Mangrove ecosystems in Pattani Bay (Thailand) face increasing anthropogenic threats. In this harsh environment, microbial activity is essential for maintaining ecosystem functioning, productivity, and resilience. This study used amplicon and shotgun metagenomic sequencing to characterize the diversity, abundance, and broad functional potential of mangrove rhizosphere prokaryotic communities across five locations. Physicochemical properties and the accumulation of potentially toxic elements (PTEs) were also analyzed. 16S rRNA gene analysis revealed that Proteobacteria dominated across all locations, followed by Bacteroidota, Acidobacteriota, Actinobacteriota, and Chloroflexi. Across all locations, functional prediction identified 10,145 shared clusters of orthologous genes (COGs) and 5907 shared KEGG orthologs (KOs), predominantly associated with signaling, signal transduction, transport, and metabolism. This pattern indicates a broad yet tightly structured functional potential that underpins the functioning and stability of mangrove ecosystems. Iron and aluminum were among the most concentrated PTEs, and indices of PTE accumulation (geo-accumulation index, contamination factor, and pollution load index) indicated varying contamination risks across locations. Rhizosphere properties, particularly available potassium (Ava_K), magnesium (Mg), and cation exchange capacity (CEC), along with chromium and aluminum, were significant determinants of Thalassospira and SZB85 abundances, suggesting that soil properties and PTEs jointly shaped the composition and assembly of microbial taxa. Meanwhile, electrical conductivity, Ava_K, calcium, Mg, and CEC were major drivers of PTE distribution. Our preliminary findings provide the first dataset on rhizosphere microbial communities and their interactions with environmental properties in Pattani Bay, revealing their broad functional potential and supporting microbe-informed understanding and management of mangrove ecosystem functioning.

To assess fly diversity, abundance, and accumulation of potentially toxic elements (PTEs) in tissue, necrophagous fly communities were collected from open waste bins and landfills in western Thailand. Highest species richness was recorded in Mae Pa and Panlan, each with 11 species; however, Mae Pa exhibited a higher Margalef’s richness index and significantly greater abundance (4,874 individuals) compared to Panlan (314 individuals). Khaothong showed lowest richness with 5 species and a moderate abundance of 944 individuals. Several fly species accumulated considerable PTEs from municipal wastes. Cadmium and zinc were among the most enriched of the PTEs, showing high CF values in the study locations ࣧ 15.25 at Ban Makluea, 15.82 at Pha De and 30.43 at Khaothong, respectively. Principal component analysis indicated that Atherigona spp. and Musca sorbens were highly correlated with cadmium, aluminum, iron, lead and chromium, particularly in Pha De and Mae Pa, respectively. Musca sorbens accumulated the highest concentrations of Cd (278 mg kg−1) and Zn (101 g kg−1) in Pha De. This study suggests that Musca species of necrophagous flies, despite the need of further research for confirmation, are effective as potential bioindicators of Cd and Zn, especially in polluted environments.

Hospital effluent and domestic sewage contain a complex mix of organic pollutants, heavy metals, and pathogens posing environmental and public health risks. Understanding local toxic chemical pollutants and their effects at low concentrations is important to evaluate how they trigger bacterial stress responses like biofilm formation, contributing to antibiotic resistance. The reported study analyzed the chemical composition of wastewater from different sources (hospital, domestic, and institutional) in Aligarh City, India, and evaluated in vitro toxicity and biofilm development in Gram-negative bacteria. Wastewaters collected during 2022–23 were subjected to routine microbiological and physicochemical analysis using standard methods. Phytotoxicity was assessed in Vigna radiata. Biofilms were examined using a microtiter plate assay and microscopy. Physicochemical and microbiological analysis of wastewater revealed site-specific variability in pH, salinity, major ions, and microbial load/coliforms. Cu was the dominant metal in hospital and sewage water (0.068 – 0.079 mg/L⁻1). GC–MS revealed mainly alkanes, phthalates, fatty acids, and esters. DCM extracts from sewage and hospital sources resulted in phytotoxic effects (up to 75

Mangrove ecosystems are facing an increased risk of contamination from toxic elements originating from anthropogenic activities. Bioindicating organisms indigenous to an ecosystem can be used to assess the degree of pollution. Microorganisms are the most applied biota in the evaluation of environmental quality using bioindicators, as they can be evaluated via high-throughput metagenomics sequencing technology. The current review provides a comprehensive report of potentially toxic element (PTE) accumulation, associated bioindicators, and analytical approaches for metals and biota in mangrove ecosystems. The review explores microbial interactions with key environmental variables such as pH, redox potential, and salinity. The behaviors of specific metals and related bioindicators in a typical mangrove ecosystem are presented. The review focuses on microbial bioindicators, their abundance and composition, and their analysis via metagenomics. The current review, with emphasis on mangrove ecosystems, provides a foundation for understanding PTE bioindicators and their interactions with the environment. These findings can support future bioindicator-based programs, including ecosystem health assessments and metagenomics-driven monitoring for conservation and restoration.

The influence of soil amendments (spent coffee grounds, bone meal, sewage sludge) on cadmium (Cd) and zinc (Zn) accumulation and growth performance of marigold (Tagetes erecta L.) varieties - Prime yellow, Twenty yellow and Dragon yellow - was evaluated. X-ray fluorescence was applied to determine the elements in tissues of cross-sectioned stems. Twenty yellow showed the highest percentage tolerance index values (151%) and percentage growth rate in dry biomass (164.2%) in Cd/Zn-amended treatments. The sewage sludge improved soil quality and promoted plant growth and also contributed to high Zn and Cd accumulation in Dragon yellow leaves (221.3 and 57 mg kg(-1), respectively). Dragon yellow variety exhibited potential for Cd phytoextraction potential as indicated by a bioconcentration factor for shoots >1 and translocation factor >1. In Dragon yellow grown in soil amended with BM, Cd and Zn were detected primarily in the epidermis and cortex. This may have resulted from the high P concentration in BM-supplemented soil, which increased co-precipitation of metals with P in epidermal cell walls. The enhancing properties of certain soil amendments can benefit marigold growers, as specific materials were found to support the growth of certain marigold varieties (for example, SS is considerably compatible with the Dragon yellow variety).

Coastal habitats are rich in biodiversity that offer multifunctional ecosystem services. Understanding the roles of microbial dynamics and their distribution patterns is essential for ecosystem quality assessment, which, in turn, helps to decipher associated metagenomic insights. The study integrated 16S rRNA gene-targeted metagenomic data with environmental properties using sediment and seawater from selected coastal habitats (industrial, residential, protected) in Pattani Bay, Thailand. In the industrial-A habitat, both seawater and sediment had lowest mean observed OTUs (operational taxonomic units) of 428.5 and 318.0, and highest mean values were noted in residential sediment (1255.5) and industrial-B seawater (865.0). Despite sediment in the protected site having the second-highest mean OTUs (1240.0), seawater had the second-lowest by 345 OTUs. The dominant prokaryotes were Proteobacteria, Bacteroidota, Campylobacterota, Firmicutes, and Actinobacteriota, accounting for 82.8 % of the total community load. Sediments were enriched with Marinobacter, Sulfurimonas, Thiomicrorhabdus, Sulfurovum, and Rheinheimera genera, while seawaters were dominated by genera Pseudomonas, Shewanella, Bacillus, Rheinheimera, and Flavobacterium, respectively. Key sediment parameters having strong interplay with dominant taxa were soil texture, EC, and OM, and key seawater parameters included salinity, BOD5, and PO43-. PCA identified the influence of these environmental parameters on specific prokaryotic communities. High pollution load index of Industrial-A site may have contributed to lowest prokaryotic diversity, suggesting substantial influence of heavy metals. The current study revealed that prokaryotic composition was sensitive to unique environmental properties induced by local human-driven activities. Hence, all findings will contribute a strong theoretical basis for future coastal ecosystem quality assessments.

Overuse of synthetic antibiotics and the emergence of multidrug resistance (MDR) in ESKAPE bacteria are major clinical concerns on a global scale. ESKAPE bacteria are responsible for most hospital-acquired infections because of their capacity to create robust biofilms. One of the most important targets for medications is biofilm-regulated bacterial pathogenicity. In the Indian medical system, Withania somnifera (L.) Dunal (WS) is an important medicinal plant used to treat illnesses. However, no research has been conducted to assess its antibiofilm potential against MDR pathogens and anti-aging potential. The reported study assessed the potential of WS root aqueous extract against ESKAPE biofilms and linked traits including EPS and alginate production, CSH, swarming and swimming motilities, and production of matrix components (eDNA, eProtein, and eCarbohydrates) of such pathogens in vitro. Concurrently, the root extract was tested for its ability to inhibit enzymes such as tyrosinase, collagenase and elastase contributed to skin aging. The root extract's MIC value against all six ESKAPE pathogens was 2.0mg/mL. Bacterial biofilms were quantified at a sub-MIC value of 1.0mg/mL using a microtiter plate assay and matrix components were evaluated using Dispersin B (DspB) extractant. The sub-MIC concentration significantly reduced biofilm formation and associated characteristics; the utmost inhibition was 59.9% in all six tested pathogens. A likewise pattern of inhibition in matrix components was recorded, and highest reduction was 53.4% in the ESKAPE pathogens. Additionally, the root extract was tested for its anti-aging potential. The sub-MIC concentrations suppressed the three major aging enzymes up to 31.47%. The present study reveals that WS root extract imparts a novel anti-biofilm effect against ESKAPE, as well as offering skin anti-aging potential, for the first time. Thus, WS root could be utilized as a potential herbal remedy against nosocomial infection and aging of skin.

Salinity is among the major environmental factors affecting performance of both crop plants and soil bacterial inoculants beneficial to plant growth. Based on previous screening studies, a novel halotolerant biofilm-forming PGPR strain, namely Pantoea agglomerans-FAP10, was studied for its potential to protect wheat (Triticum aestivum; var. 343) against salinity stress. The ability of this strain to produce biofilms on glass surfaces, 96 well microtiter plates and seedling roots was characterized qualitatively and quantitatively using light and scanning electron microscopy (SEM). The FAP10 strain was tested for performance by inoculating on wheat in a pot-soil system under varied salinity stresses (75, 125, 250 and 500mM NaCl). The FAP10 strain exhibited discrete and multifarious plant growth-promoting traits as well as efficient rhizosphere and root colonization which could sustain wheat growth under salinity stress. The FAP10-induced modifications conferred enhanced plant salinity tolerance by regulating photosynthetic attributes (gs, Ci, E, iWUE, PN, PSII, and Rubisco enzyme activity), antioxidant system (SOD, CAT, GR, APX, GSH, MDA, and proline), and sulfur metabolism (sulfur and cysteine content, ATP-S, and SAT activity), and also sustained soil physicochemical characteristics and hydrolytic enzymes including urease, protease, DHA, ALP, ACP and β glucosidase. The findings of the current study can support future efforts to improve plant salinity tolerance by engineering rhizobacterial biofilms and exploiting the potential of native strains for agricultural applications in stressed environments.

In conventional agricultural practices, pesticides are applied to protect crops from harmful insect pests; however, pervasive usage in high-yield crop systems poses a significant risk to the viability and sustainability of agroecosystems. Agricultural output may be adversely affected by pesticide deposition in the soil as it affects biochemical interactions between plants and soil. Pesticides cause oxidative stress by blocking physiological and biochemical pathways and disrupting the photosynthetic machinery of plants. When exposed to abiotic challenges, plant growth regulators (PGRs) such as auxin, gibberellins, cytokinin and abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), brassinosteroids (BR), and 24-epibrassinolides (EBL) reduce pesticide toxicity by strengthening antioxidant defence mechanisms and enhancing tolerance to stressful conditions. By modulating a variety of physio-biochemical mechanisms, PGRs reduce pesticide toxicity in intact plants. Furthermore, PGRs eliminate reactive oxygen species (ROS) generation by inducing antioxidant enzyme production. Pesticide residues in plant compartments are reduced as a result of PGR-mediated increase in pesticide degradation. This review provides a detailed account of the potential role of PGRs in pesticide detoxification and growth promotion in plants. This work examines several elements of plant pesticidal reactions and assesses how PGRs support plants in tolerating pesticides. The underlying mechanisms during pesticide stress are also discussed. The need for additional study on PGR applications is also emphasized.

Microplastics, plastic particles smaller than 5 mm, pose a significant environmental threat due to their persistence and distribution in aquatic ecosystems. Research on the dynamics of microplastics within freshwater systems, particularly concerning their transport and deposition along river corridors, remains insufficient. This study investigated the occurrence and deposition of microplastics at the water–sediment interface of the White River near Muncie, Indiana. Sediment samples were collected from three sites: White River Woods (upstream), Westside Park (midstream), and Morrow’s Meadow (downstream). The microplastic concentrations varied significantly, with the highest concentration recorded upstream, indicating a strong influence from agricultural runoff. The types of microplastics identified were predominantly fragments (43.1%), fibers (29.6%), and films (27.3%), with fragments being consistently the most abundant at all sampling sites. A polymer analysis with selected particles using Fourier-transform infrared (FTIR) spectroscopy revealed that the most common polymers were polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The hydrodynamic conditions played a crucial role in the deposition and transport of microplastics. The statistical analysis demonstrated a strong positive correlation between the microplastic concentration and flow velocity at the downstream site, suggesting that lower flow velocities contribute to the accumulation of finer sediments and microplastics. Conversely, the upstream and midstream sites exhibited weaker correlations, indicating that other environmental and anthropogenic factors, such as land use and the sediment texture, may influence microplastic retention and transport. This study provides valuable insights into the complex interactions between river dynamics, sediment characteristics, and microplastic deposition in freshwater systems. These findings contribute to the growing body of knowledge on freshwater microplastic pollution and can help guide mitigation strategies aimed at reducing microplastic contamination in riverine ecosystems.

Greenhouse and field studies investigated the phytoextraction potential of soil cadmium (Cd) by Tagetes erecta L., a popular ornamental flower in Asia. The effects of organic fertilizer, cattle manure, and pig manure in supporting plant growth and enhancing Cd uptake were also examined. Plants grown in soil supplemented with pig manure produced greatest biomass (12.8 +/- 1.6 and 11.8 +/- 0.9 g plant(-1) in greenhouse and field experiments, respectively). Plant parts accumulated Cd in the order: shoot > root > flower in all treatments. Furthermore, T. erecta had a high phytoextraction potential as evidenced by translocation factors and enrichment coefficients > 1 for shoots. Marigolds cultivated in Cd-contaminated soil supplemented with organic fertilizer (CdOrg) exhibited Cd concentrations in flowers below the Maximum Permissible Level for consumption (< 0.2 mg kg(-1)), indicating that the edible flowers pose no health risk to humans. The flowers additionally contained significant quantities of total phenolics and phenolic acids, which may indicate their potential as an indicator of Cd-initiated oxidative stress. The phenolic compounds can furthermore function as precursors for manufactured medicinal products by acting as antioxidants and antimicrobials. Application of organic fertilizer and selected organic amendments may have contributed to the greater concentrations of phenolics. The Cd alone treatment resulted in lowest production of bioactive compounds and antioxidant capacity. It is proposed that T. erecta be applied for Cd phytoextraction while enhancing local economies as an ornamental species, and for plant extracts for application of bioactive compounds and antioxidant capacity.

Arsenic (As) is a metalloid pollutant that is extensively distributed in the biosphere. As is among the most prevalent and toxic elements in the environment; it induces adverse effects even at low concentrations. Due to its toxic nature and bioavailability, the presence of As in soil and water has prompted numerous agricultural, environmental, and health concerns. As accumulation is detrimental to plant growth, development, and productivity. Toxicity of As to plants is a function of As speciation, plant species, and soil properties. As inhibits root proliferation and reduces leaf number. It is associated with defoliation, reduced biomass, nutrient uptake, and photosynthesis, chlorophyll degradation, generation of reactive oxygen species, membrane damage, electrolyte leakage, lipid peroxidation and genotoxicity. Plants respond to As stress by upregulating genes involved in detoxification. Different species have adopted avoidance and tolerance responses for As detoxification. Plants also activate phytohormonal signaling to mitigate the stressful impacts of As. This review addresses As speciation, uptake, and accumulation by plants. It describes plant morpho-physiological, biochemical, and molecular changes and how phytohormones respond to As stress. The review closes with a discussion of omic approaches for alleviating As toxicity in plants.

Marigolds (Tagetes erecta L.) were evaluated for phytoremediation potential of cadmium (Cd) and zinc (Zn) as a function of amendment application to soil. Vermicompost (V), biodigestate (Bi), and combined V + Bi (VBi) were used as soil amendments in Zn and Cd co-contaminated soils. Application of soil amendments can alter physicochemical properties of soils, particularly pH, EC, CEC and nutrient concentrations. The VBi treatment resulted in highest percentage growth rate in biomass (52 %) for the Twenty yellow variety of marigold. Also, in the VBi treatment, leaves of Dragon yellow variety exhibited maximal accumulation of Zn and Cd. Flower extracts of Twenty yellow in the V treatment had substantial carotenoid content (71.7 mg L-1) and lowest IC50 value (43.7 mg L-1), thus indicating it had highest DPPH free radical scavenging activity. Dragon yellow exhibited highest values of ferric reducing antioxidant power (FRAP; 2066 mg L-1), total flavonoids content (TFC; 64.1 mg L-1), and total phenolics content (TPC; 50.9 mg L-1). Using X-ray fluorescence (XRF) spectroscopy, the atomic percentages of Zn and Cd in all marigold varieties and treatments showed similar patterns over flower surfaces, seeds, and flower petals in descending order. Prime yellow in the V treatment resulted in higher Zn accumulation in roots (bioconcentration factor of root value) > 1 and translocation factor value < 1, indicating an enhanced ability of the plant for phytostabilization. Application of V altered antioxidant activities and production of bioactive compounds as well as enhanced the excluder potential of Cd and Zn, particularly in the Prime yellow variety. Application of Bi contributed to increased flower numbers, suggesting that floriculturists cultivating marigolds for ornamental purposes may be able to generate revenue in terms of productivity and quality of flowers when marigolds are grown on contaminated land.

Intensive use of chemical pesticides in agriculture poses environmental risks and may have negative impacts on agricultural productivity. The potential phytotoxicity of two chemical pesticides, chlorpyrifos (CPS) and fensulfothion (FSN), were evaluated using Cicer arietinum and Allium cepa as model crops. Different concentrations (0-100 μgmL-1) of both CPS and FSN decreased germination and biological attributes of C. arietinum. High pesticide doses significantly (p ≤ 0.05) caused membrane damage by producing thiobarbituric acid reactive substances (TBARS) and increasing proline (Pro) content. Pesticides elevated ROS levels and substantially increased the superoxide anions and H2O2 concentrations, thus aggravating cell injury. Plants exposed to high pesticide dosages displayed significantly higher antioxidant levels to combat pesticide-induced oxidative stress. Ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) increased by 48%, 93%, 71%, 52% and 94%, respectively, in C. arietinum roots exposed to 100 µgFSNmL-1. Under CLSM, pesticide-exposed C. arietinum and 2',7'-dichlorodihydrofluorescein diacetate (2'7'-DCF) and 3,3'-diaminobenzidine stained roots exhibited increased ROS production in a concentration-dependent manner. Additionally, enhanced Rhodamine 123 (Rhd 123) and Evan's blue fluorescence in roots, as well as changes in mitochondrial membrane potential (ΔΨm) and cellular apoptosis, were both associated with high pesticide dose. Allium cepa chromosomal aberration (CAs) assay showed a clear reduction in mitotic index (MI) and numerous chromosomal anomalies in root meristematic cells. Additionally, a-dose-dependent increase in DNA damage in root meristematic cells of A. cepa and conversion of the super-coiled form of DNA to open circular in pBR322 plasmid revealed the genotoxic potential of pesticides. The application of CPS and FSN suggests phytotoxic and cyto-genotoxic effects that emphasize the importance of careful monitoring of current pesticide level in soil before application and addition at optimal levels to soil-plant system. It is appropriate to prepare both target-specific and slow-release agrochemical formulations for crop protection with concurrent safeguarding of agroecosystems.

Certain plants have been identified with the capability to take up metallic and metal oxide nanoparticles (ENPs), thus suggesting their potential role in phytoremediation. The reported study evaluates the response of two aquatic plants, sedge (Carex rostrata) and cattail (Typha latifolia), on their exposure to Ag, ZnO, TiO2, BiVO4/Pd, and Cu2O/Pd nanoparticles over 15 weeks. Plant physiological responses (chlorophyll content, carbonic anhydrase (CA) activity, leaf area, production of new shoots, and root length) varied according to the plant species and the ENP type. By week 15, sedge treated with BiVO4/Pd ENP had a high chlorophyll content and increased CA activity and leaf area compared to the control. In contrast, cattail had reduced chlorophyll levels and number of new shoots when exposed to exogenously applied BiVO4/Pd. The highest sedge chlorophyll content at week 15 was measured in the mixed-ENPs, Cu2O, and Ag (53.2, 35.8, and 32.7%, respectively, greater than the control). The ZnO ENPs were beneficial for sedge chlorophyll content, cattail shoot production, and root length. The mixed-ENPs treatment imparted positive effects to several sedge properties (CA and new shoots) and cattail (chlorophyll, leaf area, and root length). Additional research is needed to assess the capabilities of different aquatic plant species to tolerate metal-based ENPs for remediation purposes.

Engineered nanoparticles (ENPs) are in demand for numerous industrial, commercial, and domestic applications. Concern has arisen, however, regarding potential adverse environmental impacts from the inadvertent release of ENPs into water bodies. Certain plants have been identified with the capability to absorb metallic ENPs via roots, thus indicating possible application for phytoremediation. The reported study evaluates the potential for two aquatic plant species, viz. cattail (Typha latifolia) and sedge (Carex rostrata) for uptake of Ag, ZnO, TiO2, Pd/BiVO4/BiOBr, and Pd/Cu2O ENPs, each of which were added weekly for 15 weeks. The research was conducted by comparing media doped with metals as nanoparticles and in ionic form. Sedge accumulated greater quantities of Ag, TiO2, and ZnO ENPs in shoots compared with roots. In contrast, cattail roots accumulated proportionally greater concentrations of all ENPs (in particular ZnO, BiVO4, and Cu2O) and ionic metals compared to shoots. Such differences may be attributed, in part, to the root architectures of the two plant species. The translocation factor of ENPs in some treatments (Cu2O, sedge; TiO2, cattail) was >1.0, indicating a potential for phytoextraction. However, the bioconcentration factor for all ENPs was <1.0. Both species hold promise for the phytoextraction of certain ENPs.

Drought stress substantially impedes crop productivity throughout the world. Microbial based approaches have been considered a potential possibility and are under study. Based on our prior screening examination, two distinct and novel biofilm-forming PGPR strains namely Bacillus subtilis-FAB1 and Pseudomonas azotoformans-FAP3 are encompassed in this research. Bacterial biofilm development on glass surface, microtiter plate and seedling roots were assessed and characterized quantitatively and qualitatively by light and scanning electron microscopy. Above two isolates were further evaluated for their consistent performance by inoculating on wheat plants in a pot-soil system under water stresses. Bacterial moderate tolerance to ten-day drought was recorded on the application of individual strains with wheat plants; however, the FAB1 + FAP3 consortium expressively improved wheat survival during drought. The strains FAB1 and FAP3 displayed distinct and multifunctional plant growth stimulating attributes as well as effective roots and rhizosphere colonization in combination which could provide sustained wheat growth during drought. FAB1 and FAP3-induced alterations cooperatively conferred improved plant drought tolerance by controlling physiological traits (gs, Ci, E, iWUE and PN), stress indicators (SOD, CAT, GR, proline and MDA content) and also maintained physico-chemical attributes and hydrolytic enzymes including DHA, urease, ALP, protease, ACP and β glucosidase in the soil. Our findings could support future efforts to enhance plant drought tolerance by engineering the rhizobacterial biofilms and associated attributes which requires in-depth exploration and exploiting potential native strains for local agricultural application.

The potato (Solanum tuberosum) is the fourth most cultivated and consumed crop worldwide. The swelled stolonic region of the plant is economically important due to its considerable quantities of carbohydrates plus modest quantities of minerals and vitamins. Tuber formation is governed by various external and internal factors including light, oxygen concentration, photosynthate availability, phytochromes, transcription factors, and metabolite availability. This review updates and expands upon our current knowledge regarding the involvement of these variables in the tuberization process. Tuber formation starts at the onset of the supportive season under optimal light conditions where phytochromes in leaves sense the signal. The transmittance of the signal results in photosynthate accumulation, phloem loading with sucrose, phloem transport and unloading at the stolonic region, sucrose entry into the tuber cell, and conversion of sucrose to starch, all under the direction of regulatory enzymes. Several genes are associated with tuberization and regulated either positively or negatively. During the course of these cellular micro-reactions, a very fine stolonic tip will ultimately be transformed into a fully matured potato tuber. Tuber formation can be increased by genetic modifications, that further improve tuber yield and quality.

Considering the excessive pesticide pollution in the environment, atrazine (ATZ), butachlor (BCR) and quizalofop-p-ethyl (QUIZ) were selected to assess their toxic effect on Rhodococcus erythropolis PSB-6 (NCBI Accession No. MG028649). MIC values of ATZ, BCR and QUIZ to R. erythropolis were determined to be 100, 200 and 150 mu M, respectively. Biomarker enzymatic assays including LPO, LDH and oxidative stress (CAT) induced by herbicides represented significant (p <= 0.005) toxicity towards strain PSB-6. Herbicide-induced morphological changes viz. aberrant margins; cellular cracking and distortion/damage in R. erythropolis cells were apparent under SEM observation. Furthermore, herbicide-treated and DAPI (4',6-diamidino-2-phenylindole)-stained cells showed concentration-dependent reduction in cellular permeability as revealed under CLSM. Furthermore, herbicides displayed toxicity towards bioactive molecules of PSB-6 in a dose-related manner. Among them, ATZ imparted maximum negative effect, where it reduced the bacterial production of IAA, ACC deaminase and 2, 3-DHBA by 68% (p <= 0.001), 75% (p <= 0.001), and 83% (p <= 0.005), respectively, over control. Additionally, following herbicide exposure, bacterial counts (log(10) CFU mL(-1)) were reduced. Higher concentrations of ATZ and BCR completely reduced the growth patten of strain PSB-6. The current investigation provides an insight into a mechanistic approach of chemical herbicide-induced hazard toward a beneficial soil isolate. Careful monitoring is therefore necessary before agricultural application of pesticides.