Green Synthesis and Characterization of Ginger-Derived Silver Nanoparticles and Evaluation of Their Antioxidant, Antibacterial, and Anticancer Activities.

The efficacy, targeting ability, and biocompatibility of plant-based nanoparticles can be exploited in fields such as agriculture and medicine. This study highlights the use of plant-based ginger nanoparticles as an effective and promising strategy against cancer and for the treatment and prevention of bacterial infections and related disorders. Ginger is a well-known spice with significant medicinal value due to its phytochemical constituents including gingerols, shogaols, zingerones, and paradols. The silver nanoparticles (AgNPs) derived from ginger extracts could be an important non-toxic and eco-friendly nanomaterial for widespread use in medicine. In this study, AgNPs were biosynthesized using an ethanolic extract of ginger rhizome and their phytochemical, antioxidant, antibacterial, and cytotoxic properties were evaluated. UV-visible spectral analysis confirmed the formation of spherical AgNPs. FTIR analysis revealed that the NPs were associated with various functional biomolecules that were associated with the NPs during stabilization. The particle size and SEM analyses revealed that the AgNPs were in the size range of 80-100 nm, with a polydispersity index (PDI) of 0.510, and a zeta potential of -17.1 mV. The purity and crystalline nature of the AgNPs were confirmed by X-ray diffraction analysis. The simple and repeatable phyto-fabrication method reported here may be used for scaling up for large-scale production of ginger-derived NPs. A phytochemical analysis of the ginger extract revealed the presence of alkaloids, glycosides, flavonoids, phenolics, tannins, saponins, and terpenoids, which can serve as active biocatalysts and natural stabilizers of metallic NPs. The ginger extracts at low concentrations demonstrated promising cytotoxicity against Vero cell lines with a 50% reduction in cell viability at 0.6-6 µg/mL. When evaluated for biological activity, the AgNPs exhibited significant antioxidant and antibacterial activity on several Gram-positive and Gram-negative bacterial species, including Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. This suggests that the AgNPs may be used against multi-drug-resistant bacteria. Ginger-derived AgNPs have a considerable potential for use in the development of broad-spectrum antimicrobial and anticancer medications, and an optimistic perspective for their use in medicine and pharmaceutical industry.

Unlocking the Potential of Nano-Enabled Precision Agriculture for Efficient and Sustainable Farming.

Nanotechnology has attracted remarkable attention due to its unique features and potential uses in multiple domains. Nanotechnology is a novel strategy to boost production from agriculture along with superior efficiency, ecological security, biological safety, and monetary security. Modern farming processes increasingly rely on environmentally sustainable techniques, providing substitutes for conventional fertilizers and pesticides. The drawbacks inherent in traditional agriculture can be addressed with the implementation of nanotechnology. Nanotechnology can uplift the global economy, so it becomes essential to explore the application of nanoparticles in agriculture. In-depth descriptions of the microbial synthesis of nanoparticles, the site and mode of action of nanoparticles in living cells and plants, the synthesis of nano-fertilizers and their effects on nutrient enhancement, the alleviation of abiotic stresses and plant diseases, and the interplay of nanoparticles with the metabolic processes of both plants and microbes are featured in this review. The antimicrobial activity, ROS-induced toxicity to cells, genetic damage, and growth promotion of plants are among the most often described mechanisms of operation of nanoparticles. The size, shape, and dosage of nanoparticles determine their ability to respond. Nevertheless, the mode of action of nano-enabled agri-chemicals has not been fully elucidated. The information provided in our review paper serves as an essential viewpoint when assessing the constraints and potential applications of employing nanomaterials in place of traditional fertilizers.

Survival mechanisms of chickpea (Cicer arietinum) under saline conditions.

Salinity is a significant abiotic stress that is steadily increasing in intensity globally. Salinity is caused by various factors such as use of poor-quality water for irrigation, poor drainage systems, and increasing spate of drought that concentrates salt solutions in the soil; salinity is responsible for substantial agricultural losses worldwide. Chickpea (Cicer arietinum) is one of the crops most sensitive to salinity stress. Salinity restricts chickpea growth and production by interfering with various physiological and metabolic processes, downregulating genes linked to growth, and upregulating genes encoding intermediates of the tolerance and avoidance mechanisms. Salinity, which also leads to osmotic stress, disturbs the ionic equilibrium of plants. Survival under salinity stress is a primary concern for the plant. Therefore, plants adopt tolerance strategies such as the SOS pathway, antioxidative defense mechanisms, and several other biochemical mechanisms. Simultaneously, affected plants exhibit mechanisms like ion compartmentalization and salt exclusion. In this review, we highlight the impact of salinity in chickpea, strategies employed by the plant to tolerate and avoid salinity, and agricultural strategies for dealing with salinity. With the increasing spate of salinity spurred by natural events and anthropogenic agricultural activities, it is pertinent to explore and exploit the underpinning mechanisms for salinity tolerance to develop mitigation and adaptation strategies in globally important food crops such as chickpea.

Alleviating Drought Stress in Brassica juncea (L.) Czern & Coss. by Foliar Application of Biostimulants-Orthosilicic Acid and Seaweed Extract.

Agricultural productivity is negatively impacted by drought stress. Brassica is an important oilseed crop, and its productivity is often limited by drought. Biostimulants are known for their role in plant growth promotion, increased yields, and tolerance to environmental stresses. Silicon in its soluble form of orthosilicic acid (OSA) has been established to alleviate deteriorative effects of drought. Seaweed extract (SWE) also positively influence plant survival and provide dehydration tolerance under stressed environments. The present study was conducted to evaluate the efficacy of OSA and SWE on mitigating adverse effects of drought stress on Brassica genotype RH-725. Foliar application of OSA (2 ml/L and 4 ml/L) and SWE of Ascophyllum nodosum (3 ml/L and 4 ml/L) in vegetative stages in Brassica variety RH 725 under irrigated and rainfed condition revealed an increase in photosynthetic rate, stomatal conductance, transpirational rate, relative water content, water potential, osmotic potential, chlorophyll fluorescence, chlorophyll stability index, total soluble sugars, total protein content, and antioxidant enzyme activity; and a decrease in canopy temperature depression, proline, glycine-betaine, H2O2, and MDA content. Application of 2 ml/L OSA and 3 ml/L SWE at vegetative stage presented superior morpho-physiological and biochemical characteristics and higher yields. The findings of the present study will contribute to developing a sustainable cropping system by harnessing the benefits of OSA and seaweed extract as stress mitigators.

Amelioration Effect of Salicylic Acid Under Salt Stress in Sorghum bicolor L.

Salinity is a major abiotic stress, limiting plant growth and agriculture productivity worldwide. Salicylic acid is known to alleviate the negative effects of salinity. The present study demonstrated the impact of SA on sorghum, a moderately salt-tolerant crop, grown for food, fodder, fiber, and fuel. A screen house experiment was conducted using sorghum genotypes Haryana Jowar HJ 513 and HJ 541 under 4 salt levels (0, 5.0, 7.5, and 10.0 dS m-1 NaCl) and 3 SA (0, 25, and 50 mg dm-3) levels with 12 combinations. The leaves were assayed for electrolyte leakage percentage (ELP), i.e., 88.7 % in HJ 541 and 87.2 % in HJ 513, and osmolyte content. Proline content, total soluble carbohydrate content, and glycine betaine content increased considerably. Photosynthetic rate, transpiration rate, and stomatal conductance declined at higher salt levels. The specific enzymatic activities of SOD, CAT, and POX increased 41.1 %, 122.0 %, and 72.8 %, respectively, in HJ 513 under salt stress. Combinations of salt treatment and SA decreased ELP and enhanced osmolyte concentration, rates of gaseous exchange attributes, and also the antioxidant enzymatic activity in salt-stressed leaves. The study established that the specific activity of antioxidative enzymes is enhanced further by addition of SA which may protect the cells from oxidative damage under salt stress, thus mitigating salt stress and enhancing the yield of sorghum. SA can ameliorate the salt stress in plants by affecting the metabolic or physiological frameworks. SA application is an effective management strategy towards mitigating salt stress in order to meet agricultural production and sustainability.

Emerging warriors against salinity in plants: Nitric oxide and hydrogen sulphide.

The agriculture sector is vulnerable to various environmental stresses, which significantly affect plant growth, performance, and development. Abiotic stresses, such as salinity and drought, cause severe losses in crop productivity worldwide. Soil salinity is a major stress suppressing plant development through osmotic stress accompanied by ion toxicity, nutritional imbalance, and oxidative stress. Various defense mechanisms like osmolytes accumulations, activation of stress-induced genes, and transcription factors, production of plant growth hormones, accumulation of antioxidants, and redox defense system in plants are responsible for combating salt stress. Nitric oxide (NO) and hydrogen sulphide (H2 S) have emerged as novel bioactive gaseous signaling molecules that positively impact seed germination, homeostasis, plant metabolism, growth, and development, and are involved in several plant acclimation responses to impart stress tolerance in plants. NO and H2 S trigger cell signaling by activating a cascade of biochemical events that result in plant tolerance to environmental stresses. NO- and H2 S-mediated signaling networks, interactions, and crosstalks facilitate stress tolerance in plants. Research on the roles and mechanisms of NO and H2 S as challengers of salinity is entering an exponential exploration era. The present review focuses on the current knowledge of the mechanisms of stress tolerance in plants and the role of NO and H2 S in adaptive plant responses to salt stress and provides an overview of the signaling mechanisms and interplay of NO and H2 S in the regulation of growth and development as well as modulation of defense responses in plants and their long term priming effects for imparting salinity tolerance in plants.

Repetitive sequences in plant nuclear DNA: types, distribution, evolution and function.

Repetitive DNA sequences are a major component of eukaryotic genomes and may account for up to 90% of the genome size. They can be divided into minisatellite, microsatellite and satellite sequences. Satellite DNA sequences are considered to be a fast-evolving component of eukaryotic genomes, comprising tandemly-arrayed, highly-repetitive and highly-conserved monomer sequences. The monomer unit of satellite DNA is 150-400 base pairs (bp) in length. Repetitive sequences may be species- or genus-specific, and may be centromeric or subtelomeric in nature. They exhibit cohesive and concerted evolution caused by molecular drive, leading to high sequence homogeneity. Repetitive sequences accumulate variations in sequence and copy number during evolution, hence they are important tools for taxonomic and phylogenetic studies, and are known as "tuning knobs" in the evolution. Therefore, knowledge of repetitive sequences assists our understanding of the organization, evolution and behavior of eukaryotic genomes. Repetitive sequences have cytoplasmic, cellular and developmental effects and play a role in chromosomal recombination. In the post-genomics era, with the introduction of next-generation sequencing technology, it is possible to evaluate complex genomes for analyzing repetitive sequences and deciphering the yet unknown functional potential of repetitive sequences.

Significance of satellite DNA revealed by conservation of a widespread repeat DNA sequence among angiosperms.

The analysis of plant genome structure and evolution requires comprehensive characterization of repetitive sequences that make up the majority of plant nuclear DNA. In the present study, we analyzed the nature of pCtKpnI-I and pCtKpnI-II tandem repeated sequences, reported earlier in Carthamus tinctorius. Interestingly, homolog of pCtKpnI-I repeat sequence was also found to be present in widely divergent families of angiosperms. pCtKpnI-I showed high sequence similarity but low copy number among various taxa of different families of angiosperms analyzed. In comparison, pCtKpnI-II was specific to the genus Carthamus and was not present in any other taxa analyzed. The molecular structure of pCtKpnI-I was analyzed in various unrelated taxa of angiosperms to decipher the evolutionary conserved nature of the sequence and its possible functional role.

Sequence analysis of KpnI repeat sequences to revisit the phylogeny of the Genus Carthamus L.

Repetitive DNA sequences constitute a significant proportion of eukaryotic genomes. Knowledge about the distribution of repetitive DNA sequences is necessary in order to gain insights into the organization, evolution and behavior of eukaryotic genomes. Therefore, we used two repetitive DNA sequences pCtKpnI-I and pCtKpnI-II, earlier reported in Carthamus tinctorius L. to study the phylogeny and to revise the taxonomic status of the taxa belonging to the genus. The study unraveled two major lines within the genus Carthamus; one line included all the diploid taxa (2n = 24) and the other line comprised the taxa with 2n = 20 and the polyploid taxa (2n = 44 and 64). The results of the present study will prove useful in molecular breeding for improving some targeted agronomic traits in genus Carthamus.

Evaluation of designer crops for biosafety--a scientist's perspective.

With the advent of transgenic technology, it has become possible to mobilize and express foreign genes into plants and to design crop varieties with better agronomic attributes and adaptability to challenging environmental conditions. Recent advances in transgenic technology have led to concerns about safety of transgenic crops to human and animal health and environment. Biosafety focuses on preventing, minimizing and eliminating risks associated with the research, production, and use of transgenic crops. Food biosafety involves studies of substantial equivalence related to compositional analysis, toxicity and allergenicity. Environmental biosafety involves glasshouse and field trials and study of unintended effects on non-target organisms. Transgenics are characterized at phenotypic and molecular levels for understanding the location of transgene insertion site, ploidy level, copy number, integrated vector sequences, protein expression and stability of the transgene. Various techniques employed for transgene characterization include flow cytometry, southern, northern and western analyses, real-time (qRT) PCR, competitive PCR, FISH, fiber-FISH, DNA micro-arrays, mRNA profiling, 2DE-MS, iTRAQ, FT-MS, NMR, GC-MS, CE-MS and biosensor-based approaches. Evaluation of transgene expression involves the application of integrated phenomics, transcriptomics, proteomics and metabolomics approaches. However, the relevance and application of these approaches may vary in different cases. The elaborate analysis of transgenic crops will facilitate the safety assessment and commercialization of transgenics and lead to global food security for the future.

Agrobacterium-mediated gene transfer in plants and biosafety considerations.

Agrobacterium, the natures' genetic engineer, has been used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer in plants is a highly efficient transformation process which is governed by various factors including genotype of the host plant, explant, vector, plasmid, bacterial strain, composition of culture medium, tissue damage, and temperature of co-cultivation. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques like floral or seedling infilteration, apical meristem transformation, and the pistil drip methods. Monocots have been comparatively difficult to transform by Agrobacterium. However, successful transformations have been reported in the last few years based on the adjustment of the parameters that govern the responses of monocots to Agrobacterium. A novel Agrobacterium transferred DNA-derived nanocomplex method has been developed which will be highly valuable for plant biology and biotechnology. Agrobacterium-mediated genetic transformation is known to be the preferred method of creating transgenic plants from a commercial and biosafety perspective. Agrobacterium-mediated gene transfer predominantly results in the integration of foreign genes at a single locus in the host plant, without associated vector backbone and is also known to produce marker free plants, which are the prerequisites for commercialization of transgenic crops. Research in Agrobacterium-mediated transformation can provide new and novel insights into the understanding of the regulatory process controlling molecular, cellular, biochemical, physiological, and developmental processes occurring during Agrobacterium-mediated transformation and also into a wide range of aspects on biological safety of transgenic crops to improve crop production to meet the demands of ever-growing world's population.