α-Actinin-4 drives invasiveness by regulating myosin IIB expression and myosin IIA localization.

The mechanisms by which the mechanoresponsive actin crosslinking protein α-actinin-4 (ACTN4) regulates cell motility and invasiveness remain incompletely understood. Here, we show that, in addition to regulating protrusion dynamics and focal adhesion formation, ACTN4 transcriptionally regulates expression of non-muscle myosin IIB (NMM IIB; heavy chain encoded by MYH10), which is essential for mediating nuclear translocation during 3D invasion. We further show that an indirect association between ACTN4 and NMM IIA (heavy chain encoded by MYH9) mediated by a functional F-actin cytoskeleton is essential for retention of NMM IIA at the cell periphery and modulation of focal adhesion dynamics. A protrusion-dependent model of confined migration recapitulating experimental observations predicts a dependence of protrusion forces on the degree of confinement and on the ratio of nucleus to matrix stiffness. Together, our results suggest that ACTN4 is a master regulator of cancer invasion that regulates invasiveness by controlling NMM IIB expression and NMM IIA localization. This article has an associated First Person interview with the first author of the paper.

Nuclear plasticity increases susceptibility to damage during confined migration.

Large nuclear deformations during migration through confined spaces have been associated with nuclear membrane rupture and DNA damage. However, the stresses associated with nuclear damage remain unclear. Here, using a quasi-static plane strain finite element model, we map evolution of nuclear shape and stresses during confined migration of a cell through a deformable matrix. Plastic deformation of the nucleus observed for a cell with stiff nucleus transiting through a stiffer matrix lowered nuclear stresses, but also led to kinking of the nuclear membrane. In line with model predictions, transwell migration experiments with fibrosarcoma cells showed that while nuclear softening increased invasiveness, nuclear stiffening led to plastic deformation and higher levels of DNA damage. In addition to highlighting the advantage of nuclear softening during confined migration, our results suggest that plastic deformations of the nucleus during transit through stiff tissues may lead to bending-induced nuclear membrane disruption and subsequent DNA damage.

Different factors influence naturalization and invasion processes - A case study of Indian alien flora provides management insights.

Why do some alien plants become naturalized, and some naturalized become invasive? Do different factors determine successful naturalization and invasion? Most, if not all, studies addressing these questions have focused either on the part of the invasion continuum or a specific group of alien species. In this study, we aimed to answer these questions for alien plant invasion in India by considering 13 variables related to biogeography, introduction pathways, uses, functional traits, and distribution for 715 species belonging to three invasion categories. We deciphered the variables' influence on successful naturalization and invasion through a structural equation modeling framework implemented as path analyses and translated the findings to management implications. Our study revealed that the invasive aliens had significantly higher naturalized range size, a greater number of uses, and higher specific leaf area than the naturalized and casual aliens. Path analyses revealed that the native and naturalized range sizes, number of uses, and growth form had a direct influence on naturalization success, whereas longer minimum residence time (MRT) facilitated overcoming of the dispersal barrier for naturalized species. Invasion success was directly influenced by the MRT and number of uses, which were further influenced by the number of native congeners and the naturalized range size, respectively. Plant growth forms indirectly influenced invasion success, whereas the native range sizes had indirect effects on successful naturalization and invasion by strongly influencing the size of the naturalized range. Our findings suggested considering species biogeography in the formulation of quarantine measures, imposing policies to discourage the uses and spread of alien plants within the country, and implementing early control measures, especially for the naturalized aliens. The curated dataset used in this study would also provide a ready reference for future research and decision-making towards the management of alien plant invasion in the country.

Insights into endophytic bacterial diversity of rice grown across the different agro-ecological regions of West Bengal, India.

Endophytes have recently garnered importance worldwide and multiple studies are being conducted to understand their important role and mechanism of interaction inside plants. But before we indulge in their functions it is necessary to dig into the microbiome. This will help to get a complete picture of the microbes intrinsic to their host and understand changes in community composition with respect to their habitats. To fulfil this requirement in our study we have attempted to dissect the endophytic diversity in roots of rice plant grown across the various agro-ecological zones of West Bengal by undergoing amplicon analysis of their 16S rRNA gene. Based on the measured environmental parameters agro-ecological zones can be divided into two groups: nutrient dense groups, representing zones like Gangetic, Northern hill and Terai-Teesta zone characterised by soil with higher levels of nitrogen (N) and total organic carbon and nutrient low groups representing Coastal saline, Red-laterite and Vindhyan zone mainly characterised by high electroconductivity and pH. Gammaproteobacteria, Alphaproteobacteria, Bacilli and Bacteroidetes were mostly abundant in nutrient dense sites whereas Clostridia and Planctomycetes were concentrated in nutrient low sites. Few genera (Aeromonas, Sulfurospirillum, Uliginosibacterium and Acidaminococcus) are present in samples cultivated in all the zones representing the core microbiome of rice in West Bengal, while some other genera like Lactococcus, Dickeya, Azonexus and Pectobacterium are unique to specific zone. Hence it can be concluded that this study has provided some insight in to the endophytic status of rice grown across the state of West Bengal.

Remoras pick where they stick on blue whales.

Animal-borne video recordings from blue whales in the open ocean show that remoras preferentially adhere to specific regions on the surface of the whale. Using empirical and computational fluid dynamics analyses, we show that remora attachment was specific to regions of separating flow and wakes caused by surface features on the whale. Adhesion at these locations offers remoras drag reduction of up to 71-84% compared with the freestream. Remoras were observed to move freely along the surface of the whale using skimming and sliding behaviors. Skimming provided drag reduction as high as 50-72% at some locations for some remora sizes, but little to none was available in regions where few to no remoras were observed. Experimental work suggests that the Venturi effect may help remoras stay near the whale while skimming. Understanding the flow environment around a swimming blue whale will inform the placement of biosensor tags to increase attachment time for extended ecological monitoring.

Spatial distribution and risk area assessment of Aphelenchoides besseyi using geostatistical approaches in Giridih district of Jharkhand, India.

Distributed widely across the rice growing regions of India, the rice leaf and bud nematode (Aphelenchoides besseyi Christie 1942) can cause substantial yield loss in rice. Whitening of leaf tips is the characteristics damage symptom of this nematode and therefore it is popularly referred to as the rice white tip nematode (RWTN). While information on the damage severity of RWTN is available from others parts of the country, to date, no information is available from the state of Jharkhand. In order to generate a detailed information on spatial distribution of this nematode and to identify infestation hotspots, extensive field sampling was conducted across the Giridih district of Jharkhand. In total, 163 samples with each sample consisting of 30 randomly chosen panicles from three nearby rice fields were collected across the district. Moran's I spatial autocorrelation test confirmed the presence of significant spatial clustering among the sampling locations. Optimized hotspot analysis found the presence of one significant hotspot in Dumri block and cold spots in adjoining areas of Gawan, Tisri, and Dhanwar blocks. Spatial interpolation techniques like inverse distance weighting (IDW) and ordinary kriging (OK) were employed to predict the population density at unsampled locations. Both IDW and OK resulted into generation of similar kind of maps where population density was found to be higher in Dumri, Giridih, Bengabad and some other pockets of the district. Finally, indicator kriging approach was employed which resulted into identifying both risk and nematode free areas. In risk areas, where the probability of the population density exceeding the economic threshold limit is high, immediate quarantine measures should be taken to prevent further dissemination of contaminated seeds. Our study provided a scientifically based decision method to devise preventive and curative protection measures against A. besseyi, a neglected pest of quarantine significance of rice in India.Distributed widely across the rice growing regions of India, the rice leaf and bud nematode (Aphelenchoides besseyi Christie 1942) can cause substantial yield loss in rice. Whitening of leaf tips is the characteristics damage symptom of this nematode and therefore it is popularly referred to as the rice white tip nematode (RWTN). While information on the damage severity of RWTN is available from others parts of the country, to date, no information is available from the state of Jharkhand. In order to generate a detailed information on spatial distribution of this nematode and to identify infestation hotspots, extensive field sampling was conducted across the Giridih district of Jharkhand. In total, 163 samples with each sample consisting of 30 randomly chosen panicles from three nearby rice fields were collected across the district. Moran's I spatial autocorrelation test confirmed the presence of significant spatial clustering among the sampling locations. Optimized hotspot analysis found the presence of one significant hotspot in Dumri block and cold spots in adjoining areas of Gawan, Tisri, and Dhanwar blocks. Spatial interpolation techniques like inverse distance weighting (IDW) and ordinary kriging (OK) were employed to predict the population density at unsampled locations. Both IDW and OK resulted into generation of similar kind of maps where population density was found to be higher in Dumri, Giridih, Bengabad and some other pockets of the district. Finally, indicator kriging approach was employed which resulted into identifying both risk and nematode free areas. In risk areas, where the probability of the population density exceeding the economic threshold limit is high, immediate quarantine measures should be taken to prevent further dissemination of contaminated seeds. Our study provided a scientifically based decision method to devise preventive and curative protection measures against A. besseyi, a neglected pest of quarantine significance of rice in India.

Abiotic stress regulates expression of galactinol synthase genes post-transcriptionally through intron retention in rice.

MAIN CONCLUSION: Expression of the Galactinol synthase genes in rice is regulated through post-transcriptional intron retention in response to abiotic stress and may be linked to Raffinose Family Oligosaccharide synthesis in osmotic perturbation. Galactinol synthase (GolS) is the first committed enzyme in raffinose family oligosaccharide (RFO) synthesis pathway and synthesizes galactinol from UDP-galactose and inositol. Expression of GolS genes has long been implicated in abiotic stress, especially drought and salinity. A non-canonical regulation mechanism controlling the splicing and maturation of rice GolS genes was identified in rice photosynthetic tissue. We found that the two isoforms of Oryza sativa GolS (OsGolS) gene, located in chromosomes 3(OsGolS1) and 7(OsGolS2) are interspersed by conserved introns harboring characteristic premature termination codons (PTC). During abiotic stress, the premature and mature transcripts of both isoforms were found to accumulate in a rhythmic manner for very small time-windows interrupted by phases of complete absence. Reporter gene assay using GolS promoters under abiotic stress does not reflect this accumulation profile, suggesting that this regulation occurs post-transcriptionally. We suggest that this may be due to a surveillance mechanism triggering the degradation of the premature transcript preventing its accumulation in the cell. The suggested mechanism fits the paradigm of PTC-induced Nonsense-Mediated Decay (NMD). In support of our hypothesis, when we pharmacologically blocked NMD, the full-length pre-mRNAs were increasingly accumulated in cell. To this end, our work suggests that a combined transcriptional and post transcriptional control exists in rice to regulate GolS expression under stress. Concurrent detection and processing of prematurely terminating transcripts coupled to repressed splicing can be described as a form of Regulated Unproductive Splicing and Translation (RUST) and may be linked to the stress adaptation of the plant, which is an interesting future research possibility.

Dopamine promotes cathepsin B-mediated amyloid precursor protein degradation by reactive oxygen species-sensitive mechanism in neuronal cell.

Recent literature suggested an important function of native amyloid precursor protein (APP) as amine oxidase implicating in protection of brain cells from catecholamine-induced toxicity. However, any role of catecholamines on regulation of native APP has not been explored. Here we report that dopamine (DA), one of the most prominent catecholamine neurotransmitters in brain, down-modulates native APP protein in several neuronal cell types. Using SH-SY5Y cells as model, we detected no alteration of transcript expression and unaffected translation suggested that DA might induce APP degradation. We actually found that DA treatment decreased the stability of APP. Lysosomal blockers inhibited DA-induced APP degradation, but specific proteasomal blocker failed to do so. We detected the role of cathepsin B in DA-induced APP degradation by using pharmacological inhibitor and specific siRNA. We also revealed that DA could increase cathepsin B expression at both transcript and protein levels. Using antioxidant N-acetyl cysteine, we detected increased level of reactive oxygen species generation that was found responsible for induced cathepsin B expression by DA and resultant APP degradation. Our study reveals the existence of reciprocal regulation of a catecholamine and an amine oxidase implicating in brain catecholamine homeostasis.

Functional characterization of two myo-inositol-1-phosphate synthase (MIPS) gene promoters from the halophytic wild rice (Porteresia coarctata).

MAIN CONCLUSION: The promoter deletion mutants from second isoform of INO1 (gene-encoding MIPS) from Porteresia coarctata of 932 bp (pPcINO1.2.932) and 793 bp (pPcINO1.2.793) prove to be very efficient as salt/drought stress-inducible promoters, while pPcINO1.2.932 is found to be responsive to cold stress as well. The promoters of the two identified myo-inositol-1-phosphate synthase (INO1) isoforms from salt-tolerant wild rice, Porteresia coarctata (PcINO1.1 and PcINO1.2) have been compared bioinformatically with their counterparts present in the salt-sensitive rice, Oryza sativa. PcINO1.2 promoter was found to be enriched with many abiotic stress-responsive elements, like abscisic acid-responsive elements, MYC-responsive elements, MYB-binding sites, low-temperature stress-responsive elements, and heat-shock elements similar to the ones found in the conserved motifs of the promoters of salt/drought stress-inducible INO1 promoters across Kingdom Planta. To have detailed analysis on the arrangement of cis-acting regulatory elements present in PcINO1 promoters, 5' deletion mutational studies were performed in dicot model plants. Both transient as well as stable transformation methods were used to check the influence of PcINO1 promoter deletion mutants under salt and physiologically drought conditions using ß-glucuronidase as the reporter gene. The deletion mutant from the promoter of PcINO1.2 of length 932 bp (pPcINO1.2.932) was found to be significantly upregulated under drought stress and also in cold stress, while another deletion mutant, pPcINO1.2.793 (of 793 bp), was significantly upregulated under salt stress. P. coarctata being a halophytic species, the high inducibility of pPcINO1.2.932 upon exposure to low-temperature stress was an unexpected result.

Different dehydrins perform separate functions in Physcomitrella patens.

MAIN CONCLUSION: Dehydrins, PpDHNA and PpDHNB from Physcomitrella patens provide drought and cold tolerance while PpDHNC shows antimicrobial property suggesting different dehydrins perform separate functions in P. patens. The moss Physcomitrella patens can withstand extremes of environmental condition including abiotic stress such as dehydration, salinity, low temperature and biotic stress such as pathogen attack. Osmotic stress is inflicted under both cold and drought stress conditions where dehydrins have been found to play a significant protective role. In this study, a comparative analysis was drawn for the three dehydrins PpDHNA, PpDHNB and PpDHNC from P. patens. Our data shows that PpDHNA and PpDHNB play a major role in cellular protection during osmotic stress. PpDHNB showed several fold upregulation of the gene when P. patens was subjected to cold and osmotic stress in combination. PpDHNA and PpDHNB provide protection to enzyme lactate dehydrogenase under osmotic as well as freezing conditions. PpDHNC possesses antibacterial activity and thus may have a role in biotic stress response. Overexpression of PpDHNA, PpDHNB and PpDHNC in transgenic tobacco showed a better performance for PpDHNB with respect to cold and osmotic stress. These results suggest that specific dehydrins contribute to tolerance of mosses under different stress conditions.

The Role of Leaf Volatiles of Ludwigia octovalvis (Jacq.) Raven in the Attraction of Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol.

Implication of matrix metalloproteinases in regulating neuronal disorder.

Neurological disorder is an abnormal condition of the nervous system that occurs due to the structural and biochemical abnormalities of nerves in brain and spinal cord. The nervous system, once exposed, has a limited capacity of self-repair. Neurodegeneration refers to the phenomenon of the structural and functional loss of neurons and the rate of which is accelerated by aging. Recent studies identified the blood brain barrier as hotspot of damage due to neurodegeneration. Depending on the location and severity of damage, the neurons succumb to death through the apoptotic, autophagic and necrotic pathways. The neurological system reorients the structure of neuronal circuits in order to maintain the neuronal plasticity during neurological disorders like Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis etc. Matrix metalloproteinases (MMPs), a family of Zn(2+) dependent endopeptidases play an important role in those neurodegenerative disorders. Recent studies implicated the role of MMPs in acute neuroinflammatory damage as well as in chronic neurodegeneration. The critical function of individual MMPs in tissue repair is also very important. MMPs serve important functions in the central nervous system (CNS) during growth and development. Besides, MMPs are important in neuronal damage in acute and chronic conditions as well as repair processes. Studies reveal that MMPs and the tissue inhibitors of metalloproteinases (TIMPs) play pivotal roles in pathogenesis and recovery of neurons. The expression and activities of MMPs are regulated by signaling molecules, TIMPs, cell surface receptors and transcription factors. In this review, we attempt to elucidate the role of MMPs in neurodegeneration and their functional mechanism in repairing the CNS. We also provide information for the therapeutics in neuronal disorder in the perspective of MMP regulation.

Quantum Monte Carlo calculations of neutron matter with nonlocal chiral interactions.

We present fully nonperturbative quantum Monte Carlo calculations with nonlocal chiral effective field theory (EFT) interactions for the ground-state properties of neutron matter. The equation of state, the nucleon chemical potentials, and the momentum distribution in pure neutron matter up to one and a half times the nuclear saturation density are computed with a newly optimized chiral EFT interaction at next-to-next-to-leading order. This work opens the way to systematic order by order benchmarking of chiral EFT interactions and ab initio prediction of nuclear properties while respecting the symmetries of quantum chromodynamics.

Cadmium-induced oxidative stress tolerance in cadmium resistant Aspergillus foetidus: its possible role in cadmium bioremediation.

Toxic effects of cadmium (Cd) were examined on a cadmium-resistant strain of Aspergillus foetidus isolated from wastewater. The Cd removal potential was analyzed. The results indicated that the strain could tolerate up to 25 mM and 63 mM Cd in liquid and solid Czapek-Dox media, respectively. It efficiently removed Cd from liquid growth media and industrial wastewater by mycelial biosorption. The strain produced oxalic acid for the purpose of Cd bioleaching as confirmed by the presence of cadmium oxalate crystals on the mycelial surface. Intracellular proline contents and the antioxidative enzyme activities increased up to a certain level to detoxify the overproduced free radicals. These data indicate that the strain has inherent mechanisms to grow in Cd contaminated environment, tolerate high Cd doses and high Cd uptake potential which are pre-requisite for acting as a suitable candidate for Cd bioremediation.

Characterization of nimbidiol as a potent intestinal disaccharidase and glucoamylase inhibitor present in Azadirachta indica (neem) useful for the treatment of diabetes.

Azadirachta indica, used in antidiabetic herbal drugs, was reported to contain α-glucosidase inhibitor. Bioassay guided purification characterized the inhibitor as nimbidiol (a diterpenoid), present in root and stem-bark of the tree. Nimbidiol inhibited intestinal (mammalian) maltase-glucoamylase, sucrase-isomaltase, lactase, trehalase and fungal α-glucosidases. Nimbidiol showed a mixed competitive inhibition on intestinal carbohydrases. IC50, Ki and Ki' (µM) were 1.35 ± 0.12, 0.08 ± 0.01, 0.25 ± 0.11, respectively, for maltase-glucoamylase (maltotetraose as substrate). Nimbidiol was more potent inhibitor of isomaltase (IC50 0.85 ± 0.035 µM), lactase (IC50 20 ± 1.33 µM) and trehalase (IC50 30 ± 1.75 µM) than acarbose, voglibose, salacinol, kotalanol and mangiferin. Ki and Ki' values (µM) for intestinal sucrase were 0.7 ± 0.12 and 1.44 ± 0.65, respectively. Development of nimbidiol as an antidiabetic drug appears to be promising because of broad inhibition spectrum of intestinal glucosidases and easy synthesis of the molecule.

Tinospora cordifolia, a novel source of extracellular disaccharidases, useful for human disaccharidase deficiency therapy.

Disaccharide intolerance is the inability to digest certain carbohydrates due to a lack of one or more intestinal disaccharidases (e.g., lactase, maltase, isomaltase and sucrase). Symptoms include diarrhea, abdominal distention and flatulence. Management of the disorder by external enzymes supplementation has not yet been attempted. We report that the medicinal plant Tinospora cordifolia contains substantial amounts of all disaccharidases required for intestinal digestion of carbohydrates. The plant is also a rich source of saccharifying amylase. We recovered (units/100 g fresh stem) amylase: 49,000+500, maltase: 400+50, isomaltase: 130+50, sucrase: 4500+500, acid lactase: 350+30, cellobiase: 35+10 and trehalase: 40+10 by buffer extraction of the blended stem. Crude enzymes in the forms of stem powder, lyophilized aqueous extract and ethanol precipitated protein were found to be stable. Disaccharidases were optimally active at 50 (0) C in the pH range of 4-5. Lactase was an acid lactase similar to the type linked with human lactose intolerance. Enzymes were catalytically stable in the pH range of 2-7 and temperature range of up to 40 (0) C. T. cordifolia enzyme was non-toxic up to a dose of 200 mg protein/kg body weight.

Deciphering structural aspects of reverse cholesterol transport: mapping the knowns and unknowns.

Atherosclerosis is a major contributor to the onset and progression of cardiovascular disease (CVD). Cholesterol-loaded foam cells play a pivotal role in forming atherosclerotic plaques. Induction of cholesterol efflux from these cells may be a promising approach in treating CVD. The reverse cholesterol transport (RCT) pathway delivers cholesteryl ester (CE) packaged in high-density lipoproteins (HDL) from non-hepatic cells to the liver, thereby minimising cholesterol load of peripheral cells. RCT takes place via a well-organised interplay amongst apolipoprotein A1 (ApoA1), lecithin cholesterol acyltransferase (LCAT), ATP binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1), and the amount of free cholesterol. Unfortunately, modulation of RCT for treating atherosclerosis has failed in clinical trials owing to our lack of understanding of the relationship between HDL function and RCT. The fate of non-hepatic CEs in HDL is dependent on their access to proteins involved in remodelling and can be regulated at the structural level. An inadequate understanding of this inhibits the design of rational strategies for therapeutic interventions. Herein we extensively review the structure-function relationships that are essential for RCT. We also focus on genetic mutations that disturb the structural stability of proteins involved in RCT, rendering them partially or completely non-functional. Further studies are necessary for understanding the structural aspects of RCT pathway completely, and this review highlights alternative theories and unanswered questions.

Effects of nZnS vs. nZnO and ZnCl2 on mungbean [Vigna radiata (L.) R. Wilczek] plant and Bradyrhizobium symbiosis: A life cycle study.

Scarce of knowledge of using Zinc (Zn) nanoparticles (NPs) to augment plant growth, Zn availability to plants and its potential toxicity warrants more NPs-plant life cycle studies. The main objectives of this study were to compare nano zinc sulphide (nZnS) with nano zinc oxide (nZnO) and ionic Zn i.e., ZnCl2, as a source of Zn, as well as to establish physiological impact of NPs on growth, yield and symbiosis of mungbean [Vigna radiata (L.) R. Wilczek] plants at different concentrations (0, 0.01, 0.1, 1 and 10 mg kg-1 of soil). In this study, mungbean plants were grown for 60 days (life cycle study) in natural soil infested with Bradyrhizobium. Effects of Zn compounds (nZnS, nZnO and ZnCl2) on plant height, dry biomass, number of nodules per plant, yield and fruit agronomical parameters along with micronutrient assessment were determined. Impact of Zn compounds on Bradyrhizobium-mungbean symbiosis was also unravelled. Results showed that both the NPs, (nZnS and nZnO) were more effective than ZnCl2 in promoting growth and yield up to a critical concentration and above which phytotoxic effects were observed. Both the NPs were more effective than ZnCl2 at increasing fruit Zn content also. Whereas, nZnS treatment was found to be better than nZnO in improving overall plant growth. Bradyrhizobium-mungbean symbiosis was not affected at lower NPs concentrations, while higher concentration revealed toxicity by damaging bacterial morphology and nodule formation. There was no nano specific toxicity found while, ZnCl2 showed relatively more toxicity than both the NPs. The present investigation demonstrated the concept of nano-micronutrient as well as NPs phytotoxicity by understanding NPs-plant interactions in the soil environment.

Appraise potassium chemistry and distribution patterns in tailing soil, India: Through quantity - Intensity relations and multi model statistical methods.

Tailings are waste materials left behind after mineral extraction. Giridih district of Jharkhand, India has the second largest ore of mica mines in the country. This study evaluated the forms of potassium (K+) and quantity-intensity relationships in soils contaminated by tailings around the abundant mica mines. A total of 63 rice rhizosphere soil samples (8-10 cm depth) were collected from agricultural fields near 21 mica mines in the Giridih district at different distances: 10 m (zone 1), 50 m (zone 2), and 100 m (zone 3). The samples were collected to quantify various forms of potassium in the soil and characterize non-exchangeable K (NEK) reserves and Q/I isotherms. The semi-logarithmic release of NEK with continuous extractions suggests a decrease in release over time. Significant values of threshold K+ levels were observed in zone 1 samples. As K+ concentrations increased, the activity ratio (AReK) and its corresponding labile K+ (KL) concentrations decreased. The AReK, KL, and fixed K+ (KX) values were higher in zone 1 [AReK: 3.2 (mol L-1)1/2 × 10-4, KL: 0.058 cmol kg-1, and KX: 0.038 cmol kg-1), except for readily available K+ (K0) for zone 2 (0.028 cmol kg-1). The potential buffering capacity and K+ potential values were higher in zone 2 soils. In zone 1, Vanselow selectivity coefficients (KV) and Krishnamoorthy-Davis-Overstreet selectivity coefficients (KKDO) were higher, while Gapon constants were higher in zone 3. It was found that AReK was significantly correlated with K0, KL, K+ saturation, -ΔG, KV, and KKDO. Different statistical methods such as positive matrix factorization, self-organizing maps, geostatistics, and Monte Carlo simulation approaches were employed to predict soil K+ enrichment, source apportionment, distribution patterns, availability for plants, and contribution to soil K+ maintenance. Thus, this study significantly contributes to understanding K+ dynamics in mica mine soils and operational K+ management.