Metal-tolerant and siderophore producing Pseudomonas fluorescence and Trichoderma spp. improved the growth, biochemical features and yield attributes of chickpea by lowering Cd uptake

Biopriming with multifarious sulphur-oxidizing bacteria improve in vitro Vigna radiata L. (mung bean) and Brassica juncea L. (mustard) seed germination

Biopriming seeds with beneficial bacteria has potential to enhance seed germination. Therefore, in this investigation, five sulphur-oxidizing bacterial cultures, viz., Pantoea dispersa SOB2, Bacillus velezensis SN06, Bacillus cereus SN20, Bacillus tropicus SN16, and Bacillus megaterium SN11, were evaluated for different plant growth-promoting traits and their impact on Vigna radiata L. (mung bean) and Brassica juncea L. (mustard) seed germination. Among these, three bacterial cultures Pantoea dispersa SOB2, Bacillus velezensis SN06, and Bacillus megaterium SN11 evinced potential for mineral solubilization on solid medium where Pantoea dispersa SOB2 had the maximum solubilization indices-3.06, 5.14, and 2.48 for phosphate, zinc, and potassium respectively. The culture also displayed higher indole acetic acid (113.12 µg/mL), gibberellic acid (162.66 µg/mL), ammonia (5.23 µg/mL), and siderophore (69.53%) production than other bacterial cultures whereas Bacillus cereus SN20 showed maximum exopolysaccharide production (9.26 g/L). Bacterial culture Pantoea dispersa SOB2 significantly ameliorated the germination rate (3.73 no./day) and relative seed germination (208%) of Brassica juncea L., while Bacillus velezensis SN06 and Bacillus cereus SN20 followed with germination rate and relative seed germination of 2.86 no./day and 207%, respectively. Pantoea dispersa SOB2 displayed lowest mean germination time 2.91 days followed by Bacillus megaterium SN11 with 3.19 days. Biopriming with sulphur-oxidizing bacterial cultures, germination parameters of Vigna radiata L. were also markedly improved. Pantoea dispersa SOB2 demonstrated the highest germination rate (6.72 no./day), relative seed germination (115.56%), and minimum mean generation time (1.73 days). Bacillus velezensis SN06 inoculation had a beneficial effect on the seedling growth of Vigna radiata L., whereas Pantoea dispersa SOB2 greatly aided the seedling growth of Brassica juncea L. Results corroborated a prominent positive correlation between seed germination and plant growth-promoting traits. This is the first study on Pantoea dispersa as sulphur oxidizer, displaying plant growth promoting traits and seed germination potential. The potent sulphur-oxidizing bacterial cultures possessing plant growth promoting activities enhanced seed germination under in vitro conditions that could be further explored in field as biofertilizers to enhance the growth and yield of Brassica juncea L. and Vigna radiata L. crop.

The Contribution of Trichoderma viride and Metallothioneins in Enhancing the Seed Quality of Avena sativa L. in Cd-Contaminated Soil

Pollution of arable land with heavy metals is a worldwide problem. Cadmium (Cd) is a toxic metal that poses a severe threat to humans' and animals' health and lives. Plants can easily absorb Cd from the soil, and plant-based food is the main means of exposure to this hazardous element for humans and animals. Phytoremediation is a promising plant-based approach to removing heavy metals from the soil, and plant growth-promoting micro-organisms such as the fungi Trichoderma can enhance the ability of plants to accumulate metals. Inoculation of Avena sativa L. (oat) with Trichoderma viride enhances germination and seedling growth in the presence of Cd and, in this study, the growth of 6-month-old oat plants in Cd-contaminated soil was not increased by inoculation with T. viride, but a 1.7-fold increase in yield was observed. The content of Cd in oat shoots depended on the Cd content in the soil. Still, it was unaffected by the inoculation with T. viride. A. sativa metallothioneins (AsMTs) participate in plant-fungi interaction, however, their role in this study depended on MT type and Cd concentration. The inoculation of A. sativa with T. viride could be a promising approach to obtaining a high yield in Cd-contaminated soil without increasing the Cd content in the plant.

Unboxing PGPR-mediated management of abiotic stress and environmental cleanup: what lies inside?

Abiotic stresses including heavy metal toxicity, drought, salt and temperature extremes disrupt the plant growth and development and lowers crop output. Presence of environmental pollutants further causes plants suffering and restrict their ability to thrive. Overuse of chemical fertilizers to reduce the negative impact of these stresses is deteriorating the environment and induces various secondary stresses to plants. Therefore, an environmentally friendly strategy like utilizing plant growth-promoting rhizobacteria (PGPR) is a promising way to lessen the negative effects of stressors and to boost plant growth in stressful conditions. These are naturally occurring inhabitants of various environments, an essential component of the natural ecosystem and have remarkable abilities to promote plant growth. Furthermore, multifarious role of PGPR has recently been widely exploited to restore natural soil against a range of contaminants and to mitigate abiotic stress. For instance, PGPR may mitigate metal phytotoxicity by boosting metal translocation inside the plant and changing the metal bioavailability in the soil. PGPR have been also reported to mitigate other abiotic stress and to degrade environmental contaminants remarkably. Nevertheless, despite the substantial quantity of information that has been produced in the meantime, there has not been much advancement in either the knowledge of the processes behind the alleged positive benefits or in effective yield improvements by PGPR inoculation. This review focuses on addressing the progress accomplished in understanding various mechanisms behind the protective benefits of PGPR against a variety of abiotic stressors and in environmental cleanups and identifying the cause of the restricted applicability in real-world.

Unveiling the potential of A. fabrum and γ-aminobutyric acid for mitigation of nickel toxicity in fenugreek

Nickel (Ni) is a heavy metal that adversely affects the growth of different crops by inducing oxidative stress and nutrient imbalance. The role of rhizobacteria (RB) is vital to resolve this issue. They can promote root growth and facilitate the uptake of water and nutrients, resulting in better crop growth. On the other hand, γ-aminobutyric acid (GABA) can maintain the osmotic balance and scavenge the reactive oxygen species under stress conditions. However, the combined effect of GABA and RB has not been thoroughly explored to alleviate Ni toxicity, especially in fenugreek plants. Therefore, in the current pot study, four treatments, i.e., control, A. fabrum (RB), 0.40 mM GABA, and 0.40 mM GABA + RB, were applied under 0Ni and 80 mg Ni/kg soil (80Ni) stress. Results showed that RB + 0.40 mM GABA caused significant improvements in shoot length (~ 13%), shoot fresh weight (~ 47%), shoot dry weight (~ 47%), root length (~ 13%), root fresh weight (~ 60%), and root dry weight (~ 15%) over control under 80 Ni toxicity. A significant enhancement in total chlorophyll (~ 14%), photosynthetic rate (~ 17%), stomatal CO2 concentration (~ 19%), leaves and roots N (~ 10 and ~ 37%), P (~ 18 and ~ 7%) and K (~ 11 and ~ 30%) concentrations, while a decrease in Ni (~ 83 and ~ 49%) concentration also confirmed the effectiveness of RB + 0.40 mM GABA than control under 80Ni. In conclusion, fabrum + 0.40 mM GABA can potentially alleviate the Ni toxicity in fenugreek plants. The implications of these findings extend to agricultural practices, environmental remediation efforts, nutritional security, and ecological impact. Further research is recommended to elucidate the underlying mechanisms, assess long-term effects, and determine the practical feasibility of using A. fabrum + 0.40GABA to improve growth in different crops under Ni toxicity.

Bioremediation of Pb contaminated water using a novel Bacillus sp. strain MHSD_36 isolated from Solanum nigrum

The Pb bioremediation mechanism of a multi-metal resistant endophytic bacteria Bacillus sp. strain MHSD_36, isolated from Solanum nigrum, was characterised. The strain tested positive for the presence of plant growth promoters such as indoleacetic acid, 1-aminocyclopropane-1-carboxylate deaminase, siderophores, and phosphate solubilization. The experimental data illustrated that exopolysaccharides and cell hydrophobicity played a role in Pb uptake. The data further showed that the cell wall biosorbed a significant amount (71%) of the total Pb (equivalent to 4 mg/L) removed from contaminated water, compared to the cell membrane (11%). As much as 11% of the Pb was recovered from the cytoplasmic fraction, demonstrating the ability of the strain to control the influx of toxic heavy metals into the cell and minimize their negative impacts. Pb biosorption was significantly influenced by the pH and the initial concentration of the toxic ions. Furthermore, the presence of siderophores and biosurfactants, when the strain was growing under Pb stress, was detected through liquid chromatography mass spectrometry. The strain demonstrated a multi-component based Pb biosorption mechanism and thus, has a great potential for application in heavy metal bioremediation.

Purification and Characterization of Desferrioxamine B of Pseudomonas fluorescens and Its Application to Improve Oil Content, Nutrient Uptake, and Plant Growth in Peanuts

Microorganisms produce siderophores, which are low-molecular-weight iron chelators when iron availability is limited. The present analyzed the role of LNPF1 as multifarious PGPR for improving growth parameters and nutrient content in peanut and soil nutrients. Such multifarious PGPR strains can be used as effective bioinoculants for peanut farming. In this work, rhizosphere bacteria from Zea mays and Arachis hypogaea plants in the Salem area of Tamil Nadu, India, were isolated and tested for biochemical attributes and characteristics that stimulate plant growth, such as the production of hydrogen cyanide, ammonia (6 µg/mL), indole acetic acid (76.35 µg/mL), and solubilizing phosphate (520 µg/mL). The 16S rRNA gene sequences identified the isolate LNPF1 as Pseudomonas fluorescens with a similarity percentage of 99% with Pseudomonas sp. Isolate LNPF1 was evaluated for the production of siderophore. Siderophore-rich supernatant using a Sep Pack C18 column and Amberlite-400 Resin Column (λmax 264) produced 298 mg/L and 50 mg/L of siderophore, respectively. The characterization of purified siderophore by TLC, HPLC, FTIR, and 2D-NMR analysis identified the compound as desferrioxamine, a hydroxamate siderophore. A pot culture experiment determined the potential of LNPF1 to improve iron and oil content and photosynthetic pigments in Arachis hypogaea L. and improve soil nutrient content. Inoculation of A. hypogea seeds with LNPF1 improved plant growth parameters such as leaf length (60%), shoot length (22%), root length (54.68%), fresh weight (47.28%), dry weight (37%), and number of nuts (66.66) compared to the control (untreated seeds). This inoculation also improved leaf iron content (43.42), short iron content (38.38%), seed iron (46.72%), seed oil (31.68%), carotenoid (64.40%), and total chlorophyll content (98.%) compared to control (untreated seeds). Bacterized seeds showed a substantial increase in nodulation (61.65%) and weight of individual nodules (95.97) vis-à-vis control. The results of the present study indicated that P. fluorescens might be utilized as a potential bioinoculant to improve growth, iron content, oil content, number of nuts and nodules of Arachishypogaea L., and enrich soil nutrients.

Trichoderma Inoculation Alleviates Cd and Pb-Induced Toxicity and Improves Growth and Physiology of Vigna radiata (L.)

Heavy metals (HMs) pose a serious threat to agricultural productivity. Therefore, there is a need to find sustainable approaches to combat HM stressors in agriculture. In this study, we isolated Trichoderma sp. TF-13 from metal-polluted rhizospheric soil, which has the ability to resist 1600 and 1200 μg mL-1 cadmium (Cd) and lead (Pb), respectively. Owing to its remarkable metal tolerance, this fungal strain was applied for bioremediation of HMs in Vigna radiata (L.). Strain TF-13 produced siderophore, salicylic acid (SA; 43.4 μg mL-1) and 2,3-DHBA (21.0 μg mL-1), indole-3-acetic acid, ammonia, and ACC deaminase under HM stressed conditions. Increasing concentrations of tested HM ions caused severe reduction in overall growth of plants; however, Trichoderma sp. TF-13 inoculation significantly (p ≤ 0.05) increased the growth and physiological traits of HM-treated V. radiata. Interestingly, Trichoderma sp. TF-13 improved germination rate (10%), root length (26%), root biomass (32%), and vigor index (12%) of V. radiata grown under 25 μg Cd kg-1 soil. Additionally, Trichoderma inoculation showed a significant (p ≤ 0.05) increase in total chlorophyll, chl a, chl b, carotenoid content, root nitrogen (N), and root phosphorus (P) of 100 μg Cd kg-1 soil-treated plants over uninoculated treatment. Furthermore, enzymatic and nonenzymatic antioxidant activities of Trichoderma inoculated in metal-treated plants were improved. For instance, strain TF-13 increased proline (37%), lipid peroxidation (56%), catalase (35%), peroxidase (42%), superoxide dismutase (27%), and glutathione reductase (39%) activities in 100 μg Pb kg-1 soil-treated plants. The uptake of Pb and Cd in root/shoot tissues was decreased by 34/39 and 47/38% in fungal-inoculated and 25 μg kg-1 soil-treated plants. Thus, this study demonstrates that stabilizing metal mobility in the rhizosphere through Trichoderma inoculation significantly reduced the detrimental effects of Cd and Pb toxicity in V. radiata and also enhanced development under HM stress conditions.

Sustainable remediation of chromium-contaminated soils: boosting radish growth with deashed biochar and strigolactone

Chromium (Cr) stress significantly hinders crop production by disrupting nutrient uptake, impairing plant growth, and contaminating soil, posing a substantial threat to agricultural sustainability. The use of deashed biochar (DAB) and strigolactone can be an effective solution to mitigate this issue. Deashed biochar enhances crop production by improving soil structure, water retention, and nutrient availability while mitigating the bioavailability of toxic substances. Strigolactone boosts plant growth by stimulating root growth, branching, shoot formation, and overall plant physiology. Nevertheless, the scientific rationale behind their collective use as an amendment to counter Cr stress remains to be substantiated. Therefore, in this study, a blend of DAB and strigolactone was employed as additives in radish cultivation, both in the absence of Cr stress and under the influence of 200Cr stress. Four treatments, i.e., 0, 20µM Strigolactone, DAB, and 20µM Strigolactone + DAB, were applied in four replications following a completely randomized design. Results demonstrate that 20µM Strigolactone + DAB produced significant improvement in radish shoot length (27.29%), root length (45.60%), plant fresh weight (33.25%), and plant dry weight (78.91%), compared to the control under Cr stress. Significant enrichment in radish chlorophyll a (20.41%), chlorophyll b (58.53%), and total chlorophyll (31.54%) over the control under Cr stress, prove the efficacy of 20µM Strigolactone + DAB treatment. In conclusion, 20µM Strigolactone + DAB is the recommended amendment for mitigating Cr stress in radish. Farmers should consider using Strigolactone + DAB amendments to combat Cr stress and enhance radish growth, contributing to a more resilient agricultural ecosystem.

Enhanced use of chemical fertilizers and mitigation of heavy metal toxicity using biochar and the soil fungus Bipolaris maydis AF7 in rice: Genomic and metabolomic perspectives

Chemical fertilizers are the primary source of crop nutrition; however, their increasing rate of application has created environmental hazards, such as heavy metal toxicity and eutrophication. The synchronized use of chemical fertilizers and eco-friendly biological tools, such as microorganisms and biochar, may provide an efficient foundation to promote sustainable agriculture. Therefore, the current study aimed to optimize the nutrient uptake using an inorganic fertilizer, sulfate of potash (SOP) from the plant growth-promoting fungus Bipolaris maydis AF7, and biochar under heavy metal toxicity conditions in rice. Bioassay analysis showed that AF7 has high resistance to heavy metals and a tendency to produce gibberellin, colonize the fertilizer, and increase the intake of free amino acids. In the plant experiment, the co-application of AF7 +Biochar+MNF+SOP significantly lowered the heavy metal toxicity, enhanced the nutrient uptake in the rice shoots, and improved the morphological attributes (total biomass). Moreover, the co-application augmented the glucose and sucrose levels, whereas it significantly lowered the endogenous phytohormone levels (salicylic acid and jasmonic acid) in the rice shoots. The increase in nutrient content aligns with the higher expression of the OsLSi6, PHT1, and OsHKT1 genes. The plant growth traits and heavy metal tolerance of AF7 were validated by whole-genome sequencing that showed the presence of the heavy metal tolerance and detoxification protein, siderophore iron transporter, Gibberellin cluster GA4 desaturase, and DES_1 genes, as well as others that regulate glucose, antioxidants, and amino acids. Because the AF7 +biochar+inorganic fertilizer works synergistically, nutrient availability to the crops could be improved, and heavy metal toxicity and environmental hazards could be minimized.

Alshamari AKA, Alshammari EM, Ahmed A. O, Sherwani S, Ali Khan MW. Bioremediation potential of Pseudomonas fluorescens strain isolated from the Ha'il region of Saudi Arabia

Increased amounts of toxicants may cause sever health issues in humans as well as in aquatic life. Scientists are developing new technologies to combat these problems. Biological methods of detoxification are always beneficial for the environment. Pseudomonas fluorescens is known for its detoxification capacity. In this study Pseudomonas fluorescens stains were isolated from different locations of the Ha'il region, Saudia Arabia. The microbial strain AM-1 displayed resistance to heavy metals (Cr6+, Ni2+, Cd2+, Pb2+) and pesticides (BHC, 2,4-D, Mancozeb) at pollutant levels typical of highly contaminated areas. Additionally, AM-1 exhibited substantial detoxification potential, reducing toxicity by 40.67% for heavy metals and 47.4% for pesticides at 3x concentrations. These findings suggest that the AM-1 strain supports environmental remediation and pollution mitigation. Atomic absorption spectrometry (AAS) results exhibited bioremediation efficiency for metals Cr6+, Ni2+, and Pb2+ using immobilized cells of P. fluorescens AM-1 isolate, estimated to be 60.57%, 68.4%, and 53.93% respectively. These findings show that AM-1 strain has a potential role in bioremediation of water pollutants and may have future implications in wastewater treatment.

Zinc Foliar Application Mitigates Cadmium-Induced Growth Inhibition and Enhances Wheat Growth, Chlorophyll Contents, and Yield

Cadmium (Cd) is a toxic heavy metal that significantly threatens plants and the environment. Its toxicity in plants can result in various adverse effects, including reduced growth, altered metabolism, and cell damage. Cadmium can also interfere with nutrient uptake, particularly zinc (Zn), leading to Zn deficiency and further exacerbating Cd toxicity. On the other hand, foliar application of zinc might be a useful strategy to mitigate cadmium (Cd) toxicity in plants. Hence, a pot experiment was conducted with three replications. The wheat plants were treated with various concentrations of Zn as a foliar spray (control, 0.1, 0.2, 0.4, and 0.5%) in Cd-spiked soil in pots. The results showed that foliar use of Zn at 0.4 or 0.5% resulted in higher plant height, grain yield, and dry matter yield than the control group. Using Zn as foliar spray enriched shoot and grain Zn content while reducing Cd content in the shoot and grain. The leaf's electrolyte leakage (EL) decreased by 15.4, 29.8, 40.7, and 45.9% in the Zn 0.1%, Zn 0.2%, Zn 0.4%, and Zn 0.5% treatments, respectively, compared to the control treatment. Regarding superoxide dismutase (SOD) activity, Zn 0.5% treatment showed a decrease of 42.9% over control. Specifically, the Zn 0.1% showed a 27.2%, Zn 0.2% showed a 56.8%, Zn 0.4% showed a 91.1%, and Zn 0.5% showed a 133.7% increase in total chlorophyll content than control. Based on the results, it is recommended that 0.4% Zn solution may be used for foliar application for enhancing crop productivity and Zn concentration in plants under high Cd stress. Additionally, continued research on the mechanisms of cadmium uptake, transport, and detoxification in plants may lead to the identification of new targets for intervention.

Phyto-microbiome to mitigate abiotic stress in crop plants

Plant-associated microbes include taxonomically diverse communities of bacteria, archaebacteria, fungi, and viruses, which establish integral ecological relationships with the host plant and constitute the phyto-microbiome. The phyto-microbiome not only contributes in normal growth and development of plants but also plays a vital role in the maintenance of plant homeostasis during abiotic stress conditions. Owing to its immense metabolic potential, the phyto-microbiome provides the host plant with the capability to mitigate the abiotic stress through various mechanisms like production of antioxidants, plant growth hormones, bioactive compounds, detoxification of harmful chemicals and toxins, sequestration of reactive oxygen species and other free radicals. A deeper understanding of the structure and functions of the phyto-microbiome and the complex mechanisms of phyto-microbiome mediated abiotic stress mitigation would enable its utilization for abiotic stress alleviation of crop plants and development of stress-resistant crops. This review aims at exploring the potential of phyto-microbiome to alleviate drought, heat, salinity and heavy metal stress in crop plants and finding sustainable solutions to enhance the agricultural productivity. The mechanistic insights into the role of phytomicrobiome in imparting abiotic stress tolerance to plants have been summarized, that would be helpful in the development of novel bioinoculants. The high-throughput modern approaches involving candidate gene identification and target gene modification such as genomics, metagenomics, transcriptomics, metabolomics, and phyto-microbiome based genetic engineering have been discussed in wake of the ever-increasing demand of climate resilient crop plants.

Rhizobacterial Isolates from Prosopis limensis Promote the Growth of Raphanus sativus L. Under Salt Stress

Microbial biotechnology employes techniques that rely based on the natural interactions that occur in ecosystems. Bacteria, including rhizobacteria, play an important role in plant growth, providing agricultural crops with an alternative that can mitigate the negative effects of abiotic stress, such as those caused by saline environments. In this study, bacterial isolates were obtained from soil and roots of Prosopis limensis Bentham from the department of Lambayeque, Peru. This region has high salinity levels, therefore, the collected samples were used to isolate plant growth-promoting rhizobacteria (PGPR), which were identified through morphological, and physical-biochemical characteristics. These salt tolerant bacteria were screened phosphate solubilization, indole acetic acid, deaminase activity and molecular characterization by 16S rDNA sequencing. Eighteen samples from saline soils of the Prosopis limensis plants in the northern coastal desert of San Jose district, Lambayeque, Peru. The bacterial isolates were screened for salt tolerance ranging from 2 to 10%, a total of 78 isolates were found. Isolates 03, 13 and 31 showed maximum salt tolerance at 10%, in vitro ACC production, phosphate solubilization and IAA production. The three isolates were identified by sequencing the amplified 16S rRNA gene and were found to be Pseudomonas sp. 03 (MW604823), Pseudomonas sp. 13 (MW604824) and Bordetella sp. 31 (MW604826). These microorganisms promoted the germination of radish plants and increased the germination rates for treatments T2, T3 and T4 by 129, 124 and 118% respectively. The beneficial effects of salt tolerant PGPR isolates isolated from saline environments can be new species, used to overcome the detrimental effects of salt stress on plants. The biochemical response and inoculation of the three isolates prove the potential of using these strains as a source of products that can be employed for the development of new compounds proving their potential as biofertilizers for saline environments.

Metal-Resistant PGPR Strain Azospirillum brasilense EMCC1454 Enhances Growth and Chromium Stress Tolerance of Chickpea (Cicer arietinum L.) by Modulating Redox Potential, Osmolytes, Antioxidants, and Stress-Related Gene Expression

Heavy metal stress, including from chromium, has detrimental effects on crop growth and yields worldwide. Plant growth-promoting rhizobacteria (PGPR) have demonstrated great efficiency in mitigating these adverse effects. The present study investigated the potential of the PGPR strain Azospirillum brasilense EMCC1454 as a useful bio-inoculant for boosting the growth, performance and chromium stress tolerance of chickpea (Cicer arietinum L.) plants exposed to varying levels of chromium stress (0, 130 and 260 µM K₂Cr₂O₇). The results revealed that A. brasilense EMCC1454 could tolerate chromium stress up to 260 µM and exhibited various plant growth-promoting (PGP) activities, including nitrogen fixation, phosphate solubilization, and generation of siderophore, trehalose, exopolysaccharide, ACC deaminase, indole acetic acid, and hydrolytic enzymes. Chromium stress doses induced the formation of PGP substances and antioxidants in A. brasilense EMCC1454. In addition, plant growth experiments showed that chromium stress significantly inhibited the growth, minerals acquisition, leaf relative water content, biosynthesis of photosynthetic pigments, gas exchange traits, and levels of phenolics and flavonoids of chickpea plants. Contrarily, it increased the concentrations of proline, glycine betaine, soluble sugars, proteins, oxidative stress markers, and enzymatic (CAT, APX, SOD, and POD) and non-enzymatic (ascorbic acid and glutathione) antioxidants in plants. On the other hand, A. brasilense EMCC1454 application alleviated oxidative stress markers and significantly boosted the growth traits, gas exchange characteristics, nutrient acquisition, osmolyte formation, and enzymatic and non-enzymatic antioxidants in chromium-stressed plants. Moreover, this bacterial inoculation upregulated the expression of genes related to stress tolerance (CAT, SOD, APX, CHS, DREB2A, CHI, and PAL). Overall, the current study demonstrated the effectiveness of A. brasilense EMCC1454 in enhancing plant growth and mitigating chromium toxicity impacts on chickpea plants grown under chromium stress circumstances by modulating the antioxidant machinery, photosynthesis, osmolyte production, and stress-related gene expression.