Physio-biochemical Parameters Research Articles

Copper oxide nanoparticles mitigate cadmium toxicity in rice seedlings through multiple physiological mechanisms.

Heavy metal pollution poses a serious threat to crops growth and yield. Recently, nanoparticles (NPs) have emerged as a promising strategy to mitigate the negative effect of heavy metal on crop growth. This study investigated the beneficial effects of copper oxide nanoparticles (CuO NPs) on the morphological and physiological-biochemical traits of rice seedlings (Oryza sativa L.) under cadmium (Cd) stress. The results demonstrated that the application of CuO NPs increased the contents of nutrition elements in shoots and roots as well as photosynthetic pigments, consequently improving the growth of rice seedlings under Cd stress, especially at low level of Cd stress. Meanwhile, CuO NPs obviously decreased the Cd accumulation in the rice seedlings and immobilized Cd in less toxic chemical forms and subcellular compartments. Moreover, CuO NPs modulated the antioxidant system, ameliorating oxidative damage and membrane injury caused by Cd. Multivariate analysis established correlations between physio-biochemical parameters and further revealed the mitigation of Cd damage to rice seedlings by CuO NPs was associated with inhibition Cd accumulation, altering Cd chemical form and subcellular distribution, increasing the contents of mineral nutrients, photosynthetic pigments and secondary metabolites and antioxidant enzyme activities, and reducing oxidative damage. Overall, the present study indicated that CuO NPs could effectively reduce the Cd toxicity to rice seedlings, demonstrating their potential application in agricultural production.

Transgenic tobacco plants overexpressing a wheat salt stress root protein (TaSSRP) exhibit enhanced tolerance to heat stress.

Heat stress is a detrimental abiotic stress that limits the development of many plant species and is linked to a variety of cellular and physiological problems. Heat stress affects membrane fluidity, which leads to negative effects on cell permeability and ion transport. Research reveals that heat stress causes severe damage to cells and leads to rapid accumulation of reactive oxygen species (ROS), which could cause programmed cell death. This current study aimed to validate the role of Triticum aestivum Salt Stress Root Protein (TaSSRP) in plants' tolerance to heat stress by modulating its expression in tobacco plants. The Relative Water Content (RWC), total chlorophyll content, and Membrane Stability Index (MSI) of the seven distinct transgenic lines (T0 - 2, T0 - 3, T0 - 6, T0 - 8, T0 - 9, T0 - 11, and T0 - 13), increased in response to heat stress. Despite the fact that the same tendency was detected in wild-type (WT) plants, changes in physio-biochemical parameters were greater in transgenic lines than in WT plants. The expression analysis revealed that the transgene TaSSRP expressed from 1.00 to 1.809 folds in different lines in the transgenic tobacco plants. The gene TaSSRP offered resistance to heat stress in Nicotiana tabacum, according to the results of the study. These findings could help to improve our knowledge and understanding of the mechanism underlying thermotolerance in wheat, and the novel identified gene TaSSRP could be used in generating wheat varieties with enhanced tolerance to heat stress.

Rab7 GTPase-Mediated stress signaling enhances salinity tolerance in AlRabring7 tobacco transgenics by modulating physio-biochemical parameters

The RING-type E3 ligases play a significant role in stress signaling, primarily through post-translational regulation. Ubiquitination is a crucial post-translational modification that regulates the turnover and activity of proteins. The overexpression of AlRabring7, RING-HC E3 Ub ligase in tobacco provides insights into the regulation of salinity and ABA signaling in transgenic tobacco. The seed germination potential of AlRabring7 transgenics was higher than WT, with NaCl and ABA treatments. The transgenics showed improved morpho-physio-biochemical parameters in response to salinity and ABA treatments. The photosynthetic pigments, soluble sugars, reducing sugars and proline increased in transgenics in response to NaCl and ABA treatments. The decreased ROS accumulation in transgenics on NaCl and ABA treatments can be co-related to improved activity of enzymatic and non-enzymatic antioxidants. The potential of transgenics to maintain ABA levels with ABA treatment, highlights the active participation of ABA feedback loop mechanism. Interestingly, the ability of AlRabring7 transgenics to upregulate Rab7 protein, suggests its role in facilitating vacuolar transport. Furthermore, the improved potassium accumulation and reduced sodium content indicate an efficient ion regulation mechanism in transgenic plants facilitating higher stomatal opening. The expression of downstream ion transporter (NbNHX1 and NbVHA1), ABA signaling (NbABI2 and NbABI5) and vesicle trafficking (NbMON1) responsive genes were upregulated with stress. The present study, reports that AlRabring7 participates in maintaining vacuolar transport, ion balance, ROS homeostasis, stomatal regulation through activation of Rab7 protein and regulation of downstream stress-responsive during stress. This emphasizes the potential of AlRabring7 gene for improved performance and resilience in challenging environments.

Impact of Foliar Application with Amino Alexin and a Mixture of Marvel Fertilizer with Growth Regulator (Floratone) in Physio-Biochemical Parameters of Bitter Orange Saplings (Citrus aurantium L.)

Impact of Foliar Application with Amino Alexin and a Mixture of Marvel Fertilizer with Growth Regulator (Floratone) in Physio-Biochemical Parameters of Bitter Orange Saplings (Citrus aurantium L.)

Astaxanthin supplementation ameliorates simulated heat stress by regulating physio-biochemical responses in Sirohi goats.

The present study was undertaken to assess the ameliorative effect of dietary supplementation of astaxanthin in Sirohi goats under simulated heat stress conditions. Eighteen healthy female Sirohi goats were divided equally into three groups (n = 6): Heat-Stressed Control (HSC), Treatment 1 (T1), and Treatment 2 (T2). During the experiment, goats in the T1 group were supplemented with astaxanthin at the rate of 25mg/animal/day, while those in the T2 group received supplementation of 50mg/animal/day. The experiment was conducted for 42 days: 14 days of acclimatization period, next 21 days animals were exposed to 42ºC for 6h from 09:00h to 15:00h and 7 days of recovery period. On a daily basis, we recorded the physiological responses of goats and collected environmental data at the experimental site. Blood samples were collected 0 and 14th days of acclimatization, on 1st, 6th, 11th, 16th and 21st day of heat exposure and on the 7th day of the recovery period. The rectal temperature and respiration rates of the treatment groups were lower than those of the HSC group during the exposure period. Heat stress in the supplemented groups was associated with reduced levels of hepatic enzymes such as AST and ALT. Serum urea, creatinine and albumin levels were significantly (P < 0.05) different between control and treatment groups. It was thus concluded that dietary inclusion of antioxidant astaxanthin can ameliorate induced thermal load as evident from changes in physio-biochemical parameters in the Sirohi goats, that was more prominent at 50mg/ animal/day than 25mg/ animal/day.

Correction to: Impact of heat stress on physio-biochemical parameters during early lactation of crossbred dairy cattle

Correction to: Impact of heat stress on physio-biochemical parameters during early lactation of crossbred dairy cattle

Ameliorative Effects of Paclobutrazol via Physio-Biochemical and Molecular Manifestation in Rice under Water Deficit Stress

We investigated the effects of an optimized dose (100 mg/kg) of paclobutrazol (PBZ) on various physio-biochemical and molecular parameters in three rice varieties (N22, IR64, and IR64 DTY1.1) under water deficit stress (WDS). Concurrently, a dose of 100 mg/kg of PBZ was applied through drenching. Samples were collected at both mild stress [75%‒80% relative water content (RWC)] and severe stress (60%‒65% RWC) conditions. Physio-biochemical parameters, including dry matter, RWC, membrane stability index (MSI), grain yield, total chlorophyll content, chlorophyll stability index, drought susceptibility index, drought tolerance efficiency, total antioxidant activity, abscisic acid (ABA) content, and gibberellic acid (GA) content, were measured. The results showed that PBZ treatment positively influenced the physio-biochemical parameters, significantly increasing dry matter (16.27%‒ 61.91%), RWC (6.48%‒16.34%), MSI (4.37%‒10.35%), and total chlorophyll content (8.97%‒29.09%) in the rice varieties under both mild and severe WDS. Moreover, PBZ treatment reduced drought susceptibility (0.83‒0.95) and enhanced drought tolerance efficiency (60.92%‒86.78%), indicating its potential as a stress-mitigating agent. This study also explored the molecular responses of the rice varieties to PBZ treatment under WDS. Global methylation analysis revealed changes in DNA methylation patterns, indicating the regulatory influence of PBZ on gene expression. The expression analysis of genes involved in the diversification of geranylgeranyl pyrophosphate towards the biosynthesis of ABA, GA, and chlorophyll showed alterations in their expression levels, suggesting the involvement of PBZ in the isoprenoid pathway. Overall, this study provides valuable insights into the potential mechanisms by which PBZ modulates physiological and molecular responses in rice plants under WDS. The findings highlight the importance of PBZ as a promising tool for enhancing drought tolerance in rice and offer valuable information for future research in crop stress management.

Effect of biopriming and nanopriming on physio-biochemical characteristics of Cicer arietinum L. under drought stress

Drought, a detrimental abiotic stress, disturbs many vital processes critical to plant growth and development resulting in subpar crop yield. Unconventional measures such as biofertilizers and nanofertilizers have been reported as reliable solutions to this, however, outcomes vary greatly depending upon the type of organism/particle and its mode of delivery. Seed priming involves treating seeds with organic/inorganic chemicals to ameliorate drought stress by boosting pre-germinative metabolism, maintaining water potential, scavenging free radicals, etc. Therefore, this study determined the effect of biopriming and nanopriming on germination percentage (GP), leaf water status (LWS), proline, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and survial percentage (SP) of BG-4958 (Drought tolerant) and ICC-1882 (Drought sensitive) chickpea varieties exposed to polyethylene glycol (PEG) induced moderate (5 %) and severe drought (10 %) at flowering with no drought acting as a control. Experimental setup had three groups, control (untreated), bioprimed with plant growth promoting endophytic bacteria (PGPEB), and nanoprimed with CuNPs synthesised from PGPEB and their chemical counterparts). Crop analysis after 15 DDS (Days to drought stress) revealed that priming significantly altered the physio-biochemical parameters. Consortium and N2X led highest increment in GP and SP for DT and DS varieties, respectively, whereas N1X showed highest increase in LWS of both. Highest accumulation of proline was observed with consortium and N1 (X & Y) in DS variety while only biological CuNPs accumulated proline for DT variety. MDA and H₂O₂ decreased significantly in treated groups thereby reducing oxidative damage with non-significant variations in DT. Lower concentrations of biological CuNPs were found to be more effective in modulating the physio-biochemical machinery of chickpea under drought than their higher concentration as well as chemical counterparts. This study deepens our understanding of the beneficial role of PGPEB and biosynthesized CuNPs in alleviating the adverse effects of drought in chickpea.

Impact of heat stress on physio-biochemical parameters during early lactation of crossbred dairy cattle

Impact of heat stress on physio-biochemical parameters during early lactation of crossbred dairy cattle

Impact of ZnO nanopriming on physiological and biochemical traits of wheat (Triticum aestivum L.) seedling

To ascertain the ideal dosage of ZnO NPs (Zinc Oxide Nanoparticles), we conducted an investigation on the priming effects of varying concentrations of ZnO NPs on germination and physio-biochemical parameters of wheat. In this study, ZnO NPs were synthesized and characterized for their physico-chemical properties followed by confirmation of the formation of ZnO NPs. Throughout this study, wheat seeds were subjected to ZnO NPs at various concentrations of 5, 50, 100, 250, and 500 ppm for a period of 4 h via continuous aeration. The primed seeds were sowed in plastic bags, allowed to grow for 21 days, following which comprehensive evaluations of physio-biochemical attributes were conducted. At 250 ppm, an impressive 100% of seeds successfully germinated compared to the control group. The examined physiological factors such as shoot length, root length, and fresh as well as dry weights of leaf and root tissues all exhibited notable increases with the ascending concentrations of ZnO NP up to 250 ppm. However, beyond this threshold, at 500 ppm, these parameters experienced a decline. Inductively coupled plasma atomic absorption spectrophotometer (ICP-AAS) measurements validated the progressive increase in Zinc content in the nanoprimed seedlings, further affirming the dose-dependent trend. Zinc oxide nanoparticles notably improved key biochemical features, including elevated levels of total chlorophyll, malondialdehyde (MDA), total protein, and the accumulation of osmolytes such as proline and glycine-betaine. Additionally, the presence of ZnO NPs led to increased activity of antioxidant enzymes like superoxide dismutase (SOD) and catalase in a dose-dependent mananer. Collectively, the amassed data underscores the efficacy of the 250 ppm ZnO NPs treatment, which emerged as superior in comparison to both the control group and other administered treatments. These findings underscore the potential of ZnO NPs at a concentration of 250 ppm as a valuable seed nanopriming agent, effectively enhanced germination and robust early-stage growth in young plants.

Effect of seasonal and regional variations on the physio-biochemical parameters of Artemisia campestris (L.) in arid and semi-arid regions of Algeria

ABSTRACT Seasonal and regional variations in biochemical and physiological parameters of Artemisia campestris (L.) were investigated. The quantification of proline by the formation of a coloured complex was done by coupling proline with ninhydrin. The determination of soluble sugars and the extraction of chlorophyll from the leaves were carried out. The seasonal average leaf proline concentration of plants from the arid region was higher than that from the semi-arid region. The more the seasonal temperature increases, the greater the concentration of proline, as with the concentrations of soluble sugars in the two study regions. The distribution and accumulation of certain minerals (e.g. Sodium and Potassium) in the plant can be modified to increase resistance to heat stress.

Unique properties of titanium dioxide quantum dots assisted regulation of growth and biochemical parameters of Hibiscus sabdariffa plants

Owing to the uniqueness of quantum dots (QDs) as a potential nanomaterial for agricultural application, hence in the present study, titanium dioxide quantum dots (TiO2 QDs) were successfully synthesized via sol-gel technique and the physico-chemical properties of the prepared TiO2 QDs were analyzed. Based on the results, the TiO2 QDs showed the presence of anatase phase of TiO2. TEM examination revealed spherical QDs morphology with an average size of 7.69 ± 1.22 nm. The large zeta potential value (-20.9 ± 2.3 mV) indicate greater stability of the prepared TiO2 QDs in aqueous solutions. Moreover, in this work, the application of TiO2 QDs on Hibiscus sabdariffa plants was conducted, where H. sabdariffa plants were foliar sprayed twice a week in the early morning with different concentrations of TiO2 QDs (0, 2, 5, 10, 15 and 30 ppm) to evaluate their influence on these plants in terms of morphological indexes and biochemical parameters. The results exhibited an increasing impact of the different used concentrations of TiO2 QDs on morphological indexes, such as fresh weight, dry weight, shoot length, root length, and leaf number, and physio-biochemical parameters like chlorophyll a, chlorophyll b, carotenoid contents, total pigments and total phenolic contents. Remarkably, the most prominent result was recorded at 15 ppm TiO2 QDs where plant height, total protein and enzymatic antioxidants like catalase and peroxidase were noted to increase by 47.6, 20.5, 29.5 and 38.3%, respectively compared to control. Therefore, foliar spraying with TiO2 QDs positively serves as an effective strategy for inducing optimistic effects in H. sabdariffa plants.

Bio-stimulants from medicinally and nutritionally significant plant extracts mitigate drought adversities in Zea mays through enhanced physiological, biochemical, and antioxidant activities

Drought stress poses a substantial threat to global plant productivity amid increasing population and rising agricultural demand. To overcome this problem, the utilization of organic plant growth ingredients aligns with the emphasis on eco-friendly farming practices. Therefore, the present study aimed to assess the influence of 30 botanical extracts on seed germination, seedling vigor, and subsequent maize plant growth under normal and water deficit conditions. Specifically, eight extracts showed significant enhancement in agronomical parameters (ranging from ∼2 % to ∼ 183 %) and photosynthetic pigments (ranging from ∼21 % to ∼ 195 %) of seedlings under drought conditions. Extended tests on maize in a greenhouse setting confirmed that the application of six extracts viz Moringa oleifera leaf (MLE), bark (MBE), Terminalia arjuna leaf (ALE), bark (ABE), Aegel marmelos leaf (BLE), and Phyllanthus niruri leaf (AmLE) improved plant growth and drought tolerance, as evident in improved physio-biochemical parameters. GC-MS analysis of the selected extracts unveiled a total of 51 bioactive compounds, including sugars, sugar alcohols, organic acids, and amino acids, and might be playing pivotal roles in plant acclimatization to drought stress. In conclusion, MLE, MBE, BLE, and ABE extracts exhibit significant potential for enhancing seedling establishment and growth in maize under both normal and water deficit conditions.

Salicylic acid and chitosan mitigate high temperature stress of rice via growth improvement, physio-biochemical adjustments and enhanced antioxidant activity

Sustainably increasing rice (Oryza sativa L.) becomes more challenging due to environmental stresses. High temperature stress resulting from global warming impact of climate change is highly damaging as it can cause growth and yield reduction of rice via cellular and physio-biochemical impairments. Application of either salicylic acid or chitosan can possibly increase plant's tolerance to different abiotic stresses; however, their combined mitigation effects remained inadequately explored. Thus, the objective of the current study was to evaluate the mitigation potential of combined salicylic acid and chitosan against high temperature stress of rice. The experiment was conducted in a factorial combination of two temperature regimes (optimum temperature [control] and high temperature); two salicylic acid levels (−SA: 0 mg L−1 and +SA: 140 mg L−1); and two chitosan levels (−Ch: 0 mg L−1, +Ch: 100 mg L−1) following a completely randomized design. High temperature impaired rice growth and productivity by negatively influencing all tested parameters; however, salicylic acid and chitosan could significantly mitigate those impairments. The mitigation on growth and yield contributing parameters was recorded at best 11 %, 21 %, 12 %, 75 %, 61 %, 46 %, 27 %, and 43 % for plant height, leaf area, shoot dry matter, pollen viability, effective tiller percentage, filled grain percentage, 1000-grain weight, and grain yield respectively. Highest alleviation in physio-biochemical parameters was also found at best 35 %, 68 %, and 67 % for leaf greenness, net photosynthetic rate, and stomatal conductance respectively with 28 % and 60 % respective increase in transpiration rate and proline concentration. Superoxide dismutase, catalase, ascorbate peroxidase and peroxidase activity were also boosted as high as 1.6-folds, 1.4-folds, 1.9-folds, and 2.6-folds respectively with subsequent reduction of 32 % lipid peroxidation and 34 % hydrogen peroxide concentration. For all tested parameters, the best positive effects were observed under combined salicylic acid and chitosan treatment. Individually, salicylic acid was found more effective than chitosan; however, their combined application resulted in significantly better alleviation responses over their individual application for most studied parameters. Our findings would contribute in present understanding of high temperature stress and would also help in strategizing better-suited management practices toward sustainable rice productivity.

Drought Stress Alleviator Melatonin Reconfigures Water-Stressed Barley (Hordeum vulgare L.) Plants' Photosynthetic Efficiency, Antioxidant Capacity, and Endogenous Phytohormone Profile.

The production of crops is severely limited by water scarcity. We still do not fully understand the underlying mechanism of exogenous melatonin (MT)-mediated water stress tolerance in barley. This study is the first of its kind to show how MT can potentially mitigate changes in barley's physio-biochemical parameters caused by water deficiency. Barley was grown under three irrigation levels (100%, 70%, and 30% of field capacity) and was foliar sprayed with 70 μM MT. The results showed that exogenously applied MT protected the photosynthetic apparatus by improving photosynthetic pigment content, photochemical reactions of photosynthesis, Calvin cycle enzyme activity, gas exchange capacity, chlorophyll fluorescence system, and membrane stability index. Furthermore, the increased levels of salicylic acid, gibberellins, cytokinins, melatonin, and indole-3-acetic acid, as well as a decrease in abscisic acid, indicated that foliar-applied MT greatly improved barley water stress tolerance. Additionally, by increasing the activity of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and decreasing hydrogen peroxide content, lipid peroxidation, and electrolyte leakage, MT application lessened water stress-induced oxidative stress. According to the newly discovered data, MT application improves barley water stress tolerance by reprogramming endogenous plant hormone production and antioxidant activity, which enhances membrane stability and photosynthesis. This study unraveled MT's crucial role in water deficiency mitigation, which can thus be applied to water stress management.

Exogenous γ-aminobutyric acid improves the photosynthesis efficiency, soluble sugar contents, and mineral nutrients in pomegranate plants exposed to drought, salinity, and drought-salinity stresses

Backgroundγ-aminobutyric acid (GABA), as a regulator of many aspects of plant growth, has a pivotal role in improving plant stress resistance. However, few studies have focused on the use of GABA in increasing plants’ resistance to interactional stresses, such as drought-salinity. Therefore, the focus of this study was to examine the effect of foliar application of GABA (0, 10, 20, and 40 mM) on growth indices and physio-biochemical parameters in plants of two pomegranate cultivars, ‘Rabab’ and ‘Atabaki’ exposed to drought, salinity, and drought-salinity.ResultsUnder stress conditions, the photosynthetic capacity of two pomegranate cultivars, including transpiration rate, net photosynthetic rate, intercellular carbon dioxide concentration, stomatal conductance of water vapour, and mesophyll conductance, was significantly reduced. This resulted in a decrease in root morphological traits such as fresh and dry weight, diameter, and volume, as well as the fresh and dry weight of the aerial part of the plants. However, the application of GABA reversed the negative effects caused by stress treatments on growth parameters and maintained the photosynthetic capacity. GABA application has induced the accumulation of compatible osmolytes, including total soluble carbohydrate, starch, glucose, fructose, and sucrose, in charge of providing energy for cellular defense response against abiotic stresses. Analysis of mineral nutrients has shown that GABA application increases the absorption of potassium, potassium/sodium, magnesium, phosphorus, manganese, zinc, and iron. As concentration increased up to 40 mM, GABA prevented the uptake of toxic ions, sodium and chloride.ConclusionsThese findings highlight the potential of GABA as a biostimulant strategy to enhance plant stress tolerance.

Physio-biochemical responses of registered bread wheat (Triticum aestivum L.) genotypes to drought stress: Variations in antioxidant parameters and photosynthetic pigment amounts

In this study, physio-biochemical parameters of 7 registered bread wheat (Triticum aestivum L.) genotypes (Gerek 79, Sultan 95, Haymana 79, Grk/Cty, T98-9, Pastor, PM ME1) were investigated under drought stress conditions. Polyphenol oxidase (PPO), peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), photosynthetic pigment, total protein, hydrogen peroxide, lipid peroxidation (malonyldialdehyde-MDA) and proline levels were determined in this wheat genotypes exposed to different drought duration (3rd, 6th and 10th day). As a result of this study, among 7 different wheat genotypes, Gerek 79 and Haymana 79 genotypes were the most physiologically sensitive to drought. In comparison, Pastor and Sultan 95 genotypes were the most drought-tolerant varieties. In addition, in parallel with the prolongation of the drought period in wheat varieties in general, it was determined that the content of photosynthetic pigments decreased significantly due to oxidative damage, while proline and MDA content increased

Prospects of Bacillus amyloliquefaciens (MZ945930) Mediated Enhancement of Capsicum annuum L. Plants Under Stress of Alternaria alternata in Terms of Physiological Traits, Thiol Content, Antioxidant Defense, and Phytohormones

AbstractPlants encounter many biotic entities, such as fungi, bacteria, and nematodes, which induce biotic stress that disrupts normal metabolism and limits the growth and productivity of plants. Currently, the use of plant growth-promoting bacterial endophytes instead of synthetic fungicides is intriguingly eco-friendly. An in vitro and in vivo antagonistic approach using Bacillus amyloliquefaciens RaSh1 was used to mimic the pathogenic effect of Alternaria alternata. The results showed that B. amyloliquefaciens significantly inhibited pathogenic fungal growth in vitro. Further, Capsicum annuum L. (pepper plants) were grown and subjected to inoculation with B. amyloliquefaciens and infected with A. alternata, and then the growth attributes, photosynthetic pigments, physio-biochemical parameters, and the level of endogenous phytohormones were assessed. Under the pathogen attack, the main responses, such as plant length, total fresh and dry weights, total chlorophylls, and pigments, were reduced, accompanied by increases in H2O2. As well, infection of pepper with A. alternata caused downregulation in the plant hormonal system by significantly decreasing gibberellins, indole-3-acetic acid, abscisic acid, as well as cytokinin concentrations. Although, with B. amyloliquefaciens application, an enhancement in growth, photosynthetic pigments, proline, thiol content, phenylalanine ammonia-lyase, and peroxidase in pepper plant leaves appeared while the content of H2O2 decreased. Endogenous phytohormones were found to be upregulated in B. amyloliquefaciens-inoculated and diseased plants. The current study found that B. amyloliquefaciens RaSh1 rescued pepper plant growth by modulating antioxidant defense and regulating hormones, and could be used to control A. alternata in an environmentally friendly manner while maintaining sustainable agriculture and food security.

Alkaline and acidic soil constraints on iron accumulation by Rice cultivars in relation to several physio-biochemical parameters

Agricultural production is severely limited by an iron deficiency. Alkaline soils increase iron deficiency in rice crops, consequently leading to nutrient deficiencies in humans. Adding iron to rice enhances both its elemental composition and the nutritional value it offers humans through the food chain. The purpose of the current pot experiment was to investigate the impact of Fe treatment in alkaline (pH 7.5) and acidic (pH 5.5) soils to introduce iron-rich rice. Iron was applied to the plants in the soil in the form of an aqueous solution of FeSO4 with five different concentrations (100, 200, 300, 400, and 500 mM). The results obtained from the current study demonstrated a significant increase in Fe content in Oryza sativa with the application of iron in both alkaline and acidic pH soils. Specifically, Basmati-515, one of the rice cultivars tested, exhibited a notable 13% increase in iron total accumulation per plant and an 11% increase in root-to-shoot ratio in acidic soil. In contrast to Basmati-198, which demonstrated maximum response in alkaline soil, Basmati-515 exhibited notable increases in all parameters, including a 31% increase in dry weight, 16% increase in total chlorophyll content, an 11% increase in CAT (catalase) activity, 7% increase in APX (ascorbate peroxidase) activity, 26% increase in POD (peroxidase) activity, and a remarkable 92% increase in SOD (superoxide dismutase) in acidic soil. In alkaline soil, Basmati-198 exhibited respective decreases of 40% and 39% in MDA and H2O2 content, whereas Basmati-515 demonstrated a more significant decrease of 50% and 67% in MDA and H2O2 in acidic soil. These results emphasize the potential for targeted soil management strategies to improve iron nutrition and address iron deficiency in agricultural systems. By considering soil conditions, it is possible to enhance iron content and promote its availability in alkaline and acidic soils, ultimately contributing to improved crop nutrition and human health.

Foliar application of glycine betaine to ameliorate lead toxicity in barley plants by modulating antioxidant enzyme activity and biochemical parameters

Lead (Pb) toxicity is a major problem in agricultural soil that negatively affects plant growth and development. Glycine betaine (GB) is an effective compatible solute that resists abiotic stress and plays an important role to mitigate various stresses. The present study is the first of its kind on the application of GB to mitigate Pb toxicity on barley cultivars. To elucidate the role of GB in mitigating Pb toxicity of three concentrations (15 mM, 25 mM, and 35 mM) in two barley varieties (BH-959 and BH-946) with and without foliar application of GB (2 mM) was examined. The study found that increasing Pb concentration significantly (p < 0.05) reduced the level of primary metabolites viz. photosynthetic pigments, protein, and carbohydrates in both cultivars upto 42.4%, 38.4% and 39% respectively. However malondialdehyde content, proline content, and antioxidant enzyme activity (SOD, CAT, and POX) were found to increased significantly (p < 0.05) as compared to control treatment upto 83.4%, 83.2% and 51% respectively. In contrast, the application of GB led to significantly (p < 0.05) improved physio-biochemical parameters as well as antioxidant enzyme activity (53%) and reduced oxidative stress along with malondialdehyde content (14.42%) in both varieties. An increment in these parameters revealed that exogenous application of GB (2 mM) significantly improves Pb (up to 35 mM) toxicity in barley plants and its use may be beneficial for crops susceptible to Pb toxicity to improve growth and yield.