Deciphering Azadirachta indica (Neem) Gum Microbiome using Metagenomic Approaches

Indian lilac or neem (Azadirachta indica) is found in tropical and subtropical regions of the Indian subcontinent. Each part of the tree is a source of various phytochemicals. Neem gum is an exudate from mature parts of the plant stem. Biochemically, it has an acidic pH range (5–6) and is composed of monosaccharides, saponins, phenols, and tannins. This study aimed to elucidate the diversity of neem gum-associated microflora through high throughput metagenomics approach using 16S rRNA variable region sequencing. The bacterial community of neem gum was dominated by Firmicutes (~82%), Proteobacteria (~18%), and Actinobacteria (~0.02%). Among the genera, Lactococcus was found to be the most dominant bacterium. The predominance of Lactococcus in neem gum is probably due to its acidic nature, which provides a suitable microenvironment for its proliferation. In addition, Lactococcus and beneficial microorganisms such as Pseudomonas, Burkholderia, Pantoea, Klebsiella, and Methylobacterium were also present in the gum. This study highlights the fact that neem gum can be exploited as a unique source of microorganisms for biotechnological and agricultural applications

Potential applications of blue green algae

13-20Blue green algae (BGA) possess immense morphological and metabolic diversity and can be used in economic developmentand environment management like wastewater treatment, land reclamation, production of fine chemicals, atmospheric fixation ofnitrogen, production of methane fuel, conversion of solar energy, therapeutic functions and so on. This review presents applicationsof BGA in agriculture, food and industry

Plant Growth-promoting and Biocontrol Potential of Selected Cyanobacteria from Stress Environment

Cyanobacteria are photosynthetic microorganisms and produce large number of diverse bioactive compounds. In the present study plant growth promotion and antifungal activities of fourteen cyanobacteria strains have been studied against selected phytopathogens. Among screened isolates highest production of IAA was found in Chroococcidiopsis cubana HC1 (102.9 µg/ml) when supplemented with 0.3 mg/mL tryptophan. Co-inoculation of C. cubana (HC1) and Tolypothrix sp. (RC1) were evaluated for plant growth promoting potential on rice (Rajendra Sweta) plant which showed enhanced root (20.7±1.0 cm) and shoot length (11.4±1.3 cm) as well as increased number of forks (36.0±1.0) as compared to control seedlings. Among fourteen isolates eight cyanobacterial isolates showed zone of inhibition against selected phytopathogens. Tolypothrix sp RC1 and Nostoc sp. SK1 showed highest rate of inhibition (50%) against Ralstonia solanaceram while Pseudoanabaena sp. RD1 showed highest inhibition rate (52%) against Sclerotium rolfsi. Nostoc sp. HC2 found to be highest inhibition (61%) against Fusarium oxysporum. The cyanobacteria reported in this study have immense potential for biocontrol against fungal plant pathogens and plant growth promoting ability which enhances crop growth. Cyanobacterial isolates obtained from the study could be worthy in sustainable agriculture due to dual advantages of biocontrol as well as plant growth promotion

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Not AvailableBackground: Conventional plant DNA isolation methods are complex, time consuming and require technical expertise. These limitations were overcome using the DNA isolation kits which, however significantly add to the research costs. Hence the present study was aimed to develop a high throughput, rapid and inexpensive method of PCR ready DNA template preparation from plant materials. Methods: Concentration of SDS in lysis buffer, amount of starting material, period and temperature for lysis were optimized for obtaining PCR ready templates from plant materials. The method was tested using RAPD and ITS specific primers for different plant species like rice, wheat, mustard, pea, soybean, pigeonpea, tomato, maize, march lilly, bougainvillea, Indian blanket flower, nerium, petunia, purple pirouette petunia, moses-in-the-cradle, golden cane palm, duranta, periwinkle, chrysanthemum and two xerophytes viz. Dipterygium glaucum and Crotaleria burhia. SSR markers RM18398 and RM26108 showed successful amplification in rice varieties Improved Pusa Basmati 1 and KS Dev 12. The effectiveness of the method was tested using fresh as well as 1 year old tissues. The storability of the lysate was also tested. Results: In this report, we developed a novel method called rapid high throughput template preparation (rHTTP) method to prepare PCR ready DNA templates. Most striking feature of this technique is that it can be done anywhere where water can be boiled by any means. Using rHTTP method, PCR ready templates can be prepared in just 10 min. Robust and reproducible amplification for all the test plants were recorded with RAPD, plant ITS primers and SSR markers following this method. rHTTP methods works well for both fresh as well as old plant tissues. The lysates had a shelf life of 1 month when stored at 4 °C and 3 days when stored at room temperature. Conclusions: rHTTP method has several advantages over the other protocols like ease of execution, no requirement of tissue grinding/liquid nitrogen/hazardous chemicals and above all, equally effective for both fresh and old samples. Using this method, costs per prep comes down ~ 10–50 times as compared to most commercial kits. This method can be used for on-field experiments like molecular diagnostics, varietal identification etc.Not Availabl

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Not AvailableIn this study, we screened 26 bioactive compounds present in various spices for activity against SARS-CoV-2 using molecular docking. Results showed that piperine, present in black pepper had a high binding affinity (-7.0 kCal/mol) than adenosine monophosphate (-6.4 kCal/mol) towards the RNA-binding pocket of the nucleocapsid. Molecular dynamics simulation of the docked complexes confirmed the stability of piperine docked to nucleocapsid protein as a potential inhibitor of the RNA-binding site. Therefore, piperine seems to be potential candidate to inhibit the packaging of RNA in the nucleocapsid and thereby inhibiting the viral proliferation. This study suggests that consumption of black pepper may also help to combat SARS-CoV-2 directly through possible antiviral effects, besides its immunomodulatory functions.Not Availabl

Multifarious Plant Growth-Promoting Rhizobacterium Enterobacter sp. CM94-Mediated Systemic Tolerance and Growth Promotion ofChickpea (Cicer arietinum L.) under Salinity Stress

Background: Chickpea is one of the most important leguminous crops and its productivity is significantly affected by salinity stress. The use of ecofriendly, salt-tolerant, plant growth-promoting rhizobacteria (PGPR) as a bioinoculant can be very effective in mitigating salinity stress in crop plants. In the present study, we explored, characterized, and evaluated a potential PGPR isolate for improving chickpea growth under salt stress. Methods: A potential PGPR was isolated from rhizospheric soils of chickpea plants grown in the salt-affected area of eastern Uttar Pradesh, India. The isolate was screened for salt tolerance and characterized for its metabolic potential and different plant growth-promoting attributes. Further, the potential of the isolate to promote chickpea growth under different salt concentrations was determined by a greenhouse experiment. Results: A rhizobacteria isolate, CM94, which could tolerate a NaCl concentration of up to 8% was selected for this study. Based on the BIOLOG carbon source utilization, isolate CM94 was metabolically versatile and able to produce multiple plant growth-promoting attributes, such as indole acetic acid, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophore, hydrogen cyanide (HCN), and ammonia as well as solubilized phosphate. A polyphasic approach involving the analysis of fatty acid methyl ester (FAME) and 16S rRNA gene sequencing confirmed the identity of the isolate as Enterobacter sp. The results of greenhouse experiments revealed that isolate CM94 inoculation significantly enhanced the shoot length, root length, and fresh and dry weight of chickpea plants, under variable salinity stress. In addition, inoculation improved the chlorophyll, proline, sugar, and protein content in the tissues of the plant, while lowering lipid peroxidation. Furthermore, isolate CM94 reduced oxidative stress by enhancing the enzymatic activities of superoxide dismutase, catalase, and peroxidase compared to in the respective uninoculated plants. Conclusions: Overall, the results suggested that using Enterobacter sp. CM94 could significantly mitigate salinity stress and enhance chickpea growth under saline conditions. Such studies will be helpful in identifying efficient microorganisms to alleviate salinity stress, which in turn will help, to devise ecofriendly microbial technologies

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Not AvailablePhosphate solubilization is an important and widely studied plant growth promoting trait exhibited by many bacteria. Pyrroloquinoline quinone (PQQ), a redox cofactor of methanol and glucose dehydrogenases has been well established as essential for phosphate solubilization. PQQ operon has been well studied in growth promoting rhizobacteria like Pseudomonas spp., Gluconobacter oxydans, Klebsiella pneumoniae, etc. However, the role of PqqB is quite ambiguous as its functional role has been contradicted in many studies. In the present study, we selected Pseudomonas stutzeri - a well-known P solubilizing bacterium as a representative species of the Pseudomonas genus on the basis of phylogenetic and statistical analyses of PqqB proteins. A 3 D model was generated for this protein. Docking of PqqB with PQQ showed good interaction with a theoretical binding affinity of -7.4 kcal/mol. On the other hand, docking of PqqC with 3a-(2-amino-2-carboxy-ethyl)-4,5-dioxo-4,5,6,7,8,9-hexahydro-quinoline-7,9-dicarboxylic acid (AHQQ, immediate precursor of PQQ) showed strong interaction (-10.4 kcal/mol) but the same was low with PQQ (-6.4 kcal/mol). Molecular dynamic simulation of both the complexes showed stable conformation. The binding energy of PqqB-PQQ complex (-182.710 ± 16.585 kJ/mol) was greater than PqqC-PQQ complex (-166.114 ± 12.027 kJ/mol). The results clearly indicated that kinetically there is a possibility that after cyclization of AHQQ to PQQ by PqqC, PQQ can be taken up by PqqB and transported to periplasm for the oxidation of glucose. To the best of our knowledge, this is the first attempt to understand the biological role of PqqB on the basis of molecular interactions and dynamics.Not Availabl

Genetic diversity and antifungal activities of the genera Streptomyces and Nocardiopsis inhabiting agricultural fields of Tamil Nadu, India

Actinomycetes receives much attention as plant-beneficial bacteria due to their distinct morpho-physiological, plant growth promoting and antifungal properties. Among the actinomycetes, members of the genus Streptomyces are of specific interest due to their metabolic versatility and ubiquity. The diversity of Streptomyces in different crop fields of Tamil Nadu has not been explored early. In this study, we explored phylogenetic diversity, morphological heterogeneity, and antifungal properties of cultivable actinomycetes isolated from the rhizosphere and bulk soils of different crops collected from 20 distinct districts of Tamil Nadu. A total of 65 actinomycetes were isolated from 40 soil samples including rhizosphere and bulk soils of different crops, and their diversity was analyzed using the 16S rRNA gene sequence. They were then characterized for cultural characteristics and antifungal activity against four fungal strains Fusarium udum, Fusarium oxysporum f.sp. ciceri, Macrophomina phaseolina and Sclerotium rolfsii. Out of the 65 isolates sequenced, 45 were found to be closely related to Streptomyces spp. while the remaining 20 showed similarities with Nocardiopsis spp. Cultural characterization on four different ISP media showed immense diversity among the members of the genera Streptomyces and Nocardiopsis. The strains of Streptomyces spp. and Nocardiopsis spp. showed varying levels of antifungal activity with all strains found antagonistic against both Fusarium udum and Fusarium oxysporum f.sp. ciceris. All the strains obtained in this study have been accessioned at the National Agriculturally Important Microbial Culture Collection (NAIMCC) to increase the database of characterized strains belonging to these two genera in the collection

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Not AvailableCold shock proteins (CSPs) are greatly conserved family of structurally related DNA binding proteins which are produced during temperature drift. A 213 bp long cspA gene was cloned and sequenced from Pseudomonas koreensis P2 in the present study. The expression analysis of the cspA showed 2.5 folds increase in the mRNA level at 15 C while the expression was almost on par at 30 C and 5 C indicating its role in moderately low temperature. In silico analyses of the gene showed that the gene codes for 7.69 kDa protein which was phylogenetically very similar to CspA present in Pseudomonads. Amino acid composition of the CspA from P. koreensis was different from that of mesophilic Pseudomonas and tiny/small amino varied significantly between CspA of cold adaptive and mesophilic species. The CspA from P. koreensis P2 contained RNP motifs involved in binding of DNA and RNA. Phylogenetic analyses revealed that the CspA protein of P. koreensis P2 was more close to CspA of distant subgroups of Pseudomonas like P. fluorescens and P. putida subgroup indicating a possible intra-specific gene transfer.The authors gratefully acknowledge the financial assistance under network project ‘Application of Microorganisms Agriculture and Allied Sectors (AMAAS)’ and ‘‘CRP Genomics’’ from Indian Council of Agricultural Research (ICAR), India. i