Contamination of vegetables with heavy metals and microplastics is a major environmental and human health concern. This study investigated the role of taurine (TAE) in alleviating arsenic (As) and polyvinyl chloride microplastic (MP) toxicity in broccoli plants. The experiment followed a completely randomized design with four replicates per treatment. Plants were grown in soil spiked with MP (200 mg kg-1), As (42.8 mg kg-1), and their combination (As + MP) with or without taurine (TAE; 100 mg L-1) foliar supplementation. Results demonstrated that MP, As, and As + MP toxicity markedly decreased growth, chlorophyll content, photosynthesis, and nutrient uptake in broccoli plants. Exposure to individual or combined MP and As increased oxidative damage, indicated by elevated methylglyoxal (MG), superoxide radical (O2 & sdot;-), hydrogen peroxide (H2O2), hydroxyl radical (& sdot;OH), and malondialdehyde (MDA) levels alongside intensified lipoxygenase (LOX) activity and leaf relative membrane permeability (RMP). Histochemical analyses revealed higher lipid peroxidation, membrane damage as well as increased H2O2 and O2 center dot- levels in the leaves of stressed plants. Micropalstic and As toxicity deteriorated anatomical structures, with diminished leaf and root epidermal thickness, cortex thickness, and vascular bundle area. However, TAE improved the antioxidant enzyme activities, endogenous ascorbate-glutathione pools, hydrogen sulfide and nitric oxide levels that reduced H2O2, O2 & sdot;-, & sdot;OH, RMP, MDA, and activity of LOX. Taurine elevated osmolyte accumulation that protected membrane integrity, resulting in increased leaf relative water content and plant biomass. Plants supplemented with TAE demonstrated improved anatomical structures, resulting in diminished As uptake and its associated phytotoxicity. These findings highlight that TAE improved redox balance, osmoregulation, ion homeostasis, and anatomical structures, augmenting tolerance to As and MP toxicity in broccoli.

The present study uncovers the impacts of pesticide-thiamethoxam (TMX- 750 mg L- 1 ) and salicylic acid (SA- 0.01, 0.1 and 1 mM) in Brassica juncea L. TMX poisoning exacerbates the nuclear and membrane damage, whereas an increment in the oxidative stress markers like hydrogen peroxide (H2O2), superoxide anions (O2- ) and malondialdehyde (MDA) contents has been observed. The significance of phytohormone SA in mitigating TMX toxicity by enhancing the growth, and antioxidant capacities of B. juncea seedlings is not well documented. Salicylic acid priming to these TMX-exposed seedlings maximizes the germination potential by 34%, and root, shoot length by 86.9% and 41.5%, whereas, minimizing the levels of oxidative stress indicators such as H2O2 by 34.8%, O 2- by 26.9% and amounts of MDA by 45.6% and EL (electrolyte leakage) contents by 22.7% under 1 mM of SA. Also, an increment in the activity of enzymatic antioxidants like superoxide dismutase (SOD), ascorbate peroxidase (APOX), glutathione peroxidase (GPOX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), peroxidase (POD), and catalase (CAT) by 122.1%, 186%, 39%, 82.61%, 40.02%, 75.6% and 59.5% was observed when TMX exposed seeds were supplemented with the highest SA (1 mM) concentration. Whereas, an upregulation in the gene expressions of enzymatic antioxidants was assessed as well as a swift decrease in the RBOH1 (respiratory burst oxidase1) gene expression was observed under the subsequent SA supplementation. Thus, the results effectively address the ameliorative potentials of exogenously applied SA in order to maximize the growth and development, by mediating osmotic adjustments, and antioxidant potentials in B. juncea L.

Exploring the saline-adapted species and the mechanisms by which they have evolved in saline conditions would be a feasible way to utilize saline soils. Based on this approach, this study aimed to evaluate the seed germination and seedling responses of the five abundant Asteraceae species to salinity stress and determine the antioxidant and non-antioxidant defense strategies by which these species demonstrated variations in salinity tolerance. Milk thistle (Silybum marianum), blessed thistle (Cnicus benedictus), pot marigold (Calendula officinalis), safflower (Carthamus tinctorius), and cardoon (Cynara cardunculus) were subjected to 0 (control), 50, 100, 150, 200 and 250 Mm NaCl concentrations. Calendula officinalis (CO) showed the highest, Silybum marianum (SM) and Cnicus benedictus (CB) moderate, and Carthamus tinctorius (CT) followed by Cynara cardunculus (CC) the least inhibition of seed germination and seedling growth at all given salinity levels. Each species utilized different antioxidant mechanisms in response to salinity. Peroxidase (POX) was the major antioxidative enzyme in resistance species, CT and CC, while catalase and superoxide dismutase were more pronounced in moderate, SM and CB, and susceptible, CO, species, respectively. Besides, all species accumulate a considerable amount of proline in response to salinity, which was more evident in the 150 and 200 Mm NaCl concentrations. From the results, it can be concluded that CT and CC had superior saline-tolerance capacity compared to other species due to their longer seedling roots, higher POX activity, and proline accumulation associated with reduced cellular damage.

Fibrous plants with higher biomass, particularly industrial hemp, have ability to withstand and accumulate significant quantities of heavy metals from contaminated environments. The present study aimed to evaluate the dynamics of different levels (ratios) of macronutrients nitrogen, phosphorus and potassium (NPK) viz., NPK1--NPK (1:1:1); NPK2--NPK (2:1:1); NPK3--NPK (3:1:2); NPK4--NPK (4:1:2) on hemp growth and Cu contents under various levels of Cu stress (100, 400 and 800 mg kg- 1 on dry soil basis using CuSO4 & sdot;5H2O). Results revealed that by increasing the Cu stress, growth and biomass decreased linearly and lipid per oxidation and enzymatic antioxidants increased. Balanced application of NPK improved the biomass and decreased the membrane damage by the modulation of malonaldehyde contents. Maximum concentration of Cu in roots (377.47 +/- 4.90 mg kg-1), shoots (137.45 +/- 5.60 mg kg-1) and (150.07 +/- 3.57 mg kg-1) was recorded at Cu3NPK2 treatment as compared to control. Maximum translocation factor (TF) and bioaccumulation coefficients (BAC) in the shoots and leaves of hemp plant were noticed where Cu stress was applied at the rate of 100 mg kg- 1. However, BAC and TF were below 1. The NPK2 treatment enhanced biomass and increase Cu content both in leaves and stems, rather than the roots. Our study suggests that balanced application of NPK is a practicable approach to alleviate Cu stress and improve biomass production of industrial hemp plant. These findings indicate that optimum nutrient supply, under Cu stress, can maximize the growth potential and overall health of industrial hemp, making it a viable option for phytoremediation and sustainable agriculture on contaminated soils.

Abiotic stress caused by soil salinization remains a major global challenge that threatens and severely impacts crop growth, causing yield reduction worldwide. In this study, we aim to investigate the damage of salt stress on the leaf physiology of two varieties of rice (Huanghuazhan, HHZ, and Xiangliangyou900, XLY900) and the regulatory mechanism of Hemin to maintain seedling growth under the imposed stress. Rice leaves were sprayed with 5.0 mmolL-1 Hemin or 25.0 mmolL-1 ZnPP (Zinc protoporphyrin IX) at the three leaf and one heart stage, followed by an imposed salt stress treatment regime (50.0 mmolL-1 sodium chloride (NaCl)). The findings revealed that NaCl stress increased antioxidant enzymes activities and decreased the content of nonenzymatic antioxidants such as ascorbate (AsA) and glutathione (GSH). Furthermore, the content of osmoregulatory substances like soluble proteins and proline was raised. Moreover, salt stress increased reactive oxygen species (ROS) content in the leaves of the two varieties. However, spraying with Hemin increased the activities of antioxidants such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and accelerated AsA-GSH cycling to remove excess ROS. In summary, Hemin reduced the effect of salt stress on the physiological characteristics of rice leaves due to improved antioxidant defense mechanisms that impeded lipid peroxidation. Thus, Hemin was demonstrated to lessen the damage caused by salt stress.

Pea (Pisum sativum L.), a globally cultivated leguminous crop valued for its nutritional and economic significance, faces a critical challenge of soil salinity, which significantly hampers crop growth and production worldwide. A pot experiment was carried out in the Botanical Garden, The Islamia University of Bahawalpur to alleviate the negative impacts of sodium chloride (NaCl) on pea through foliar application of ascorbic acid (AsA). Two pea varieties Meteor (V1) and Sarsabz (V2) were tested against salinity, i.e. 0 mM NaCl (Control) and 100 mM NaCl. Three levels of ascorbic acid 0 (Control), 5 and 10 mM were applied through foliar spray. The experimental design was completely randomized (CRD) with three replicates. Salt stress resulted in the suppression of growth, photosynthetic activity, and yield attributes in pea plants. However, the application of AsA treatments effectively alleviated these inhibitory effects. Under stress conditions, the application of AsA treatment led to a substantial increase in chlorophyll a (41.1%), chl. b (56.1%), total chl. contents (44.6%) and carotenoids (58.4%). Under salt stress, there was an increase in Na+ accumulation, lipid peroxidation, and the generation of reactive oxygen species (ROS). However, the application of AsA increased the contents of proline (26.9%), endogenous AsA (23.1%), total soluble sugars (17.1%), total phenolics (29.7%), and enzymatic antioxidants i.e. SOD (22.3%), POD (34.1%) and CAT (39%) in both varieties under stress. Salinity reduced the yield attributes while foliarly applied AsA increased the pod length (38.7%), number of pods per plant (40%) and 100 seed weight (45.2%). To sum up, the application of AsA alleviated salt-induced damage in pea plants by enhancing photosynthetic pigments, both enzymatic and non-enzymatic activities, maintaining ion homeostasis, and reducing excessive ROS accumulation through the limitation of lipid peroxidation. Overall, V2 (Sarsabz) performed better as compared to the V1 (Meteor).