Under changing climate, soil salinity and sodicity is a limiting factor to crop production and are considered a threat to sustainability in agriculture. A number of attempts are being made to develop microbe-based technologies for alleviation of toxic effects of salts. However, the mechanisms of salt tolerance in agriculturally important crops are not fully understood and still require in-depth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed to decipher the microbe-mediated mechanisms of salt tolerance in maize. Endophytic Pseudomonas geniculate MF-84 was isolated from maize rhizosphere and tagged with green fluorescent protein for localization in the plant system. Confocal microphotographs clearly indicate that MF-84 was localized in the epidermal cells, cortical tissues, endodermis and vascular bundles including proto-xylem, meta-xylem, phloem and bundle sheath. The role of P. geniculate MF-84 in induction and bioaccumulation of soluble sugar, proline and natural antioxidants enzymes in maize plant was investigated which lead not only to growth promotion but also provide protection from salt stress in maize. Results suggested that application of P. geniculate MF-84 reduces the uptake of Na⁺ and increases uptake of K⁺ and Ca²⁺ in maize roots indicative of the role of MF-84 in maintaining ionic balance/homeostasis in the plant roots under higher salt conditions. It not only helps in alleviation of toxic effects of salt but also increases plant growth along with reduction in crop losses due to salinity and sodicity.

Plant growth promoting rhizobacteria Pseudomonas aeruginosa strain MF-30 isolated from maize rhizosphere was characterized for several plant growth stimulating attributes. The strain MF-30 was also evaluated for antifungal properties against Rhizoctonia solani causing banded leaf and sheath blight in maize (Zea mays L.) under in vitro conditions and was found to have higher mycelial growth suppression in the culture suspension (67.41%) followed by volatile organic compounds (62.66%) and crude extract (51.20%) in a dual plate assay. The endophytic and epiphytic colonization ability was tested using Green Fluorescent Protein (GFP)-tagging. Visualization through confocal scanning laser microscope clearly indicated that strain MF-30 colonizes the root and foliar parts of the plants. Further, the effects of seed bio-priming with P. aeruginosa MF-30 was evaluated in the induction and bioaccumulation of defense-related biomolecules, enzymes, natural antioxidants, and other changes in maize under pot trial. This not only provided protection from R. solani but also ensured growth promotion under pathogenic stress conditions in maize. The maximum concentration of hydrogen peroxide (H₂O₂) was reported in the root and shoot of the plants treated with R. solani alone (8.47 and 17.50 mmol mg⁻¹ protein, respectively) compared to bioagent, P. aeruginosa MF-30 bio-primed plants (3.49 and 7.50 mmol mg⁻¹ protein, respectively). Effects on total soluble sugar content, total protein, and total proline were also found to enhanced significantly due to inoculation of P. aeruginosa MF-30. The activities of anti-oxidative defense enzymes phenylalanine ammonia lyase (PAL), ascorbate peroxidase, peroxidase, superoxide dismutase, and catalase increased significantly in the plants bio-primed with P. aeruginosa MF-30 and subsequent foliar spray of culture suspension of MF-30 compared to pathogen alone inoculated plants. qRT-PCR analysis revealed that seed bio-priming and foliar application of P. aeruginosa MF-30 significantly increased the expression of PR-1 and PR-10 genes with the simultaneous decrease in the disease severity and lesion length in the maize plants under pathogenic stress conditions. A significant enhancement of shoot and root biomass was recorded in MF-30 bio-primed plants as compared to untreated control (p < 0.05). Significant increase in plant growth and antioxidant content, as well as decreased disease severity in the P. aeruginosa MF-30 bio-primed plants, suggested the possibility of an eco-friendly and economical means of achieving antioxidants-rich, healthier maize plants.

Pharmaceuticals, recognized for their life-saving potential, have emerged as a concerning class of micropollutants in the environment. Even at minute concentrations, chronic exposure poses a significant threat to ecosystems. Various pharmaceutically active micropollutants (PhAMP), including antibiotics, analgesics, and hormones, have been detected in underground waters, surface waters, seawater, sewage treatment plants, soils, and activated sludges due to the absence of standardized regulations on pharmaceutical discharge. Prolonged exposureof hospital waste and sewage treatment facilities is linked to the presence of antibiotic-resistant bacteria. Conventional water treatment methods prove ineffective, prompting the use of alternative techniques like photolysis, reverse osmosis, UV-degradation, bio-degradation, and nano-filtration. However, commercial implementation faces challenges such as incomplete removal, toxic sludge generation, high costs, and the need for skilled personnel. Research gaps include the need to comprehensively identify and understand various types of pharmaceutically active micropollutants, investigate their long-term ecological impact, develop more sensitive monitoring techniques, and explore integrated treatment approaches. Additionally, there is a gap in understanding the socio-economic implications of pharmaceutical pollution and the efficacy of public awareness campaigns. Future research should delve into alternative strategies like phagotherapy, vaccines, and natural substance substitutes to address the escalating threat of pharmaceutical pollution.

Maize (Zea mays) is India’s third-largest grain crop, serving as a primary food source for at least 30% of the population and sustaining 900 million impoverished people globally. The growing human population has led to an increasing demand for maize grains. However, maize cultivation faces significant challenges due to a variety of environmental factors, including both biotic and abiotic stresses. Abiotic stresses such as salinity, extreme temperatures, and drought, along with biotic factors like bacterial, fungal, and viral infections, have drastically reduced maize production and grain quality worldwide. The interaction between these stresses is complex; for instance, abiotic stress can heighten a plant’s susceptibility to pathogens, while an overabundance of pests can exacerbate the plant’s response to environmental stress. Given the complexity of these interactions, comprehensive studies are crucial for understanding how the simultaneous presence of biotic and abiotic stresses affects crop productivity. Despite the importance of this issue, there is a lack of comprehensive data on how these stress combinations impact maize in key agricultural regions. This review focuses on developing abiotic stress-tolerant maize varieties, which will be essential for maintaining crop yields in the future. One promising approach involves the use of Plant Growth-Promoting Rhizobacteria (PGPR), soil bacteria that colonize the rhizosphere and interact with plant tissues. Scientists are increasingly exploring microbial strategies to enhance maize’s resistance to both biotic and abiotic stresses. Throughout the cultivation process, insect pests and microorganisms pose significant threats to maize, diminishing both the quantity and quality of the grain. Among the various factors causing maize degradation, insects are the most prevalent, followed by fungal infections. The review also delves into the latest advancements in applying beneficial rhizobacteria across different agroecosystems, highlighting current trends and offering insights into future developments under both normal and stress conditions.

There is no report available to date on somatic embryogenesis or even callus formation and plant regeneration in Scutellaria baiclensis (Huang qin). Ours is the first report on somatic embryo development in Scutellaria baicalensis. Plant growth regulators Thidiazuron [TDZ: N-phenyl N'- (1,2,3-thidiazol-5-ylurea)], 6-benzyladenine (BA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf, internode, nodal portion, and root explants of Scutellaria baicalensis. The TDZ (4 mg/l) showed the highest percentage of calli-induction frequency in various explants, viz., leaf (42.2%), nodal stem portion (62.9%), and root (63.4%). The TDZ-derived calli were incubated on MS salt + B5 vitamin medium containing glutamine (1.5mM) (MSE) and fortified with various combinations of TDZ, BA, and 2,4-D for induction of somatic embryos. No somatic embryogenesis was recorded in any culture at this stage. On transferring the above friable calli onto hormone-free MSB medium and after 12 days of culture, several globular and heart-shaped embryos appeared over the surface of green compact callus. The mature somatic embryos were dissected out and cultured on hormone-free MS medium for germination. Plantlets were hardened in a growth chamber and, after 30 days, transferred to greenhouse and subsequently to pots and field. There was no morphological difference in plantlets regenerated by this procedure and normal seed-grown plant.