Curcumin Knoevenagel's Schiff Base as a Promising Stabilizer of G-quadruplex Structure.

G-quadruplex DNA sequences present in the promoter and telomere regions of the genomic sequence are considered therapeutic targets for the treatment of cancer. Curcumin, derived from Curcuma longa, has been known as a quadruplex binder and has a potential role in the apoptosis of cancer cells. Here, we have reported the Schiff base ligand of curcumin synthesized through the condensation of the amino acid L-tryptophan and the knoevenagel derivative of curcumin (4-nitrobenzylidene curcumin (NBC)) as a potential G-quadruplex binder. Thus, spectroscopic and biophysical studies reveal a higher binding affinity of the ligand Sb-NBC towards the promoter and telomere G-quadruplex sequence as compared to the parent NBC. The ligand Sb-NBC highly stabilizes the parallel and hybrid G-quadruplex topologies to 10.5 0C- 6.4 0C. Interestingly, the ligands also exhibit selective cytotoxicity toward cancer cells over normal cells. Taken together, this work provides evidence of the possibility of applying curcumin Schiff base in cancer therapy to regulate oncogene expression in cancer cells.

Curcumin-derivatives as fluorescence-electrochemical dual probe for ultrasensitive detections of picric acid in aqueous media.

We are reporting the two curcumin derivatives, ferrocenyl curcumin (Fc-cur) and 4-nitro-benzylidene curcumin (NBC), as a probe through dual modalities, i.e., fluorescence and electrochemical methods, for the detection of nitro-analytes, such as picric acid (PA). The probes exhibited aggregation-induced enhanced emission (AIEE), and the addition of picric acid (PA) demonstrated good and specific fluorimetric identification of PA in the aggregated state. By using density functional theory (DFT), the mechanism of picric acid's (PA) interactions with the probes was further investigated. DFT studies shows evidence of charge transfer from curcumin derivatives probe to picric acid resulting into the formation of an adduct. The reduction of trinitrophenol (PA) to 2, 4, 6-trinitrosophenol was investigated utilizing a probe-modified glassy carbon electrode (GCE) with a good detection limit of 9.63 ± 0.001 pM and 41.01 ± 0.002 pM, respectively, for Fc-cur@GCE and NBC@GCE, taking into account the redox behavior of the probe. The applicability of the designed sensor has been utilized for real-time application in the estimation of picric acid in several water samples collected from the different source.

Leaf functional traits and resource use strategies facilitate the spread of invasive plant Parthenium hysterophorus across an elevational gradient in western Himalayas.

Parthenium hysterophorus L. (Asteraceae) is a highly prevalent invasive species in subtropical regions across the world. It has recently been seen to shift from low (subtropical) to high (sub-temperate) elevations. Nevertheless, there is a dearth of research investigating the adaptive responses and the significance of leaf functional traits in promoting the expansion to high elevations. The current study investigated the variations and trade-offs among 14 leaf traits (structural, photosynthetic, and nutrient content) of P. hysterophorus across different elevations in the western Himalayas, India. Plots measuring 20 × 40 m were established at different elevations (700 m, 1100 m, 1400 m, and 1800 m) to collect leaf trait data for P. hysterophorus. Along the elevational gradient, significant variations were noticed in leaf morphological parameters, leaf nutrient content, and leaf photosynthetic parameters. Significant increases were observed in the specific leaf area, leaf thickness, and chlorophyll a, total chlorophyll and carotenoid content, as well as leaf nitrogen and phosphorus content with elevation. On the other hand, there were reductions in the amount of chlorophyll b, photosynthetic efficiency, leaf dry matter content, leaf mass per area, and leaf water content. The trait-trait relationships between leaf water content and dry weight and between leaf area and dry weight were stronger at higher elevations. The results show that leaf trait variability and trait-trait correlations are very important for sustaining plant fitness and growth rates in low-temperature, high-irradiance, resource-limited environments at relatively high elevations. To summarise, the findings suggest that P. hysterophorus can expand its range to higher elevations by broadening its functional niche through changes in leaf traits and resource utilisation strategies.

Selection of random coefficients in ordered response models: a framework to detect heterogeneity in household surveys.

This paper develops a Bayesian method to detect heterogeneity in the relationship between covariates and the outcome in models with ordered responses. To this end, we construct an efficient Markov chain Monte Carlo algorithm for a hierarchical Bayesian model that selects random coefficients in ordered models. This method extends an approach for selecting random coefficients in linear mixed models into the ordered setting by adding two enhancements that are relevant to the latter category of models. First, we construct steps to efficiently estimate cut-points by addressing identification and ordering constraints. Second, we develop a framework to evaluate marginal effects that combine the fixed and random effects of each covariate. The marginal effects additionally allow for model uncertainty by averaging across models visited by the selection algorithm. Simulation studies demonstrate that this method detects random effects when they are present, estimates parameters accurately and efficiently samples from the posterior with low autocorrelations across successive draws. On applying this method on data from the survey of consumer expectations, we find clear support for the presence of household-level heterogeneity in relationships between demographic variables, and current as well as expected financial conditions.

Comparative assessment of two biodegradable chelants, S,S-ethylenediamine disuccinic acid and nitrilotriacetic acid, in facilitating Cd remediation by lesser swine cress (Coronopus didymus, Brassicaceae).

Chemically assisted phytoremediation is suggested as an effective approach to amplify the metal-remediating potential of hyperaccumulators. The current study assessed the efficiency of two biodegradable chelants (S,S-ethylenediamine disuccinic acid, EDDS; nitrilotriacetic acid, NTA) in enhancing the remediation of Cd by Coronopus didymus (Brassicaceae). C. didymus growing in Cd-contaminated soil (35-175 mg kg-1 soil) showed increased growth and biomass due to the hormesis effect, and chelant supplementation further increased growth, biomass, and Cd accumulation. A significant interaction with chelants and different Cd concentrations was observed, except for Cd content in roots and Cd content in leaves, which exhibited a non-significant interaction with chelant addition. The effect of the NTA amendment on the root dry biomass and shoot dry biomass was more pronounced than EDDS at all the Cd treatments. Upon addition of EDDS and NTA, bio-concentration factor values were enhanced by ~184-205 and ~ 199-208, respectively. The tolerance index of root and shoot increased over the control upon the addition of chelants, with NTA being better than EDDS. With chelant supplementation, bio-accumulation coefficient values were in the order Cd35 + NTA (~163%) > Cd105 + NTA (~137%) > Cd35 + EDDS (~89%) > Cd175 + NTA (~85%) > Cd105 + EDDS (~62%) > Cd175 + EDDS (~40%). The translocation factor correlated positively (r ≥ 0.8) with tolerance index and Cd accumulation in different plant parts. The study demonstrated that chelant supplementation enhanced Cd-remediation efficiency in C. didymus as depicted by improved plant growth and metal accumulation, and NTA was more effective than EDDS in reclaiming Cd.

Enhanced plasticity and reproductive fitness of floral and seed traits facilitate non-native species spread in mountain ecosystems.

Floral and seed traits, their relationships, and responses to abiotic constraints are considered the key determinants of the invasion success of non-native plant species. However, studies evaluating the pattern of floral and seed traits of non-native species in mountain ecosystems are lacking. In this study, we determined (a) whether the floral and seed traits of native and non-native species show similarity or dissimilarity across elevations in mountains, and (b) whether the non-native species follow different allometric patterns compared with native species. Functional variations between native and non-native species were assessed through floral and seed traits: flower count, flower display area, flower mass, specific flower area, seed count, and seed mass across an elevational gradient. Permanent plots (20 × 20 m) were laid at each 100 m elevation rise from 2000 to 4000 m a.s.l. for sampling of herbaceous plant species. The mean values of floral and seed traits such as flower display area, specific flower area, and seed count were significantly higher for non-native species compared to native species. A significant difference in trait values (flower display area, flower mass, seed count, and seed mass) between non-native species and native species was observed along the elevational gradient, except for flower count and specific flower area. The bivariate relationship revealed non-native species to exhibit a stronger relationship between flower display area ∼ flower mass, and flower display area ∼ seed mass traits than the native species. Non-native species showed enhanced reproductive ability under varying environmental conditions along an elevational gradient in mountain ecosystems. Greater flower display area and seed mass at lower elevations and a stronger overall trait-trait relationship among non-native species implied resource investment in pollinator visualization, flower mass, and seed quality over seed quantity. The study concludes that enhanced plasticity and reproductive fitness of floral and seed traits would consequently aid non-native species to adapt, become invasive, and displace native species in mountain ecosystems if the climatic barriers acting on non-native species are reduced with climate change.

Assessment of natural low molecular weight organic acids in facilitating cadmium phytoextraction by Lepidium didymus (Brassicaceae).

The present study examined the ability of three naturally occurring low molecular weight organic acids (tartaric, TA; citric, CA; and oxalic, OA) to improve the efficiency of cadmium (Cd) phytoextraction in Lepidium didymus L. (Brassicaceae). The plants were grown in soil containing three different concentrations, i.e., 35, 105, and 175 mg kg-1, of total Cd and 10 mM of TA, CA, and OA. After 6 weeks, plant height, dry biomass, photosynthetic traits, and metal accumulation were determined. All three organic chelants significantly increased the Cd accumulation in L. didymus plants; however, the greatest accumulation was seen with TA (TA > OA > CA). In general, Cd accumulation was the highest in the roots, followed by the stems, and the leaves. Highest BCFStem was observed upon the addition of TA (7.02) and CA (5.90) at Cd35, compared to Cd-alone (3.52) treatment. The BCF was the highest in the stem (7.02) and leaves (3.97) under Cd35 treatment supplemented with TA. The BCFRoot in the plants under different chelant treatments were in the following order: Cd35 + TA (~ 100) > Cd35 + OA (~ 84) > Cd35 + TA (~ 83). The stress tolerance index and translocation factor (root-stem) were maximal at Cd175 with TA and OA supplementation, respectively. The study concludes that L. didymus could be a viable option for Cd-remediation projects, and the addition of TA improved its phytoextraction efficiency.

Invasive Cirsium arvense displays different resource-use strategies along local habitat heterogeneity in the trans-Himalayan region of Ladakh.

Climate change and anthropogenic pressures have resulted in a significant shift in the invasion susceptibility and frequency of non-native species in mountain ecosystems. Cirsium arvense (L.) Scop. (Family: Asteraceae) is an invasive species that spreads quickly in mountains, especially in the trans-Himalayan region of Ladakh. The current study used a trait-based approach to evaluate the impact of local habitat heterogeneity (soil physico-chemical properties) on C. arvense. Thirteen plant functional traits (root, shoot, leaf, and reproductive traits) of C. arvense were studied in three different habitat types (agricultural, marshy, and roadside). Functional trait variability in C. arvense was higher between, than within habitats (between different populations). All the functional traits interacted with habitat change, except for leaf count and seed mass. Soil properties strongly affect C. arvense's resource-use strategies across habitats. The plant adapted to a resource-poor environment (roadside habitat) by conserving resources and to a resource-rich environment (agricultural and marshy land habitat) by acquiring them. The ability of C. arvense to use resources differently reflects its persistence in introduced habitats. In summary, our study shows that C. arvense invades different habitats in introduced regions through trait adaptations and resource-use strategies in the trans-Himalayan region.

Mechanistic aspects of binding of telomeric over parallel G-quadruplex with novel synthesized Knoevenagel condensate 4-nitrobenzylidene curcumin.

The introduction of small ligands to stabilise G-quadruplex DNA structures is a promising method for developing anti-cancer drugs. It is challenging to stabilise the G-quadruplex structure, which can take on a variety of topologies and is known to inhibit specific biological processes. To achieve this, 4-nitrobenzylidene curcumin (NBC), the Knoevenagel condensate of curcumin, was synthesized and characterized. The interaction of 4-nitrobenzylidene curcumin with parallel (c-MYC) and hybrid (H-telo) G-quadruplex structures was studied by circular dichroism (CD) spectroscopy, UV-thermal melting, differential scanning calorimetry (DSC), absorption spectroscopy, fluorescence spectroscopy and docking studies. The outcome demonstrates that, in a K+ -rich solution, the ligand NBC can stabilise the parallel c-MYC and hybrid H-telo G-quadruplex structures by 5°C. The absorption and fluorescence studies show that the ligand NBC binds to c-MYC and H-telo with affinities of 0.3 × 106 M-1 and 0.6 × 106 M-1 , respectively. The ligand interacts with the terminal G-quartet of the quadruplex structure via intercalation and the groove mode of binding, well supported by docking studies as well. NBC has more potent antioxidant activity as compared to the curcumin and 4-nitro benzaldehyde. It was also found to have higher cytotoxic activity towards cell line such as HeLa and MCF-7, while less cytotoxic for healthy Vero cells. Overall, the results show that the Knoevenagel product of curcumin can work better as a G-quadruplex binder and could be used as a possible treatment.

Comparison of synthetic and organic biodegradable chelants in augmenting cadmium phytoextraction in Solanum nigrum.

This study focused to enhance the cadmium (Cd) phytoextraction efficiency in Solanum nigrum by applying four biodegradable chelants (10 mM)-ethylene glycol tetraacetic acid (EGTA), ethylenediamine disuccinate (EDDS), nitrilotriacetic acid (NTA), and citric acid (CA), when grown in Cd-spiked soil (12 and 48 mg kg-1). Plant height, dry biomass, photosynthetic traits, and metal accumulation varied significantly with Cd and chelant treatments. Cadmium-toxicity resulted in reduction of plant growth and photosynthetic physiology, whereas chelant supplementation alleviated the toxic effect of Cd and increased its accumulation. Tolerance index value increased with addition of chelants in the order: EGTA (1.57-1.63) >EDDS (1.39-1.58) >NTA (1.14-1.50) >CA (1-1.22) compared with Cd (0.46-1.08). Transfer coefficient of root increased with supplementation of EGTA (3.40-3.85), EDDS (3.10-3.40), NTA (2.60-2.90), and CA (1.85-2.29), over Cd-alone (1.61-1.63). Similarly, translocation factor was also increased upon addition of EGTA (0.52-0.73), EDDS (0.35-0.81), NTA (0.38-0.75), and CA (0.53-0.54), compared with Cd-alone (0.36-0.59). Maximum Cd removal (67.67% at Cd12 and 36.05% at Cd48) was observed with supplementation of EGTA. The study concludes that the supplementation of EGTA and EDDS with S. nigrum can be employed as an efficient and environmentally safe technique for reclamation of Cd-contaminated soils.

Apart from the selection of a good hyperaccumulator, the choice of chelant (biodegradable/non-biodegradable) is an important aspect for the successful phytoextraction of metals from contaminated soil. We reported for the first time the potential of ethylene glycol tetraacetic acid (EGTA; a biodegradable chelant) in enhancing Cd phytoextraction by Solanum nigrum. Comparative appraisal of metal extraction efficiency of biodegradable chelants at low (12 mg kg⁻¹) and high (48 mg kg⁻¹) Cd dose depicted that EGTA performed better than EDDS, NTA, and CA (other biodegradable chelants). EGTA supplementation did not induce toxicity in plants; rather it improved metal accumulation, morphology, and photosynthetic physiology.

Enhanced antioxidant and cytotoxic activity of ferrocenyl-substituted curcumin via stabilization of promoter c-MYC silencer element.

We are reporting a successful attachment of ferrocenyl moiety at the active methylene carbon atom of ß-diketone of curcumin via Knoevenagel condensation reaction, to utilize the optimum selectivity toward biological targets. The formation of ferrocenyl curcumin (i.e., Fc-cur) has been confirmed by 1H NMR, 13C NMR, and FT-IR spectra analysis. Further, circular dichroism (CD) spectroscopy, thermal denaturation, absorption, and fluorescence spectroscopy have been used to understand the association of ligand (i.e., Fc-cur) with G-quadruplex. Based on these analysis, the binding mechanism of the ligand i.e., Fc-cur to the parallel and hybrid topology present in different G-quadruplex has been proposed. Further, the binding and modes of the interaction of Fc-cur with Pu27 c-MYC silencer element and H-telo G-quadruplex have unravelled selective and stronger binding via intercalation with the parallel topology of c-MYC G-quadruplex rather than the hybrid topology of H-telo quadruplex. The manifestation of better antioxidant activity of Fc-cur has been demonstrated by showing a stronger radical scavenging capability than pristine curcumin. The cytotoxicity analysis of the proposed ligand i.e., Fc-cur against Vero and HeLa cells have clearly reflected the nontoxicity toward Vero cells and quite effective against the HeLa cells which reduces the cancer cells more effectively than the already reported for curcumin.Communicated by Ramaswamy H. Sarma.

Biodegradable chelant-metal complexes enhance cadmium phytoextraction efficiency of Solanum americanum.

Toxic contaminants (metals and metal-containing compounds) are accumulating in the environment at an astonishing rate and jeopardize human health. Remarkable industrial revolution and the spectacular economic growth are the prime causes for the release of such toxic contaminants in the environment. Cadmium (Cd) is ranked the 7th most toxic compound by the Agency for Toxic Substances and Disease Registry (USA), owing to its high carcinogenicity and non-biodegradability even at miniscule concentration. The present study assessed the efficiency of four biodegradable chelants [nitrilotriacetic acid (NTA), ethylenediamine disuccinate (EDDS), ethylene glycol tetraacetic acid (EGTA), and citric acid (CA)] and their dose (5 mM and 10 mM) in enhancing metal accumulation in Solanum americanum Mill. (grown under 24 mg Cd kg-1 soil) through morpho-physiological and metal extraction parameters. Significant variations were observed for most of the studied parameters in response to chelants and their doses. However, ratio of root and shoot length, and plant height stress tolerance index differed non-significantly. The potential of chelants to enhance Cd removal efficiency was in the order - EGTA (7.44%) > EDDS (6.05%) > NTA (4.12%) > CA (2.75%). EGTA and EDDS exhibited dose-dependent behavior for Cd extraction with 10 mM dose being more efficient than 5 mM dose. Structural equation model (SEM) depicted strong positive interaction of metal extraction parameters with chelants (Z-value = 11.61, p = 0.001). This study provides insights into the importance of selecting appropriate dose of biodegradable chelants for Cd extraction, as high chelant concentration might also result in phytotoxicity. In the future, phytoextraction potential of these chelants needs to be examined through field studies under natural environmental conditions.

ß-Pinene alleviates arsenic (As)-induced oxidative stress by modulating enzymatic antioxidant activities in roots of Oryza sativa.

Rice (Oryza sativa L.) is a highly consumed staple crop worldwide, but abiotic/heavy metal stresses acting on the plant cause reduction in yield and quality, thereby impacting global food security. In the present study, we examined the effect of ß-pinene against Arsenic (As)-induced oxidative damage vis-à-vis regulation of activities of enzymatic antioxidants in roots of O. sativa. Effect of As (50 µM), ß-pinene (10 µM; ß-10) and As + ß-10 treatments on root length, shoot length, As accumulation, lipid peroxidation (as malondialdehyde [MDA] content), hydrogen peroxide (H2O2) accumulation, and activities of lipoxygenase (LOX) and enzymatic antioxidants such as ascorbate peroxidase (APX), guaiacol peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) was determined. Exposure of As caused a decline in root and shoot length, and enhancement in As accumulation, lipid peroxidation, and activities of enzymatic antioxidants. However, supplementation of ß-10 (i.e., As + ß-10 treatments) led to an increase in root and shoot length. Treatment with As + ß-10 resulted in a decline in As accumulation, H2O2 content, and MDA content; however, the effect on LOX activity was non-significant, as compared to control. Similarly, with As + ß-10 treatment a reduction in the activities of APX, GPX, GR, SOD, and CAT was observed as compared with As-alone treatment. Pearson's correlation matrix exhibited strong negative correlation between reactive oxygen species (ROS) and root/shoot length, whereas a strong positive correlation was observed between antioxidant enzymes and ROS. The present study demonstrated that ß-pinene significantly ameliorates As-induced oxidative stress and provides tolerance to O. sativa against As-induced toxicity, and thus offer an option of As-mitigation using environment friendly natural plant products. However, to gain insights into the function of ß-pinene in modulating As-induced oxidative damage in plants, further field investigations and exploration of its mechanism of action are needed.

Bridging the gap: linking morpho-functional traits' plasticity with hyperaccumulation.

Plant species exhibiting heavy metal tolerance are instrumental in phytoremediation of metalliferous sites. Most of the time, variations in plant functional traits (PFTs) are overlooked while identifying hyperaccumulators. However, investigating morphological, physiological, and phenological variations can contribute to our knowledge about stress tolerance, and aid in identifying potential hyperaccumulators. In the present study, we investigated variation in morpho-functional traits in Solanum nigrum, a known hyperaccumulator, under lead (Pb) stress. Twenty-one PFTs including 9 above-ground (leaf count, leaf area, specific leaf area, leaf dry matter content, leaf thickness, leaf dry mass, shoot length, stem dry mass, stem diameter), 3 below-ground (root length, root dry mass, and root diameter), 4 reproductive (flower bud count, fruit count, flower count, and fruit dry mass), and 5 photosynthetic traits (total chlorophyll, total carotenoid, chlorophyll a, chlorophyll b, and photosynthetic efficiency) under varying Pb concentrations (500-2000 mg kg-1) were assessed. Pillai's trace test (MANOVA) depicted significant variations in above-ground, below-ground, and photosynthetic traits, whereas reproductive traits did not vary significantly with progressive metal concentration. However, most of the studied traits except flower count, fruit dry mass, and chlorophyll b varied significantly under Pb stress. The study depicts that enhanced PFT's plasticity enables S. nigrum to grow in Pb-contaminated soil effectively without impacting plant fitness. Plasticity of morpho-functional traits, therefore, establishes itself as a resourceful approach in successful identification of phytoremediation capacity of a plant.

Amelioration potential of ß-pinene on Cr(VI)-induced toxicity on morphology, physiology and ultrastructure of maize.

Heavy metals' amassment in the soil environment is a threat to crop and agricultural sustainability and consequentially the global food security. For achieving enhancement of crop productivity in parallel to reducing chromium (Cr) load onto food chain demands continuous investigation and efforts to develop cost-effective strategies for maximizing crop yield and quality. In this context, we investigated the amelioration of Cr(VI) toxicity through ß-pinene in experimental dome simulating natural field conditions. The protective role of ß-pinene was determined on physiology, morphology and ultrastructure in Zea mays under Cr(VI) stress (250 and 500 µM). Results exhibited a marked reduction in the overall growth (shoot and root length and dry matter) of Z. mays plants subjected to Cr(VI) stress. Photosynthetic pigments (chlorophyll and carotenoids) were evidently reduced, and there was a loss of membrane integrity. Supplementation of ß-pinene (100 µM), however, declined the toxicity induced by Cr(VI). Interestingly, Cr-tolerant abilities were improved in relation to plant growth, photosynthetic pigments and membrane integrity with the combined treatment of Cr(VI) and ß-pinene. ß-Pinene also reduced the root-mediated uptake of Cr(VI) and translocation to shoots. Moreover, significant ultrastructural damages recorded in roots and shoots under Cr(VI) stress were partially reverted upon addition of ß-pinene. Our analyses revealed that ß-pinene mitigates Cr(VI) toxicity in Z. mays, either by membrane stabilization or serving as a barrier to the uptake of Cr from soil. Thus, exogenous supply of ß-pinene can be an effective alternative to mitigate Cr toxicity in soil. However, it is deemed essential to investigate further the responses throughout the life cycle of the plant on ß-pinene supplementation under natural conditions.

Salicylic acid pre-treatment modulates Pb2+-induced DNA damage vis-à-vis oxidative stress in Allium cepa roots.

The current study investigated the putative role of salicylic acid (SA) in modulating Pb2+-induced DNA and oxidative damage in Allium cepa roots. Pb2+ exposure enhanced free radical generation and reduced DNA integrity and antioxidant machinery after 24 h; however, SA pre-treatment (for 24 h) ameliorated Pb2+ toxicity. Pb2+ exposure led to an increase in malondialdehyde (MDA) and hydrogen peroxide (H2O2) accumulation and enhanced superoxide radical and hydroxyl radical levels. SA improved the efficiency of enzymatic antioxidants (ascorbate and guaiacol peroxidases [APX, GPX], superoxide dismutases [SOD], and catalases [CAT]) at 50-µM Pb2+ concentration. However, SA pre-treatment could not improve the efficiency of CAT and APX at 500 µM of Pb2+ treatment. Elevated levels of ascorbate and glutathione were observed in A. cepa roots pre-treated with SA and exposed to 50 µM Pb2+ treatment, except for oxidized glutathione. Nuclear membrane integrity test demonstrated the ameliorating effect of SA by reducing the number of dark blue-stained nuclei as compared to Pb2+ alone treatments. SA was successful in reducing DNA damage in cell exposed to higher concentration of Pb2+ (500 µM) as observed through comet assay. The study concludes that SA played a major role in enhancing defense mechanism and protecting against DNA damage by acclimatizing the plant to Pb2+-induced toxicity.

Isolation and characterization of a novel hydrocarbonoclastic and biosurfactant producing bacterial strain: Fictibacillus phosphorivorans RP3.

In this study, an indigenous novel hydrocarbonoclastic (kerosene and diesel degrading) and biosurfactant producing strain Fictibacillus phosphorivorans RP3 was identified. The characteristics of bacterial strain were ascertained through its unique morphological and biochemical attributes, 16S rRNA sequencing, and phylogenetic analysis. The degradation of hydrocarbons by F. phosphorivorans RP3 was observed at Day 7, Day 10 and Day 14 of the experimental duration. GC-FID chromatograms demonstrated a significant increase in hydrocarbon degradation (%) with progressing days (from 7 to 14). The bacterium exhibited capability to utilize and degrade n-hexadecane (used for primary screening) and petroleum hydrocarbons (kerosene and diesel; by ≥ 90%). With increase in the number of experimentation days, the optical density of the culture medium increased, whereas pH declined (became acidic) for both Kerosene and Diesel. Absence of resistance to routinely used antibiotics makes it an ideal candidate for future field application. The study is, thus, significant in view of toxicological implications of hydrocarbons and their degradation using environmentally safe techniques so as to maintain ecological and human health.

Patterns of plant communities along vertical gradient in Dhauladhar Mountains in Lesser Himalayas in North-Western India.

Mountains are definitely the most rugged, yet frail resources and biodiversity-rich regions of the world. Environmental variables directly affect species composition, growth patterns, and the ecosystem resulting in a drastic change in the vegetation composition along ascending elevations. The present study investigated vegetation composition, nestedness, and turnover in plant communities along a vertical gradient (2000 to 4000 m) in Dhauladhar Mountains, Lesser Himalayas, India. We determined how α-diversity pattern and nestedness-related processes or turnover (ß-diversity) causes dissimilarity in plant communities' composition along the vertical gradient. Overall, 21 permanent plots (20 × 20 m2) at every 100 m interval from 2000 to 4000 m were established. A sampling of shrubs and herbaceous species was done by marking sub-plots of 5 × 5 m2 and 1 × 1 m2, respectively, within permanent plots. We observed an inverted hump-shaped pattern for evenness index (E), a unimodal hump-shaped pattern for Shannon index (H'), Margalef's richness index, and ß-Whittaker (ßw) diversity, and mild-hump-shaped pattern for Simpson index (λ) across the elevational gradient. Turnover (ßsim) and the nestedness-resultant component of ß-diversity (ßsne) significantly differed across the elevational gradient. The observed ß-diversity patterns revealed that the species replacement rate was less in the mid-altitude communities as compared to lower and higher altitude communities. It was largely attributed to the ecotonic nature of mid-altitudes, which benefited mid-elevational communities rather than low or high altitude communities. Besides lower altitudes, the increased human interference has led to disturbance and subsequent homogenization of flora across the mid-altitudes. With respect to this, the present study signifies the need for preserving the mid-altitudinal communities, without undermining the importance of conserving the low and high altitude communities.