Benzylaminopurine and Abscisic Acid Mitigates Cadmium and Copper Toxicity by Boosting Plant Growth, Antioxidant Capacity, Reducing Metal Accumulation and Translocation in Bamboo [Pleioblastus pygmaeus (Miq.)] Plants

6-Benzylaminopurine mediated augmentation of cadmium phytostabilization potential in Strobilanthes alternata

This study unveiled the cadmium phytoremediation potential and its augmentation using 6-Benzylaminopurine in Strobilanthes alternata. Cadmium stress was provided by applying 250 mg/kg cadmium chloride in soil and 25 ppm of 6-BAP (25 ml) was administered to the plants as foliar spray. The results revealed high bioconcentration factor (BCF) (18.82 ± 0.54) and low translocation factor (TF) values (0.055 ± 0.002) for the plant based on which we strongly recommend S. alternata as a promising candidate for Cd phytoremediation. The phytostabilization potential of the plant was further enhanced by applying 6-BAP, which augmented its BCF to 22.09 ± 0.64 and reduced the TF to 0.038 ± 0.001. Cd toxicity caused a reduction of plant growth parameters, root volume, adaxial-abaxial stomatal indices, relative water content, tolerance index, moisture content, membrane stability index, and xylem vessel diameter in S. alternata. However, Cd + 6-BAP treated plants exhibited an increase of the same compared to Cd-treated plants. FTIR analysis of Cd + 6-BAP treated plants revealed increased deposition of hemicellulose, causing enhanced retention of Cd in the root xylem walls, which is largely responsible for increased phytostabilization of Cd. Therefore, 6-BAP application in S. alternata can be exploited to restore Cd-contaminated areas effectively.

Mitigating chromium toxicity in rice (Oryza sativa L.) via ABA and 6-BAP: Unveiling synergistic benefits on morphophysiological traits and ASA-GSH cycle

In recent years, the use of plant hormones, such as abscisic acid (ABA) and 6-benzylaminopurine (6-BAP), has gained significant attention for their role in mitigating abiotic stresses across various plant species. These hormones have been shown to play a vital role in enhancing the ascorbate-glutathione cycle and eliciting a wide range of plant growth and biomass, photosynthetic efficiency, oxidative stress and response of antioxidants and other physiological responses. While previous research has been conducted on the individual impact of ABA and 6-BAP in metal stress resistance among various crop species, their combined effects in the context of heavy metal-stressed conditions remain underexplored. The current investigation is to assess the beneficial effects of single and combined ABA (5 and 10 μM L-1) and 6-BAP (5 and 10 μM L-1) applications in rice (Oryza sativa L.) cultivated in chromium (Cr)-contaminated soil (100 μM). Our results showed that the Cr toxicity in the soil showed a significant declined in the growth, gas exchange attributes, sugars, AsA-GSH cycle, cellular fractionation, proline metabolism in O. sativa. However, Cr toxicity significantly increased oxidative stress biomarkers, organic acids, enzymatic and non-enzymatic antioxidants including their gene expression in O. sativa seedlings. Although, the application of ABA and 6-BAP showed a significant increase in the plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds and their gene expression and also decreased the oxidative stress, And Cr uptake. In addition, individual or combined application of ABA and 6-BAP enhanced the cellular fractionation and decreases the proline metabolism and AsA-GSH cycle in rice plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Foliar application of iron-lysine to boost growth attributes, photosynthetic pigments and biochemical defense system in canola (Brassica napus L.) under cadmium stress

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.

Exogenous acetone O-(2-naphthylsulfonyl)oxime improves the adverse effects of excess copper by copper detoxification systems in maize

The current study is to elucidate the responses of maize seedlings to excess copper and acetone O-(2-naphthylsulfonyl)oxime (NS) pretreatment. The study was divided into the following experimental groups: 18 h distilled water (DW) control (C), 6 h 0.3 mM NS + then 12 h DW (NS), 6 h DW + then 12 h 1 mM CuSO4.5H2O (CuS), 0.3 mM NS for 6 h + then 1 mM CuSO4.5H2O (NS + CuS) for 12 h. When the NS + CuS group is compared with the CuS group; It accumulated 10% more copper, while the ABA, H2O2, MDA, and carotenoid contents decreased significantly, the total chlorophyll, proline, gallic acid, ascorbic acid, catechol, trans-P-qumaric acid, and cinnamic acid contents increased. While SOD activity, which is one of the antioxidant system enzymes, decreased with NS application, GPX, CAT, and APX activities increased despite copper stress. When all the findings are evaluated as a whole, exogenous NS, despite excessive copper, ameliorated the adverse effects of copper stress by increasing the effectiveness of the enzymatic and non-enzymatic components of the antioxidant system and the contents of phenolic substances. In addition, increasing the copper content by 10% reveals its importance in terms of NS phytoremediation.Abbreviation: Style-sheet: When full form and abbreviated form both are used as keywords, retain both as provided by the author.

Involvement of abscisic acid in silicon-mediated enhancement of copper stress tolerance in Artemisia annua

Heavy metal (HM) toxicity is a well-known hazard which causes deleterious impact on the growth and development of plants. The impact of abscisic acid (ABA) in presence of silicon (Si) on plant development and quality traits has largely gone unexplored. The effects of ABA and Si on the growth, yield, and quality characteristics of Artemisia annua L. plants growing under copper (Cu) stress (20 and 40 mg kg^-1) were investigated in a pot experiment. During this investigation, Cu stress caused severe damage to the plants but exogenous administration of Si and ABA ameliorated the harmful effects of Cu toxicity, and the plants displayed higher biomass and improved physio-biochemical attributes. Copper accumulated in the roots and shoots and its toxicity caused oxidative stress as demonstrated by the increased 2-thiobarbituric acid reactive substance (TBARS) content. It also resulted in the increased activity of antioxidant enzymes, however, the exogenous Si and ABA supplementation decreased the buildup of reactive oxygen species (ROS) and lipid peroxidation, alleviating the oxidative damage produced by HM stress. Copper toxicity had a considerable negative impact on glandular trichome density, ultrastructure as well as artemisinin production. However, combined Si and ABA enhanced the size and density of glandular trichomes, resulting in higher artemisinin production. Taken together, our results demonstrated that exogenous ABA and Si supplementation protect A. annua plants against Cu toxicity by improving photosynthetic characteristics, enhancing antioxidant enzyme activity, protecting leaf structure and integrity, avoiding excess Cu deposition in shoot and root tissues, and helping in enhanced artemisinin biosynthesis. Our results indicate that the combined application of Si and ABA improved the overall growth of plants and may thus be used as an effective approach for the improvement of growth and yield of A. annua in Cu-contaminated soils.