is an important factor to be considered in food safety and metal remediation programs.

Copper (Cu) pollution in agricultural soils is considered as a serious health risk due to its accumulation in plants. Thus, there is an urgent need to optimize nutrient application for higher yield with lower Cu uptake to ensure food security. A pot experiment was conducted to investigate the effectiveness of nitrogen fertilizer (N) on Boehmeria nivea growth, gas exchange characteristics, antioxidant capacity and uptake of Cu in contaminated soil. Therefore, combinations of Cu levels (0, 100, 300 mg kg -1 ) and N levels (0, 140, 280, 420 kg ha -1 ) were applied. The results showed that N at 280 kg ha -1 significantly (≤0.05) increased plant growth in terms of fresh biomass, plant height, stem diameter and number of leaves per plant up to100 mg kg -1 Cu in soil for all harvests (H 1 , H 2 , H 3 and H 4 ). However, the interactive effect of Cu and N on Cu uptake by plant varied among N levels. Furthermore, N at 280 kg ha -1 also improved the gas exchange characteristics viz., net photosynthesis (Pn), transpiration rate (Tr) and stomatal conductance (gs), while decreased oxidative stress in B. nivea up to 100 mg kg -1 Cu in soil, relative to control. Thus N at 280 kg ha -1 can be considered as an effective dose for high fresh biomass with lower Cu uptake by B. nivea grown as fodder in Cu contaminated soils (≤100 mg kg -1 ). Overall, present research highlighted the necessity of balanced or optimum N application for sustainable B. nivea forage production in Cu contaminated agricultural lands., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to rapid development of social economy. Silicon (Si), being an important fertilizer element, has been found effective in enhancing plant tolerance against biotic and abiotic stresses. The present study investigated the extent to which different levels of Si modulated the Cd tolerance of Ajwain (Trachyspermum ammi L.) seedlings when maintained in artificially Cd spiked regimes. A pot experiment was conducted under controlled conditions for four weeks, by using sand, mixed with different levels of Cd i.e., 0, 1.5 and 3 mM together with the application of Si at 0, 1.5 and 3 mM levels to monitor different growth, gaseous exchange, oxidative stress, antioxidative responses, minerals accumulation, organic acid exudation patterns of T. ammi seedlings. Our results depicted that Cd addition to growth medium significantly decreased plant growth and biomass, gaseous exchange attributes and minerals uptake by T. ammi seedlings as compared to the plants grown without addition of Cd. However, Cd toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in T. ammi seedlings and was also manifested by hydrogen peroxide (H 2 O 2 ) contents and electrolyte leakage to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) initially increased up to a Cd level of 1.5 mM but were significantly diminished at the highest Cd level of 3 mM. Results revealed that the anthocyanin and soluble proteins contents were decreased in seedlings grown under elevating Cd levels but increased the Cd accumulation of T. ammi roots and shoots. The negative impacts of Cd injury were reduced by the application of Si which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, minerals uptake together with diminished exudation of organic acids as well as oxidative stress indicators in roots and shoots of T. ammi by decreasing Cd retention in different plant parts. Research findings, therefore, suggested that Si application can ameliorate Cd toxicity in T. ammi seedlings and resulted in improved plant growth and composition under metal stress as depicted by balanced exudation of organic acids., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Copper (Cu) is an abundant essential micronutrient element in various rocks and minerals and is required for a variety of metabolic processes in both prokaryotes and eukaryotes. However, excess Cu can disturb normal development by adversely affecting biochemical reactions and physiological processes in plants. The present study was conducted to explore the potential of gibberellic acid (GA 3 ) on fibrous jute (Corchorus capsularis L.) seedlings grown on Cu mining soil obtained from Hubei Province China. Exogenous application of GA 3 (10, 50, and 100 mg/L) on 60-day-old seedlings of C. capsularis which was able to grow in highly Cu-contaminated soil (2221 mg/kg) to study different morphological, physiological, and Cu uptake and accumulation in different parts of C. capsularis seedlings. According to the results, increasing concentration of GA 3 (more likely 100 mg/L) alleviates Cu toxicity in C. capsularis seedlings by increasing plant growth, biomass, photosynthetic pigments, and gaseous exchange attributes. The results also showed that exogenous application of GA 3 reduced oxidative stress in C. capsularis seedlings by the generation of extra reactive oxygen species (ROS). The reduction in oxidative stress in C. capsularis seedlings is because that plant has strong enzymatic antioxidants [superoxidase dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT)], which ultimately increased their activities to overcome oxidative damage in the cells/tissues. In addition to the plant growth, biomass, and photosynthesis, foliar application of GA 3 also helps to increase metal (Cu) concentration in different parts of the plants when compared to 0 mg/L of application of GA 3 . From these findings, we can conclude that foliar application of GA 3 plays a promising role in reducing ROS generation in the plant cells/tissues and increased phytoextraction of Cu in different plant parts. However, more investigation is needed on field experiments to find a combination of GA 3 with a very higher concentration of Cu using fibrous C. capsularis.

Copper (Cu), with many documented cases of Cu toxicity in agriculture lands, is becoming an increasingly common issue in and elsewhere in China. However, fibrous crop such as jute is being used as phytoremediation candidate in Cu-contaminated soils due to its huge biomass. A pot experiment was conducted using four different varieties (HT, C-3, GC, and SH) of jute grown in highly Cu-contaminated soil (2221 mg kg -1 ), collected from Hubei Province, China. Results from this study showed that C-3 and HT were more resistant to Cu stress, while GC and SH had a serious effect due to high concentration of Cu and a significant decrease in growth and biomass. Furthermore, Cu in roots, leaves, stem core, and bast were higher in C-3 and HT compared with GC and SH. Likewise, at post-harvesting stage, maximum Cu concentration from Cu-contaminated soil was extracted by C-3 and HT while small amount was accumulated by GC and SH. The high content of malondialdehyde (MDA) in the leaves of GC and SH indicated that Cu induced oxidative damage while the antioxidative enzyme activities of superoxidase dismutase (SOD) and peroxidase (POD) were increased to scavenge reactive oxygen species (ROS) formed during oxidative stress in the plants. Conclusively, it can be identified that when grown in Cu-contaminated soil, C-3 and HT have greater ability to grow in polluted soils and possible phytoremediation materials to revoke a large amount of Cu.

Soil in mining areas is typically highly contaminated with heavy metals and lack essential nutrients for plants. Phosphorus reduces oxidative stress, improves plant growth, composition, and cellular structure, as well as facilitates the phytoremediation potential of fibrous crop plant species. In this study, we investigated two jute (Corchorus capsularis) varieties HongTieGuXuan and GuBaChangJia cultivated in copper (Cu)-contaminated soil (2221 mg kg -1 ), under different applications of phosphorus (0, 30, 60, and 120 kg ha -1 ) at both anatomical and physiological levels. At the same Cu concentration, the tolerance index of HongTieGuXuan was higher than that of GuBaChangJia, indicating that HongTieGuXuan may be more tolerant to Cu stress. Although the normal concentration of P (60 kg ha -1 ) in the soil improved plant growth, biomass, chlorophyll content, fibre yield and quality, and gaseous exchange attributes. However, high concentration of P (120 kg ha -1 ) was toxic to both jute varieties affected morphological and physiological attributes of the plants under same level of Cu. Moreover, Cu toxicity increased the oxidative stress in the leaves of both jute varieties was overcome by the activities of antioxidant enzymes. Furthermore, the high concentration of Cu altered the ultrastructure of chloroplasts, plastoglobuli, mitochondria, and many other cellular organelles in both jute varieties. Thus, phytoextraction of Cu by both jute varieties increased with the increase in P application in the Cu-contaminated soil. This suggests that P application enhanced the phytoremediation potential jute plants and can be cultivated as fibrous crop in Cu-contaminated sites., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Flax (Linum usitatissimum L.) is one of the oldest predominant industrial crops grown for seed, oil and fiber. The present study was executed to evaluate the morpho-physiological traits, biochemical responses, gas exchange parameters and phytoextraction potential of flax raised in differentially copper (Cu) spiked soil viz (0, 200, 400 and 600 mg Cu kg -1 soil) under greenhouse pot experiment. The results revealed that flax plants were able to grow up to 400 mg kg -1 Cu level without showing significant growth inhabitation while, further inference of Cu (600 mg kg -1 ) in the soil prominently inhibited flax growth and biomass accumulation. Compared to the control, contents of proline and malondialdehyde (MDA) were increased by 160.0% and 754.1% accordingly, at 600 mg Cu kg -1 soil level. The Cu-induced oxidative stress was minimized by the enhanced activities of superoxide dismutase (SOD) by 189.2% and guaiacol peroxidase (POD) by 300.8% in the leaves of flax at 600 mg Cu kg -1 soil level, compared to the untreated control. The plant Cu concentration was determined at 35, 70, 105 and 140 days after sowing (DAS) and results depicted that 16.9 times higher Cu concentration was accumulated in flax roots while little (14.9 times) was transported to the shoots at early stage of growth, i.e. 35 DAS. While at 140 DAS, Cu was highly (21.7 times) transported to the shoots while, only 12.3 times Cu was accumulated in the roots at 600 mg Cu kg -1 soil level, compared to control. Meanwhile, Cu uptake by flax was boosted up to 253 mg kg -1 from the soil and thereby extracted 43%, 39% and 41% of Cu at 200, 400 and 600 mg Cu kg -1 soil level, compared to initial Cu concentration. Therefore, study concluded that flax has a great potential to accumulate high concentration of Cu in its shoots and can be utilized as phytoremediation material when grown in Cu contaminated soils., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Jute (Corchorus capsularis L.) is the most commonly used natural fiber as reinforcement in green composites and, due to its huge biomass, deep rooting system, and metal tolerance in stressed environments, it is an excellent candidate for the phytoremediation of different heavy metals. Therefore, the present study was carried out to examine the growth, antioxidant capacity, gaseous exchange attributes, and phytoremediation potential of C. capsularis grown at different concentrations of Cu (0, 100, 200, 300, and 400 mg kg -1 ) in a glass house environment. The results illustrate that C. capsularis can tolerate Cu concentrations of up to 300 mg kg -1 without significant decreases in growth or biomass, but further increases in Cu concentration (i.e., 400 mg kg -1 ) lead to significant reductions in plant growth and biomass. The photosynthetic pigments and gaseous exchange attributes in the leaves of C. capsularis decreased as the Cu concentration in the soil increased. Furthermore, high concentrations of Cu in the soil caused lipid peroxidation by increasing the malondialdehyde content in the leaves. This implies that elevated Cu levels cause oxidative damage in C. capsularis. Antioxidants, such as superoxidase dismutase and peroxidase, come into play to scavenge the reactive oxygen species which are generated as a result of oxidative stress. In the present study, the concentrations of Cu in different parts of the plant (the roots, leaves, stem core, and fibers) were also investigated at four different stages of the life cycle of C. capsularis, i.e., 30, 60, 90, and 120 days after sowing (DAS). The results of this investigation reveal that, in the earlier stages of the growth, Cu was highly accumulated in the belowground parts of the plant while little was transported to the aboveground parts. Contrastingly, at a fully mature stage of the growth (120 DAS), it was observed that the majority of Cu was transported to the aboveground parts of the plant and very little accumulated in the belowground parts. The results also show a progressive increase in Cu uptake in response to increasing Cu concentrations in the soil, suggesting that C. capsularis is a potential bio-resource for the phytoremediation of Cu in Cu-contaminated soil., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Flax (Linum usitatissimum L.), one of the oldest cultivated crops, continues to be widely grown for oil, fiber and food. Furthermore, the plants show a metal tolerance dependent on species so is ideal for research. Present study was conducted to find out the influence of copper (Cu) toxicity on plant biomass, growth, chlorophyll content, malondialdehyde (MDA) contents, proline production, antioxidative enzymes and metal up taken by L. usitatissimum from the soil grown under mixing of Cu-contaminated soil with natural soil by 0:1 (control), 1:0, 1:1, 1:2 and 1:4. Results revealed that, high concentration of Cu in the soil affected plant growth and development by reducing plant height, plant diameter and plant fresh and dry biomass and chlorophyll contents in the leaves compared with the control. Furthermore, Cu in excess causes generation of reactive oxygen species (ROS) such as superoxide radical (O - ) and hydroxyl radicals (OH), which is manifested by high malondialdehyde (MDA) and proline contents also. The increasing activities of superoxidase dismutase (SOD) and peroxidase (POD) in the roots and leaves of L. usitatissimum are involved in the scavenging of ROS. Results also showed that L. usitatissimum also has capability to revoke large amount of Cu from the contaminated soil. As Cu concentration in the soil increases, the final uptake of Cu concentration by L. usitatissimum increases. Furthermore, the soil chemical parameters (pH, electrical conductivity and cation exchange capacity) were increasing to highest levels as the ratio of Cu concentration to the natural soil increases. Thus, Cu-contaminated soil is amended with the addition of natural soil significantly reduced plant growth and biomass, while L. usitatissimum is able to revoke large amount of Cu from the soil and could be grown as flaxseed and a potential candidate for phytoremediation of Cu.

Copper (Cu) is one of the micronutrients needed by living organisms. In plants, Cu plays key roles in chlorophyll formation, photosynthesis, respiratory electron transport chains, oxidative stress protection as well as protein, carbohydrate, and cell wall metabolism. Therefore, deficiency of Cu can alter various functions of plant metabolism. However, Cu-based agrochemicals have traditionally been used in agriculture and being excessively released into the environment by anthropogenic activities. Continuous and extensive release of Cu is an imperative issue with various documented cases of phytotoxicity by the overproduction of reactive oxygen species (ROS) and damage to carbohydrates, lipids, proteins, and DNA. The mobility of Cu from soil to plant tissues has several concerns including its adverse effects on humans. In this review, we have described about importance and occurrence of Cu in environment, Cu homeostasis and toxicity in plants as well as remediation and progress in research so far done worldwide in the light of previous findings. Furthermore, present review provides a comprehensive ecological risk assessment on Cu in soils and thus provides insights for agricultural soil management and protection.

Copper (Cu) contamination in agricultural soil poses severe threats to living organisms, and possible ecofriendly solutions need to be considered for Cu immobilization, such as using biochar. A pot study was conducted to examine the effectiveness of biochar derived from rice straw (RSB) at various application rates (0, 2.5, 5 and 10% w/w) to mitigate possible risks of Cu solubility and its uptake by ramie (Boehmeria nivea L.) as forage. The plant growth parameters as well as soil chemical properties (pH, electrical conductivity and cation exchange capacity) notably improved with the increasing RSB application. Moreover, prominent reduction was observed in soil bioavailable Cu concentration by 96% with RSB application of 10% relative to control. In addition, Cu content in B. nivea roots, leaves and stems decreased by 60, 28 and 22%, respectively, for 10% RSB application. It was noted that chlorophyll content and gas exchange parameters in leaves were significantly higher at 10% RSB application than in control. Furthermore, 10% RSB resulted in a greater reduction in oxidative stress from the Cu in soil. Thus, soil amendment with RSB demonstrated positive results for Cu stabilization in aged Cu-contaminated soil, thereby reducing its accumulation and translocation in B. nivea and mitigating livestock feed security risks., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)