Silent epidemic of silicotuberculosis in India and emergence of multidrug-resistant tuberculosis?

India's projected silica-dust-exposed workers will be 52 million at the end of 2025. Elimination of tuberculosis is also targeted in India by 2025. Scientists in India have already pointed out that unless silicosis is controlled, the said elimination is difficult to achieve. This study evidences an increasing incidence of tuberculosis and multidrug resistant tuberculosis (MDR-TB) with five deaths due to treatment failure among the silica dust-exposed workers compared to their unexposed counterparts. It was also observed that both tuberculosis as well as MDR-TB were directly proportional to the dose and/or duration of silica dust exposure. This means the incidence of MDR-TB is lowest in the unexposed group, moderate in the radiologically negative but silica dust exposed group (subradiological silicosis due to moderate exposure), and highest in the radiologically confirmed silicotic workers (maximally exposed group. Since India has a huge burden of silicosis, they are vulnerable to tuberculosis including multidrug-resistant tuberculosis resulting in the emergence of MDR-TB among the silica dust-exposed workers. This will also lead to a silent epidemic of silicotuberculosis in India shortly. Therefore, it would be important to have tools to quickly detect silicosis cases at an early stage to identify a vulnerable population and adopt an effective intervention measure.

Efficacy of Bacillus Calmette-Guérin in Cancer Prevention and Its Putative Mechanisms.

Bacillus Calmette-Guérin (BCG) is an attenuated strain of Mycobacterium bovis. Although it was developed as a prophylactic vaccine against tuberculosis (TB), researchers have also evaluated it for preventing cancer development or progression. These studies were inspired by the available data regarding the protective effects of microbial infection against cancers and an inverse relationship between TB and cancer mortality. Initial studies demonstrated the efficacy of BCG in preventing leukemia, melanoma and a few other cancers. However, mixed results were observed in later studies. Importantly, these studies have led to the successful use of BCG in the tertiary prevention of non-muscle invasive bladder cancer, wherein BCG therapy has been found to be more effective than chemotherapy. Moreover, in a recently published 60-year follow-up study, childhood BCG vaccination has been found to significantly prevent lung cancer development. In the present manuscript, we reviewed the studies evaluating the efficacy of BCG in cancer prevention and discussed its putative mechanisms. Also, we sought to explain the mixed results of BCG efficacy in preventing different cancers.

Biofilm forming, exopolysaccharide producing and halotolerant, bacterial consortium mitigates salinity stress in Triticum aestivum.

Biofilm and EPS characterization of a rhizobacterial isolate BC-II-20 was done using biophysical techniques. SEM revealed surface morphology of EPS powder to be irregular porous web-like structure. FTIR spectra showed peaks of the polymeric carbohydrate functional groups with probable role in imparting biological properties to EPS. XRD analysis showed signal at 220 (2θ) and confirms its amorphous or semi-crystalline nature. EPS derived from bacterial consortium gradually increased under 200 mM, 400 mM, 600 mM and 800 mM NaCl and SEM-EDAX analysis of EPS showed increase in Na & Cl peaks under the above salt concentrations, depicting EPS-NaCl binding. Triticum aestivum plants under 200 mM NaCl stress with different combinations of treatments showed that bacterial consortium provides tolerance. Under 200 mM salt stress the shoot length was 7.74 cm and total chlorophyll was 4.16 mg g-1Fw of the uninoculated plants whereas inoculated ones were 9.94 cm and 5.62 mg g-1Fw respectively. Under salinity stress, membrane stability index was increased from 47 % to 61 % and electrolyte leakage was decreased to 48 % from 64 %, after inoculation with bacterial consortium. Therefore, consortium comprising of these halotolerant and biofilm forming, EPS producing bioinoculants provides salt tolerance and can be exploited as a sustainable alternative for stress tolerance.

Standardized agronomic practices for mechanical harvesting of the single-harvest garden pea in India.

The field investigations were conducted at Vegetable Research Farm, Department of vegetable Science, Punjab Agricultural University, Ludhiana with the objective to standarize the agronomic practices for mechical harvesting of garden pea. Therefore, effect of different agronomic traits including time of sowing, spacing and sowing method on yield and its attributing traits were studied on single-harvest garden pea. The experiment was laid out in split-plot design with 30 treatments comprising five dates of sowing in main plots and 2 different planting methods (flat and bed) sown at three different spacing in subplots and replicated three times. The bed size was standardized according to front-loading width of the pea combine. Significant interactions were observed between the date of sowing and spacing for a number of pods per plant, green seeds per pod, green pod yield per plant, green pod yield per plot; date of sowing and sowing method for pod length; spacing and sowing method for plant height. However, for all the traits, there was non-significant 3-way interaction. The late sown (20th December) crop resulted in the least number of pods per plant, green seeds per pod, green pod yield per plant and green pod yield per plot which was due to high temperature and low relative humidity conditions at pod development and filling stage. It is concluded that the garden pea cultivar Punjab-89 sown on 5th November at the spacing of 20 × 7.5 cm on beds (bed width of 1.0 m) resulted in significantly highest green pod yield of 12.75 kg/9 m2 in the single harvest. Therefore, the 3 beds of 1 m width can be harvested together with pea combine (because combine has working front width of 3.1 m) results into maximum yield when pea crops is sown on 5th November @ 20 × 7.5 cm spacing.

Vagal sensory neurons mediate the Bezold-Jarisch reflex and induce syncope.

Visceral sensory pathways mediate homeostatic reflexes, the dysfunction of which leads to many neurological disorders1. The Bezold-Jarisch reflex (BJR), first described2,3 in 1867, is a cardioinhibitory reflex that is speculated to be mediated by vagal sensory neurons (VSNs) that also triggers syncope. However, the molecular identity, anatomical organization, physiological characteristics and behavioural influence of cardiac VSNs remain mostly unknown. Here we leveraged single-cell RNA-sequencing data and HYBRiD tissue clearing4 to show that VSNs that express neuropeptide Y receptor Y2 (NPY2R) predominately connect the heart ventricular wall to the area postrema. Optogenetic activation of NPY2R VSNs elicits the classic triad of BJR responses-hypotension, bradycardia and suppressed respiration-and causes an animal to faint. Photostimulation during high-resolution echocardiography and laser Doppler flowmetry with behavioural observation revealed a range of phenotypes reflected in clinical syncope, including reduced cardiac output, cerebral hypoperfusion, pupil dilation and eye-roll. Large-scale Neuropixels brain recordings and machine-learning-based modelling showed that this manipulation causes the suppression of activity across a large distributed neuronal population that is not explained by changes in spontaneous behavioural movements. Additionally, bidirectional manipulation of the periventricular zone had a push-pull effect, with inhibition leading to longer syncope periods and activation inducing arousal. Finally, ablating NPY2R VSNs specifically abolished the BJR. Combined, these results demonstrate a genetically defined cardiac reflex that recapitulates characteristics of human syncope at physiological, behavioural and neural network levels.

Patent landscaping and citation network analysis to reveal the global research trends in biopriming using microbial inoculants: an insight toward sustainable agriculture.

As an alternative to harmful chemical fertilizers and toward fulfilling Sustainable Development Goals (SDGs) of the United Nations, growth promoting rhizobacterial bioinoculants, emerged as potential players. These act in multifunctional ways, including seed colonization, seed germination, stress tolerance and many more, leading to proper growth and development of plants. Biopriming seeds with these beneficial multi-trait microbes is an effective way to introduce them in the soil, and this is an example of bottom-up approach of rhizosphere engineering. Using such sustainable approach is promising and, to investigate and analyze, their research trends are of prime importance. Thus, data were retrieved using Lens and Scopus databases and used for patent landscaping and citation network analysis, respectively. For patent landscaping, documents obtained using customized keyword search were broadly from the past 35 years (1987-2022) and yielded 114 patents which were manually curated in title, abstract and claims (TAC). From the year 2000, interest in this area was observed which further gained momentum from the year 2008, and a maximum peak was observed in the year 2021. Patent profile (filed, granted and published) showed an upward trend during this tenure (1987-2022). In this research article, we aim to provide an overview of current research in this field, identify research hotspots, project future development prospects and make recommendations for further research. Patent landscaping and citation network analysis were used to analyze the recent trends in biopriming approaches using microbial bioinoculants for the first time to identify progress and hotspots in the field of seed priming with PGPRs.

An isolated subcutaneous paraspinal pseudo-tumor-more to it than meets the eye-a case report and review of literature.

A 4-year-old male child presented to us with a paraspinal pseudo-tumor over the mid-back region with pain being his only symptom. On initial ultrasonography, it was presumed to be a nerve sheath tumor, but on an excision biopsy and histopathology, it proved to be a subcutaneous cysticercosis. Furthermore, an MRI of the brain showed a ring enhancing lesion with vasogenic edema, which confirmed the diagnosis of a neurologically symptomless neurocysticercosis. We treated the patient with albendazole and a short course of dexamethasone. There was complete resolution of the painful subcutaneous swelling, and the patient remained neurologically symptomless at all subsequent follow-ups. Resolution of the brain lesions was seen in the 6-month MRI follow-up. Although rare, orthopedic surgeons should consider the possibility of parasitic infections when dealing with small near-asymptomatic soft tissue paraspinal swellings of uncertain etiology. A thorough investigation in such cases can be lifesaving.

TLR4 activation by lysozyme induces pain without inflammation.

Mostly, pain has been studied in association with inflammation, until recent studies which indicate that during bacterial infections, pain mechanisms could be independent of the inflammation. Chronic pain can sustain long after the healing from the injury, even in the absence of any visible inflammation. However, the mechanism behind this is not known. We tested inflammation in lysozyme-injected mice foot paw. Interestingly, we observed no inflammation in mice foot paw. Yet, lysozyme injections induced pain in these mice. Lysozyme induces pain in a TLR4-dependent manner and TLR4 activation by its ligands such as LPS leads to inflammatory response. We compared the intracellular signaling of MyD88 and TRIF pathways upon TLR4 activation by lysozyme and LPS to understand the underlying mechanism behind the absence of an inflammatory response upon lysozyme treatment. We observed a TLR4 induced selective TRIF and not MyD88 pathway activation upon lysozyme treatment. This is unlike any other previously known endogenous TLR4 activators. A selective activation of TRIF pathway by lysozyme induces weak inflammatory cytokine response devoid of inflammation. However, lysozyme activates glutamate oxaloacetate transaminase-2 (GOT2) in neurons in a TRIF-dependent manner, resulting in enhanced glutamate response. We propose that this enhanced glutaminergic response could lead to neuronal activation resulting in pain sensation upon lysozyme injections. Collectively we identify that TLR4 activation by lysozyme can induce pain in absence of a significant inflammation. Also, unlike other known TLR4 endogenous activators, lysozyme does not activate MyD88 signaling. These findings uncover a mechanism of selective activation of TRIF pathway by TLR4. This selective TRIF activation induces pain with negligible inflammation, constituting a chronic pain homeostatic mechanism.

Automatic diagnosis of COVID-19 with MCA-inspired TQWT-based classification of chest X-ray images.

In this era of Coronavirus disease 2019 (COVID-19), an accurate method of diagnosis with less diagnosis time and cost can effectively help in controlling the disease spread with the new variants taking birth from time to time. In order to achieve this, a two-dimensional (2D) tunable Q-wavelet transform (TQWT) based on a memristive crossbar array (MCA) is introduced in this work for the decomposition of chest X-ray images of two different datasets. TQWT has resulted in promising values of peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) at the optimum values of its parameters namely quality factor (Q) of 4, and oversampling rate (r) of 3 and at a decomposition level (J) of 2. The MCA-based model is used to process decomposed images for further classification with efficient storage. These images have been further used for the classification of COVID-19 and non-COVID-19 images using ResNet50 and AlexNet convolutional neural network (CNN) models. The average accuracy values achieved for the processed chest X-ray images classification in the small and large datasets are 98.82% and 94.64%, respectively which are higher than the reported conventional methods based on different models of deep learning techniques. The average accuracy of detection of COVID-19 via the proposed method of image classification has also been achieved with less complexity, energy, power, and area consumption along with lower cost estimation as compared to CMOS-based technology.

Patent intelligence of RNA viruses: Implications for combating emerging and re-emerging RNA virus based infectious diseases.

The recent outbreak of one of the RNA viruses (2019-nCoV) has affected most of the population and the fatalities reported may label it as a modern-day scourge. Active research on RNA virus infections and vaccine development had more commercial impact which leads to an increase in patent filings. Patents are a goldmine of information whose mining yields crucial technological inputs for further research. In this research article, we have investigated both the patent applications and granted patents, to identify the technological trends and their impact on 2019-nCoV infection using biotechnology-related keywords such as genes, proteins, nucleic acid etc. related to the RNA virus infection. In our research, patent analysis was majorly focused on prospecting for patent data related to the RNA virus infections. Our patent analysis specifically identified spike protein (S protein) and nucleocapsid proteins (N proteins) as the most actively researched macromolecules for vaccine and/or drug development for diagnosis and treatment of RNA virus based infectious diseases. The outcomes of this patent intelligence study will be useful for the researchers who are actively working in the area of vaccine or drug development for RNA virus-based infections including 2019-nCoV and other emerging and re-emerging viral infections in the near future.

Chemically Modified Dipeptide Based Hydrogel Supports Three-Dimensional Growth and Functions of Primary Hepatocytes.

A huge shortage of organ donors, particularly in the case of liver, has necessitated the development of alternative therapeutic strategies. Primary hepatocytes (pHCs) transplantation has made a considerable transition from bench to bedside, but the short-term viability and functionality of pHCs in in vitro limit their use for clinical applications. Different cell culture strategies are required to maintain the proliferation of pHCs for extended periods. Here, we described the formation of a hybrid scaffold based on a modified dipeptide for the culture of pHCs. First, the dipeptide (Dp), isoleucine-α,ß-dehydrophenylalanine (IΔF) was synthesized, purified, and fully characterized. IΔF readily formed a highly stable hydrogel, which was also characterized by CD, TEM, and thioflavin T assay. The addition of soluble liver extracellular matrix (sLEM) to the dipeptide readily formed a hybrid scaffold that was characterized by TEM, and its mechanical strength was determined by rheology experiments. The hybrid scaffold was translucent, biocompatible, and proteolytically stable and, with its mechanical strength, closely mimicked that of the native liver. LEM1-Dp matrix exhibited high biocompatibility in the readily available adherent liver cell line Huh7 and primary rat hepatocyte cells (pHCs). pHCs cultured on LEM1-Dp matrix also maintained significantly higher cell viability and an escalated expression of markers related to the hepatocytes such as albumin as compared to that observed in cells cultured on collagen type I (Col I)-coated substrate plate (col-TCTP). Z-stacking of confocal laser microscopy's volume view clearly indicated pHCs seeded on top of the hydrogel matrix migrated toward the Z direction showing 3D growth. Our results indicated that low molecular weight dipeptide hydrogel along with sLEM can resemble biomimetic 3D-like microenvironments for improved pHCs proliferation, differentiation, and function. This hybrid scaffold is also easy to scale up, which makes it suitable for several downstream applications of hepatocytes, including drug development, pHCs transplantation, and liver regeneration.

The role of potassium on drought resistance of winter wheat cultivars under cold dryland conditions: Probed by chlorophyll a fluorescence.

Potassium (K) is an important cation that regulates plant metabolism. Therefore the effect of different concentrations of potassium (0, 75, 150 kg ha-1 K2SO4) on photosynthesis efficiency of three winter wheat cultivars (Baran, Homa, Hashtrud) was investigated during the growing seasons of 2017-18 and 2018-19 under cold dryland conditions in Maragheh, Iran. Accumulation of potassium ion (K+) was observed to be increased with an increase in the concentration of K2SO4. With an increase in K+ the Hashtrud cultivar was observed to have more relative water content (RWC), normalized differential vegetation index (NDVI), and stomatal conductance (gs) than other cultivars. This resulted in a higher grain yield for the Hashtrud cultivar. RWC (R2 = 0.97), NDVI (R2 = 0.96), and gs (R2 = 0.92) had a positive relationship with KUE (grain yield/unit of K fertilizer used), especially in dryer years. K deficiency induced hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentration in plants. The application of K increased superoxide dismutases and reduced abscisic acid, to maintain the plants' stomatal conductance. Chlorophyll a fluorescence (ChlF) and the calculation of double normalized relative variable fluorescence reveal detailed information's about the response of wheat plants to K application under dryland conditions. The application of a high concentration of K (150 kg ha-1 K2SO4) on Hashtrud plants had a beneficial effect on the ChlF efficiency at different OJIP phases (KJ and JI). We found the efficiency of ChlF at the ΔWK-I phase with the values of FV/FO and PIABS improved with the application of 150 kg ha-1 K2SO4 and can be correlated with total yield improvement. These observations indicated that the application of a high concentration of K in stressed conditions for dryland areas could improve photosynthetic efficiency and wheat plant performance.

Does silicon really matter for the photosynthetic machinery in plants ?

Silicon (Si) is known to alleviate the adverse impact of different abiotic and biotic stresses by different mechanisms including morphological, physiological, and genetic changes. Photosynthesis, one of the most important physiological processes in the plant is sensitive to different stress factors. Several studies have shown that Si ameliorates the stress effects on photosynthesis by protecting photosynthetic machinery and its function. In stressed plants, several photosynthesis-related processes including PSII maximum photochemical quantum yield (Fv/Fm), the yield of photosystem II (φPSII), electron transport rates (ETR), and photochemical quenching (qP) were observed to be regulated when supplemented with Si, which indicates that Si effectively protects the photosynthetic machinery. In addition, studies also suggested that Si is capable enough to maintain the uneven swelling, disintegrated, and missing thylakoid membranes caused during stress. Furthermore, several photosynthesis-related genes were also regulated by Si supplementation. Taking into account the key impact of Si on the evolutionarily conserved process of photosynthesis in plants, this review article is focused on the aspects of silicon and photosynthesis interrelationships during stress and signaling pathways. The assemblages of this discussion shall fulfill the lack of constructive literature related to the influence of Si on one of the most dynamic and important processes of plant life i.e. photosynthesis.

Silver Nanoparticle's Toxicological Effects and Phytoremediation.

The advancement in nanotechnology has brought numerous benefits for humans in diverse areas including industry, medicine, and agriculture. The demand in the application of nanomaterials can result in the release of these anthropogenic materials into soil and water that can potentially harm the environment by affecting water and soil properties (e.g., soil texture, pH, organic matter, and water content), plants, animals, and subsequently human health. The properties of nanoparticles including their size, surface area, and reactivity affect their fate in the environment and can potentially result in their toxicological effects in the ecosystem and on living organisms. There is extensive research on the application of nano-based materials and the consequences of their release into the environment. However, there is little information about environmentally friendly approaches for removing nanomaterials from the environment. This article provides insight into the application of silver nanoparticles (AgNPs), as one of the most commonly used nanomaterials, their toxicological effects, their impacts on plants and microorganisms, and briefly reviews the possibility of remediation of these metabolites using phytotechnology approaches. This article provides invaluable information to better understand the fate of nanomaterials in the environment and strategies in removing them from the environment.

Assessment of Prevalence of Dental Caries among School-going Children: A Cross-sectional Study.

BACKGROUND: The background of the study was to assess the prevalence of dental caries among school-going children. MATERIALS AND METHODS: Six thousand eight hundred and ninety school-going children was enrolled. General clinical examination was carried out. Mouth mirror, probe, and explorer were used for carrying out the clinical examination. Over a time span of 6 months, the entire study was completed. All the examiners who performed clinical examination underwent a single-day training program for detecting dental caries. All the participants were seated on straight wooden chairs and were examined clinically. The prevalence of caries was recorded. RESULTS: The prevalence was 26.02%. Among these children with dental caries, 50.25% of the children belonged to the age group of 13-15 years, while the remaining 49.75% of the children belonged to the age group of 9-12 years. Prevalence of dental caries was significantly higher in females (71.11%) in comparison to males. Furthermore, dental caries was significantly more prevalent among participants with toothbrushing frequency of less than once a day (51.20%). CONCLUSION: There is an imperative need for intimating health check-up camps among school-going children.

Influence of different types of explants in chickpea regeneration using thidiazuron seed-priming.

A comparative regeneration of three types of explants prepared from axillary meristems, plumular apices and hypocotyls of chickpea (Cicer arietinum) was carried out using four thidiazuron (TDZ) treatment methods. The first and third ones included the short-term 20 µM TDZ pre-treatment for all three explant types followed by non-supplementation or supplementation of TDZ (4 µM) into the shoot induction medium (SIM), while the second and fourth ones lacked TDZ pre-treatment followed by non-addition or addition of 4 µM TDZ in the SIM. Axillary meristem explants produced the best results with seed pre-treatment using 20 µM TDZ without TDZ in SIM and showed the highest rate of regeneration efficiency (71.33 ± 1.5%) after 20 days. Concurrently, plumular apex explants from TDZ-primed seeds was ranked second, exhibiting a regeneration percentage of 54.33 ± 2.3% in SIM without supplementation of TDZ, whereas explants from hypocotyls generated from seeds subjected to any of the TDZ treatments were not regenerated on any SIMs after 20 days.

Anti-tumor effects of an ID antagonist with no observed acquired resistance.

ID proteins are helix-loop-helix (HLH) transcriptional regulators frequently overexpressed in cancer. ID proteins inhibit basic-HLH transcription factors often blocking differentiation and sustaining proliferation. A small-molecule, AGX51, targets ID proteins for degradation and impairs ocular neovascularization in mouse models. Here we show that AGX51 treatment of cancer cell lines impairs cell growth and viability that results from an increase in reactive oxygen species (ROS) production upon ID degradation. In mouse models, AGX51 treatment suppresses breast cancer colonization in the lung, regresses the growth of paclitaxel-resistant breast tumors when combined with paclitaxel and reduces tumor burden in sporadic colorectal neoplasia. Furthermore, in cells and mice, we fail to observe acquired resistance to AGX51 likely the result of the inability to mutate the binding pocket without loss of ID function and efficient degradation of the ID proteins. Thus, AGX51 is a first-in-class compound that antagonizes ID proteins, shows strong anti-tumor effects and may be further developed for the management of multiple cancers.

Progress in understanding salt stress response in plants using biotechnological tools.

Salinization is a worldwide environmental problem, which is negatively impacting crop yield and thus posing a threat to the world's food security. Considering the rising threat of salinity, it is need of time, to understand the salt tolerant mechanism in plants and find avenues for the development of salinity resistant plants. Several plants tolerate salinity in a different manner, thereby halophytes and glycophytes evolved altered mechanisms to counter the stress. Therefore, in this review article, physiological, metabolic, and molecular aspects of the plant adaptation to salt stress have been discussed. The conventional breeding techniques for developing salt tolerant plants has not been much successful, due to its multigenic trait. The inflow of data from plant sequencing projects and annotation of genes led to the identification of many putative genes having a role in salt stress. The bioinformatics tools provided preliminary information and were helpful for making salt stress-specific databases. The microRNA identification and characterization led to unraveling the finer intricacies of the network. The transgenic approach finally paved a way for overexpressing some important genes viz. DREB, MYB, COMT, SOS, PKE, NHX, etc. conferred salt stress tolerance. In this review, we tried to show the effect of salinity on plants, considering ion homeostasis, antioxidant defense response, proteins involved, possible utilization of transgenic plants, and bioinformatics for coping with this stress factor. An overview of previous studies related to salt stress is presented in order to assist researchers in providing a potential solution for this increasing environmental threat.

Promising Roles of Alternative Medicine and Plant-Based Nanotechnology as Remedies for Urinary Tract Infections.

Urinary tract infections (UTIs) are considered to be the most common infections worldwide, having an incidence rate of 40-60% in women. Moreover, the prevalence of this disorder in adult women is 30 times more than in men. UTIs are usually found in many hospitals and clinical practice; as disorders, they are complicated and uncomplicated; in uncomplicated cases, there is no structural or functional abnormality in the urogenital tract. However, obstruction, retention of urine flow and use of catheters increase the complexity. There are several bacteria (e.g., E. coli, Klebsiella pneumoniae, Proteus vulgaris, etc.) successfully residing in the tract. The diagnosis must not only be accurate but rapid, so early detection is an important step in the control of UTIs caused by uropathogens. The treatment of UTIs includes appropriate antimicrobial therapy to control the infection and kill the causal microbes inside the body. A long-time usage of antibiotics has resulted in multidrug resistance causing an impediment in treatment. Thus, alternative, combinatorial medication approaches have given some hope. Available treatments considered Homeopathic, Ayurvedic, Unani, and other herbal-based drugs. There are new upcoming roles of nanoparticles in combating UTIs which needs further validation. The role of medicinal plant-based nanotechnology approaches has shown promising results. Therefore, there must be active research in phyto-based therapies of UTIs, such as Ayurvedic Biology.

Plant growth promoting Pseudomonas aeruginosa from Valeriana wallichii displays antagonistic potential against three phytopathogenic fungi.

The soil nature and characterstics are directly related to the micro-organisms present, bio-mineralization process, plant type and thus having harmonius and interdependent relationships. Soil bacteria having antagonistic activity against phytopathogens, play an important role in root growth, overall plant growth and also their composition depends upon the plant species. Population explosion across globe has resulted in indiscriminate use of chemical fertilizers, fungicides and pesticides, thus posing serious risk to plant productivity and soil flora. Plant growth promoting rhizobacteria (PGPRs) are considered safer than chemical fertilizers as they are eco-friendly and sustain longer after colonization in rhizospheric soil. PGPRs are preferred as a green choice and acts as a superior biocontrol agents against phytopathogens. In the present study, a potential rhizobacteria, Pseudomonas aeruginosa (isolate-2) was isolated from the rhizosphere of a medicinal plant, Valeriana wallichi. The bacterial isolate exhibited qualitative tests for plant growth promoting determinatives. It was also subjected to in-vitro biocontrol activity against potential phytopathogens viz. Alternaria alternata, Aspergillus flavus and F. oxysporum. The antagonistic efficacy against F. oxysporum was 56.2% followed by Alternaria alternata to be 51.02%. The maximum inhibition of radial growth of F. oxysporum was 69.2%, Alternaria alternata (46.4%) and Aspergillus flavus (15%). The Pseudomonas aeruginosa exhibited plant growth promotion rhizobacterial activity which can be expoited as biofertilizers. This study deals with microbial revitalization strategy and offers promising solution as a biocontrol agent to enhance crop yield. Further, PGPRs research using the interdisciplinary approaches like biotechnology, nanotechnology etc. will unravel the molecular mechanisms which may be helpful for maximizing its potential in sustainable agriculture.