Exploration and Profiling of Potential Thermo-alkaliphilic Bacillus licheniformis and Burkholderia sp. from varied Soil of Delhi region, India and their Plant Growth-Promoting Traits

Soilless cultivation has emerged as a fundamental alternative for large-scale vegetable production because it generates high-quality yields and uses resources efficiently. While plant growth-promoting bacteria (PGPB) are known to enhance growth and physiological aspects in crops grown in soil, their application in soilless cultivation has been relatively less explored. This study aimed to isolate potential PGPBs from soil samples collected from five locations in and around the Delhi-National Capital Region (NCR), India, which were further screened for significant PGPB attributes. Among these, 51 isolated were selected for assessing the impact on Oryza sativa (rice) growth and yield grown on a hydroponic set. The results indicated that isolates AFSI16 and ACSI02 significantly improved the physiological parameters of the plants. For instance, treatment with AFSI16 showed a 23.27% increase in maximum fresh shoot mass, while ACSI02 resulted in a 46.8% increase in root fresh mass. Additionally, ACSI02 exhibited the highest shoot length (34.07%), whereas AFSI16 exhibited the longest root length (46.08%) in O.sativa. Treatment with AFSI16 also led to significant increases in total protein content (4.94%) and chlorophyll content (23.44%), while ACSI02 treatment showed a 13.48% increase in maximum carotenoid content in the leaves. The potential PGPBs were identified through 16S rRNA sequencing, as the two most effective strains, AFSI16 and ACSI02, belonged to thermo-alkaliphilic Bacillus licheniformis and Burkholderia sp., respectively. This study demonstrated the potential of these identified PGPB strains in enhancing crop performance, specifically in soilless cultivation systems.

Importance of Biochar in Agriculture and Its Consequence

Climate change is affecting all four dimensions of food security: food availability, food accessibility, food utilization, and food systems stability. It is also affecting human health, livelihood assets, food production, and distribution channels, as well as changing purchasing power and market flows. Keeping in view, the present chapter is focusing mostly on biochar. Biochar is usually produced by pyrolysis of biomass at around temperature range of 300–600°C. It is under investigation as an approach to carbon sequestration to produce negative carbon emissions. Present agriculture is leading mining of nutrients and reduction in soil organic matter levels through repetitive harvesting of crops. The most widespread solution to this depletion is the application of soil amendments in the form of fertilizers containing the three major nutrients. The nitrogen is considered the most limiting nutrient for plant growth useful for protein builds, structures, hormones, chlorophyll, vitamins, and enzymes. Biochar may be added to soils to improve soil health, improve soil fertility, and sequester carbon. However, the variable application rates, uncertain feedstock effects, and initial soil state provide a wide range of cost for marginally improved yield from biochar additions, which is often economically impracticable. There is a need for further research on optimizing biochar application to improve crop yields

Effects of Zinc Oxide Nanoparticles on Physiological and Anatomical Indices in Spring Barley Tissues

The aim of the present work was to investigate the toxic effects of zinc oxide nanoparticles (ZnO NPs, particle size < 50 nm) on the physiological and anatomical indices of spring barley (Hordeum sativum L.). The results show that ZnO NPs inhibited H. sativum growth by affecting the chlorophyll fluorescence emissions and causing deformations of the stomatal and trichome morphology, alterations to the cellular organizations, including irregularities of the chloroplasts, and disruptions to the grana and thylakoid organizations. There was a lower number of chloroplasts per cell observed in the H. sativum leaf cells treated with ZnO NPs as compared to the non-treated plants. Cytomorphometric quantification revealed that ZnO NPs decreased the size of the chloroplast by 1.5 and 4 times in 300 and 2000 mg/L ZnO NP-treated plants, respectively. The elemental analysis showed higher Zn accumulation in the treated leaf tissues (3.8 and 10.18-fold with 300 and 2000 mg/L ZnO NPs, respectively) than the untreated. High contents of Zn were observed in several spots in ZnO NP-treated leaf tissues using X-ray fluorescence. Deviations in the anatomical indices were significantly correlated with physiological observations. The accumulation of Zn content in plant tissues that originated from ZnO NPs was shown to cause damage to the structural organization of the photosynthetic apparatus and reduced the photosynthetic activities

Coping with the Challenges of Abiotic Stress in Plants: New Dimensions in the Field Application of Nanoparticles

Abiotic stress in plants is a crucial issue worldwide, especially heavy-metal contaminants, salinity, and drought. These stresses may raise a lot of issues such as the generation of reactive oxygen species, membrane damage, loss of photosynthetic efficiency, etc. that could alter crop growth and developments by affecting biochemical, physiological, and molecular processes, causing a significant loss in productivity. To overcome the impact of these abiotic stressors, many strategies could be considered to support plant growth including the use of nanoparticles (NPs). However, the majority of studies have focused on understanding the toxicity of NPs on aquatic flora and fauna, and relatively less attention has been paid to the topic of the beneficial role of NPs in plants stress response, growth, and development. More scientific attention is required to understand the behavior of NPs on crops under these stress conditions. Therefore, the present work aims to comprehensively review the beneficial roles of NPs in plants under different abiotic stresses, especially heavy metals, salinity, and drought. This review provides deep insights about mechanisms of abiotic stress alleviation in plants under NP application

Editorial for Special Issue “Nano-Bioremediation Approaches for Degraded Soils and Sustainable Crop Production”

In recent decades, the global population has rapidly increased, resulting in an increasing demand for food [...

An Innovative Approach to Cleaning Up Organic and Inorganic Contaminations from Soil and Water

Changes in cultivation practices, rapidly increasing anthropogenic activities, and huge industrial waste generation severely affect soil and water ecosystems [...

Role of Engineered Carbon Nanoparticles (CNPs) in Promoting Growth and Metabolism of Vigna radiata (L.) Wilczek: Insights into the Biochemical and Physiological Responses

Despite the documented significance of carbon-based nanomaterials (CNMs) in plant development, the knowledge of the impact of carbon nanoparticles (CNPs) dosage on physiological responses of crop plants is still scarce. Hence, the present study investigates the concentration-dependent impact of CNPs on the morphology and physiology of Vigna radiata. Crop seedlings were subjected to CNPs at varying concentrations (25 to 200 µM) in hydroponic medium for 96 h to evaluate various physiological parameters. CNPs at an intermediate concentration (100 to 150 µM) favor the growth of crops by increasing the total chlorophyll content (1.9-fold), protein content (1.14-fold) and plant biomass (fresh weight: 1.2-fold, dry weight: 1.14-fold). The highest activity of antioxidants (SOD, GOPX, APX and proline) was also recorded at these concentrations, which indicates a decline in ROS level at 100 µM. At the highest CNPs treatment (200 µM), aggregation of CNPs was observed more on the root surface and accumulated in higher concentrations in the plant tissues, which limits the absorption and translocation of nutrients to plants, and hence, at these concentrations, the oxidative damage imposed by CNPs is evaded with the rise in activity of antioxidants. These findings show the importance of CNPs as nano-fertilizers that not only improve plant growth by their slow and controlled release of nutrients, but also enhance the stress-tolerant and phytoremediation efficiency of plants in the polluted environment due to their enormous absorption potential

Small Tech, Big Impact: Agri-nanotechnology Journey to Optimize Crop Protection and Production for Sustainable Agriculture

The world's climate shifts rapidly, leading to increasingly severe and volatile weather, negatively impacting crop yields. To produce long-lasting crops, cutting-edge nanotechnology is applied to agriculture called agri-nanotechnology (ANT), a relatively fresh field of research. ANT aims to help agricultural systems meet the demands for sustainable food production. The inclusion of ANT could transform conventional farming practices by enabling the targeted delivery of biomolecules and the controlled liberation of agrochemicals. Increasing crop yields requires a vaster understanding of the interactions between plants and nanoparticles (NPs) to make them more resistant to environmental stresses and maximize their utilization. Furthermore, ANT is a well-known and highly praised tool that provides various solutions to build modern agricultural practices. In summation, ANT stands as a vanguard in harnessing nanoscale innovations to optimize crop protection and production in a sustainable way

Exploring the Identity and Properties of Two <i>Bacilli</i> Strains and their Potential to Alleviate Drought and Heavy Metal Stress

Naturally available plant growth-promoting rhizobacteria (PGPR) have 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzymes, and are capable of processing the plant-borne ACC by converting it into α-ketobutyrate and ammonia. Thus, the PGPRs help in the depletion of ethylene levels, and enhance abiotic stress tolerance in plants. In the present study, two rhizobacterial strains, i.e., Bacillus cereus and B. haynesii, isolated from Vigna mungo and Phaseolus vulgaris, were used. These strains were taxonomically identified by 16S rDNA sequencing as B. cereus and B. haynesii, with NCBI accession numbers LC514122 and LC 514123, respectively. The phylogeny of these strains has also been worked out based on homology, with data available on NCBI GenBank. The strains were screened for their plant growth-promoting traits, and quantified in the same way. The enzymatic activity and molecular weight of the ACC deaminase obtained from both bacterial strains have also been determined. An in vitro drought tolerance study was done by using PEG 6000. These bacterial strains exhibited higher ACC deaminase activity (~5 to 6 µmol/mL), exopolysaccharide yield (15 to 18 mg/10 mL protein), and indole acetic acid (27–32 µg/mL). These characteristics indicate that the bacterial strains under present study may be helpful in enhancing the drought tolerance of the crops with enhanced yield. Bacillus cereus has been found to be a tolerant strain to As, Ba, and Ni, based on the plate assay method, and so it has the potential to be used as biofertilizer in fields affected by these metals