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Plant growth-promoting rhizobacteria (PGPR) represent a set of microorganisms that play significant role in improving plant growth and controlling the phytopathogens. Unpredictable performance after the application of PGPR has been observed when these were shifted from in-vitro to in-vivo conditions due to the prevalence of various abiotic stress conditions. During growing period, the potato crop is subjected to a combination of biotic and abiotic stresses. Rhizoctonia solani, a soil-borne plant pathogen, causes reduced vigor and yield of potato crop worldwide. In the current study, multi-stress-tolerant rhizobacterial strain, Bacillus subtilis PM32, was isolated from field-grown potato with various plant growth promoting (PGP) traits including zinc and potassium solubilization, biological nitrogen fixation, ammonia and siderophore, as well as extracellular enzyme productions (cellulase, catalase, amylase, protease, pectinase, and chitinase). The strain PM32 exhibited a distinct potential to support plant growth by demonstrating production of indole-3-acetic acid (102.6 μM/mL), ACC-deaminase activity (1.63 μM of α-ketobutyrate/h/mg protein), and exopolysaccharides (2.27 mg/mL). By retarding mycelial growth of R. solani the strain PM32 drastically reduced pathogenicity of R. solani. The strain PM32 also suppressed the pathogenic activity significantly by impeding mycelial expansion of R. solani with inhibition co-efficient of 49.87. The B. subtilis PM32 also depicted significant tolerance towards salt, heavy metal (Pb), heat and drought stress. PCR based amplification of ituC and acds genes coding for iturin and ACC-deaminase activity respectively indicated potential of strain PM32 for lipopeptides production and ACC deaminase enzyme activity. Results of both in-vitro and pot experiments under greenhouse conditions depicted the efficiency of B. subtilis PM32 as a promising bio-control agent for R. solani infection together with enhanced growth of potato plants as deciphered from biomass accumulation, chlorophyll a, b, and carotenoid contents. Therefore, it was envisioned that application of indigenous multi-stress tolerant PGPR may serve to induce biotic and abiotic stress tolerance in crops/plants for pathogen control and sustainable global food supply.

Plant growth-promoting bacteria (PGPB), possess multifarious beneficial traits and facilitate plant growth by both direct and indirect mechanisms under hostile conditions. The objective of the current study was to evaluate the potential application of 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase) producing plant-growth promoting endophyte bacterium (PGPEB) Kocuria rhizophila strain 14ASP (National Center for Biotechnology Information; NCBI) Accession Number: LFIY00000000.1) heavy metals and salt resistance tolerance under hostile environment. The in vitro study was conducted to evaluate plant growth promotion characteristics, heavy metal and salt resistance of the K. rhizophila under normal and stressful environments. The strain 14ASP revealed the plant-growth promoting and of AAC deaminase activities under abiotic stress environment. K. rhizophila showed significant tolerance against different heavy metals on LB (Luria Ber-tani) agar plates and broth medium supplemented with cadmium (Cd), (50 mg L−1), cooper (Cu), (50 mg L−1), nickel (Ni), (50 mg L−1), lead (Pb), (200 mg L−1) and chromium (Cr) (500 mg L−1), respectively. It also exhibited population density (OD = 0.31–0.45) at different concentrations of sodium chloride (NaCl) (0% 5%, 10%, and 15% w/v) in LB medium. The draft genome of strain 14ASP is 2.6 Mb and was assembled into 183 contigs with 2689,1 bp and a G + C content of 70% and 1,882,646 bp, encoded 2409 protein, 8 rRNAs and 46 tRNAs. Genome analysis identified genes, involved in hydrocarbon metabolism, heavy metal tolerance, biofilm formation, Indole Acetic Acid (IAA) and siderophore biosynthesis. All these properties were confirmed by in silico and draft genome analysis.

The rhizosphere is a narrow and dynamic region of plant root-soil interfaces, and it's considered one of the most intricate and functionally active ecosystems on the Earth, which boosts plant health and alleviates the impact of biotic and abiotic stresses. Improving the key functions of the microbiome via engineering the rhizosphere microbiome is an emerging tool for improving plant growth, resilience, and soil-borne diseases. Recently, the advent of omics tools, gene-editing techniques, and sequencing technology has allowed us to unravel the entangled webs of plant-microbes interactions, enhancing plant fitness and tolerance to biotic and abiotic challenges. Plants secrete signaling compounds with low molecular weight into the rhizosphere, that engage various species to generate a massive deep complex array. The underlying principle governing the multitrophic interactions of the rhizosphere microbiome is yet unknown, however, some efforts have been made for disease management and agricultural sustainability. This review discussed the intra- and inter- microbe-microbe and microbe-animal interactions and their multifunctional roles in rhizosphere microbiome engineering for plant health and soil-borne disease management. Simultaneously, it investigates the significant impact of immunity utilizing PGPR and cover crop strategy in increasing rhizosphere microbiome functions for plant development and protection using omics techniques. The ecological engineering of rhizosphere plant interactions could be used as a potential alternative technology for plant growth improvement, sustainable disease control management, and increased production of economically significant crops.

Agriculture is directly linked to human life, providing food for survival and health. It is threatened by a number of challenges, such as climate change, resource depletion, and abiotic stresses, including heavy metals (HMs), salinity, drought, etc. Various strategies have been employed to palliate the phytotoxic effects of these stressors from the soil–plant system. Nanotechnological approaches have emerged as a promising tool for increasing crop productivity and promoting sustainable agriculture. Interestingly, the seed nano-priming approach has shown potential against all of the above-mentioned abiotic stress factors and has improved crop productivity. The application of nanoparticles (NPs) via seed priming is an innovative and cost-effective approach that improves seed germination and subsequent plant growth by activating plant physiological processes and providing tolerance against various stresses. The seed priming with NPs induces electron exchange and increases surface reaction capabilities related to plant cell and tissue components. This review aims to provide an overview of recent advances and research findings on seed nano-priming and the possible mechanism of plant stress-tolerance augmentation against various stresses. Furthermore, we also shed light on gaps in studies conducted in previous years, which will open new avenues for future research.

In the present study, three different leaf extracts of wild variety of Olea europaea were tested for their phytochemical composition, antioxidant and antimicrobial activities. The antimicrobial activities were determined using the well diffusion method. Phytochemical screening revealed that aqueous, ethanol and ethyl acetate extracts contained alkaloids, flavonoids, steroids, saponins, phenols and tannins while only ethyl acetate fraction was negative for glycosides. Ethanol extract of the plant was observed to have highest contents of alkaloids, flavonoids and phenols. The free radical reducing power assay, DPPH and hydrogen peroxide radical scavenging activities of ethanol extract of O. europaea showed a linear correlation with phenol contents. Ethanol extract was more effective against most of the pathogenic bacteria while aqueous and ethyl acetate extracts were found more potent against most of the fungal strains. The current study revealed that wild variety of O. europaea is as an efficient source of antioxidant and antimicrobial phytochemicals.

PubMedID: 31279144 Non-renewable phosphorus (P) resources are intensively declining and recyclable P is high in demand for agricultural sector. Biochar as a renewable source of P and its physicochemical properties may improve the nutrients condition in the soil for plant availability. This study was designed to evaluate the interaction of biochar with soil microbes in differently textured and P-limited soils for P availability, root colonization and nutrient uptake by plants. Onion plants were grown in two differently textured soils with two types of biochar, with or without P application, three microbially inoculated treatments and uninoculated control. Plants were grown for 65 days and root-shoot biomass, nutrient concentration and mycorrhizal root colonization were analyzed. The WinRhizo was used to evaluate root attributes such as length, surface area and volume of roots. Biochar addition enhanced the nutrient uptake and plant biomass in the presence of P and microbial inoculants. Root colonization was notably increased in biochar + mycorrhizal inoculated plants. Biochar and soil type interactions may develop a unique behavior of nutrient uptake, root colonization, plant growth and root attributes. Biochar in combination with microbial inoculants could be considered a potentially renewable source of P fertilizer. © 2019 Elsevier Ltd 21514107-115.02-188888 This work was supported by TÜBITAK under the program of Research Fellowship Programme for International Researchers [grant number 21514107-115.02-188888 ] and Cukurova University BAP [Project No. FBA_2018_7803 ]. Highly thankful to Prof. Jorge Teodoro De Souza, Department of Plant Pathology, Federal University of Lavras, Brazil for critically reviewing the article. Appendix A

Plant growth-promoting rhizobacteria (PGPR) represent a set of microorganisms that play significant role in improving plant growth and controlling the phytopathogens. Unpredictable performance after the application of PGPR has been observed when these were shifted from in-vitro to in-vivo conditions due to the prevalence of various abiotic stress conditions. During growing period, the potato crop is subjected to a combination of biotic and abiotic stresses. Rhizoctonia solani, a soil-borne plant pathogen, causes reduced vigor and yield of potato crop worldwide. In the current study, multi-stress-tolerant rhizobacterial strain, Bacillus subtilis PM32, was isolated from field-grown potato with various plant growth promoting (PGP) traits including zinc and potassium solubilization, biological nitrogen fixation, ammonia and siderophore, as well as extracellular enzyme productions (cellulase, catalase, amylase, protease, pectinase, and chitinase). The strain PM32 exhibited a distinct potential to support plant growth by demonstrating production of indole-3-acetic acid (102.6 μM/mL), ACC-deaminase activity (1.63 μM of α-ketobutyrate/h/mg protein), and exopolysaccharides (2.27 mg/mL). By retarding mycelial growth of R. solani the strain PM32 drastically reduced pathogenicity of R. solani. The strain PM32 also suppressed the pathogenic activity significantly by impeding mycelial expansion of R. solani with inhibition co-efficient of 49.87. The B. subtilis PM32 also depicted significant tolerance towards salt, heavy metal (Pb), heat and drought stress. PCR based amplification of ituC and acds genes coding for iturin and ACC-deaminase activity respectively indicated potential of strain PM32 for lipopeptides production and ACC deaminase enzyme activity. Results of both in-vitro and pot experiments under greenhouse conditions depicted the efficiency of B. subtilis PM32 as a promising bio-control agent for R. solani infection together with enhanced growth of potato plants as deciphered from biomass accumulation, chlorophyll a, b, and carotenoid contents. Therefore, it was envisioned that application of indigenous multi-stress tolerant PGPR may serve to induce biotic and abiotic stress tolerance in crops/plants for pathogen control and sustainable global food supply. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01067-2.

Rapid industrialization is the main reason of heavy metals contamination of soil colloids and water reservoirs. Heavy metals are persistent inorganic pollutants; deleterious to plants, animals and human beings because of accumulation in food chain. The aim of the current work was to evaluate the role of indole acetic acid (IAA), exopolysaccharide (EPS) and ACC-deaminase producing plant growth promoting rhizobacteria (PGPR) i.e .B. gibsonii PM11 and B. xiamenensis PM14 in metal phytoremediation of metals, their survival and plant growth promotion potential in metal polluted environment as well as alterations in physio-biochemical responses of inoculated L. usitatissimum plants towards heavy metal toxicity. Two bacterial strains Bacillus gibsonii (PM11) and Bacillus xiamenensis (PM14), previously isolated from sugarcane's rhizosphere, were screened for metal tolerance (50 mg/l to 1000 mg/l) and plant growth promoting traits like IAA, ACC-deaminase, EPS production and nitrogen fixing ability under metal stress. The response of flax plant (Linum usitatissimum L.) was analyzed in a pot experiment containing both industrially contaminated and non-contaminated soils. Experiment was comprised of six different treatments, each with three replicates. At the end of the experiment, role of metal tolerant plant growth promoting bacterial inoculation was elucidated by analyzing the plant growth parameters, chlorophyll contents, antioxidative enzymes, and metal uptake both under standard and metal contaminated rhizospheres. Results revealed that root and shoot length, plant's fresh and dry weight, proline content, chlorophyll content, antioxidant enzymatic activity was increased in plants inoculated with plant growth promoting bacteria as compared to non-inoculated ones both in non-contaminated and industrial contaminated soils. In current study, inoculation of IAA, EPS and ACC-deaminase producing bacteria enhances plant growth and nutrient availability by minimizing metal-induced stressed conditions. Moreover, elevated phytoextraction of multi-metals from industrial contaminated soils by PGPR inoculated L. usitatissimum plants reveal that these strains could be used as sweepers in heavy metals polluted environment.

Arbuscular mycorrhizal fungi (AMF) are key attributes for the grassland ecosystems and their occurrence varies with increasing atmospheric nitrogen (N) deposition. The increasing N-deposition inevitably reduces the species richness and changes the community composition in a variety of grassland systems throughout the world. Despite the significant impacts of N-deposition on grassland AMF communities, only limited studies have explicitly examined the N-deposition effects on AMF linked with dominant plant species of grassland. Therefore, the current study investigated the effect of N-addition (e.g., 0, 7.06, 14.14, and 21.19 mg·kg−1) on AMF diversity and community composition linked with two dominant plant species of Inner Mongolia, i.e., Leymus chinensis (L. chinensis), Cleistogene squarrosa (C. squarrosa). The results showed that 65 AMF phylotypes were identified with the most dominant belonging to Glomeraceae (54), and its relative abundance increased with increasing N-addition in both plant species. The increasing N-addition resulted in a significant increase in AMF colonization (maximum 81% at N3), but species richness and diversity were not affected in C. squarrosa. In contrast, L. chinensis showed significantly reduced AMF colonization (minimum 38% at N3) and diversity with increasing N-addition, while species richness was not affected. N-addition did not alter AMF community composition in C. squarrosa, while for L. chinensis, significant differences were recorded. These findings imply that the sensitivity of AMF to N-addition is closely dependent on their host plant species. These findings also provide critical bases for the N-evoked differential response of AMF communities associated with dominant species of temperate grassland system, e.g., L. chinensis and C. squarrosa.

Thirty yellow maize inbred lines were selected from different source populations and planted in isolation with common male testers (YD-2 and YD-4) in 1:4:1 ratio at Cereal Crop Research Institute (CCRI) Pirsabak, Nowshera during spring-2014 (season–I). On the bases of best seed setting and other important traits, eighteen test-crosses were selected using line × tester approach. The developed 18 test-crosses, nine parental lines and two testers along with two check cultivars (Sarhad Yellow and CS2Y10) were grown in summer season-2014 (July – November) using two replications.Data were collected on various maturities and yield related traits via; days to pollen shedding, silking, ear height, plant height, 100-kernel weight, kernel row ear-1 and grain yield. Significant differences were observed among test-crosses for yield related traits mainly 100-kernel weight and grain yield. L-9 using YD-4 as a tester revealed minimum days to pollen shedding (50.5 days) and days to silking (52.5 days). L-3 using YD-2 as a tester recorded maximum plant height while, L-9 using YD-4 as a tester obtained maximum ear height and length. L-9 using YD-4 as a tester revealed high 100-kernel weight, grain yield and high GCA effect, while L-8 using YD-4 as a tester recorded high SCA effect for 100-kernel weight. L-9 exhibited high GCA effect for grain yield while, high SCA effect was obtained for L-2 using tester (YD-2). L-9 using tester YD-4 revealed maximum mid-parent and best-parent heterosis for ear length and grain yield. For maximum traits, L-9 was the best combiner followed by L-3 and L-6 using the same tester (YD-4) under conducted study.

This study describes ZnO NPs biosynthesis using leaf extracts of Verbena officinalis and Verbena tenuisecta. The extracts serve as natural reducing, capping and stabilization facilitators. Plant extracts phytochemical analysis, revealed that V. officinalis showed higher total phenolic and flavonoid content (22.12 and 6.38 mg g (−1) DW) as compared to V. tennuisecta (12.18 and 2.7 mg g (−1) DW). ZnO NPs were characterised by ultraviolet–visible spectroscopy, Fourier transform infrared, X‐ray diffraction, scanning electron microscope, transmission electron microscopy (TEM) and energy dispersive X‐ray. TEM analysis of ZnO NPs reveals rod and flower shapes and were in the range of 65–75 and 14–31 nm, for V. tenuisecta and V. officinalis, respectively. Bio‐potential of ZnO NPs was examined through their leishmanicidal potential against Leishmania tropica. ZnO NPs showed potent leishmanicidal activity with 250 µg ml(−1) being the most potent concentration. V. officinalis mediated ZnO NPs showed more potent leishmanicidal activity compared to V. tenuisecta mediated ZnO NPs due to their smaller size and increased phenolics doped onto its surface. These results can be a step forward towards the development of novel compounds that can efficiently replace the current medication schemes for leishmaniasis treatment.

Development of superior genotypes is the main aim all breeding programs. For this purpose comprising 14 spring wheat advanced lines with four checks were evaluated for six yield parameters during 2011-12 in an RCB design with three replications. Analysis of variance revealed highly significant differences (P?0.01) for all the studied traits except harvest index which showed significant differences (P?0.05). Mean values ranged between 87.7 to 110.4 cm for plant height, 29.1 to 38.1 cm for peduncle length, 1.91 to 2.89 g for grain weight spike-1, 5617.3 to 7197.5 kg for grain yield ha-1, 15679 to 20123 kg for biological yield ha-1 and 34.94 to 42.40% for harvest index. Grain yield has significant correlation with grain weight spike-1 (0.407**), biological yield (0.486**) and harvest index (0.549**). High heritability was observed for grain weight spike-1 (71.74%), grain yield ha-1 (69.01%) and biological yield ha-1 (71.87%).

Herein, we describe the green synthesis of silver nanoparticles (AgNPs) using Ocimum basilicum L. var. thyrsiflora leaf derived callus extracts formed in response to 9.0 μM of thidiazuron (TDZ) alone and a combination of 9.0 μM of TDZ + 15 μM of melatonin (Mel) which act both as reducing and stabilizing agents. Based on the phytochemical analysis, the highest total phenolic and flavonoid content were recorded (44.9 mg g−1 DW and 31.5 mg g−1 DW, respectively) in the callus grown on TDZ (9.0 μM) + Mel (15 μM) compared to the TDZ alone (29.8 mg g−1 DW and 17.6 mg g−1 DW, respectively) induced callus. The biosynthesized AgNPs were confirmed by analyzing the excitation of surface plasmon resonance using ultraviolet-visible spectroscopy at 420–430 nm. The synthesized AgNPs were characterized via X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, which indicate that more potent antibacterial and antileishmanial activity is displayed by the Mel plus TDZ callus extract mediated AgNPs than the TDZ-only callus extract mediated AgNPs against multiple drug resistant human pathogens and Leishmania major. Determination of the antileishmanial efficacy of AgNPs is a major step towards the development of new compounds containing nanoparticles for leishmaniasis treatment.

Bacillus pumilus strain SCAL1 is an endophytic, thermophilic plant that was isolated from the leaf of a plant, Solanum lycopersicum L., in Sindh, Pakistan. B. pumilus strain SCAL1 has usually exhibited high resistance to environmental stresses, with a growth temperature ranging from 30 to 60°C. An approximately 3.75-Mb draft genome was assembled into 68 contigs.

A field experiment was conducted at Agriculture Research Station Bahawalpur (Pakistan) during Kharif, 2016 to evaluate the response of cluster bean against bio and chemical fertilizers. The treatments consisted of three levels of nitrogen (urea 75g, 85g and 95g/40g seeds) with three level of Rhizobium (1.5g, 2.0g and 2.5g/40g of seeds). The experiment arranged in a randomized complete block design with 16 treatments and three replications. Combine treatment of urea and Rhizobium resulted in maximum plant height, number of pods/plants, number of seeds/pod, 1000 seeds weight, yield/plant, and chlorophyll content. Similarly, application of 2.5g rhizobium and 85g of urea separately resulted in highest number of leaves. Our results concluded that the use of urea and rhizobium in consortium could be a potential agronomic practice for the production of high grain yield in cluster bean.

Plant growth-promoting endophytes (PGPEs) can colonize the internal tissues of plants and are capable of promoting plant growth. These bacteria can improve plant tolerance against various biotic and abiotic stresses via the expression of antioxidant enzymes and the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Two salt-tolerant PGPEs, Kocuria rhizophila: KF875448 (14ASP) and Cronobacter sakazakii: KM042090 (OF115), with ACC deaminase activity were investigated for their potential to ameliorate plant salinity stress. The wheat varieties Pasban 90 and Khirman were subjected to two levels of salt stress (80 and 160 mM NaCl) under greenhouse conditions by using a completely randomized design. Analyses of plant growth parameters, antioxidant enzyme activities, chlorophyll and plant mineral contents were conducted to investigate the stress tolerance induced by the PGPEs. The ACC utilization by the PGPEs directly relates to the promotion of plant growth due to the lowering of excess ethylene production under salt stress. High levels of NaCl exhibited negative effects in both varieties. However, inoculation with PGPEs increased the morphological traits and antioxidant activities of the plants while decreasing the Na+ contents in all treatments compared to uninoculated treatment. Wheat variety Pasban 90 was more tolerant than Khirman in to salt stress in all the measured morphological and biochemical parameters, while the bacterial strain OF115 performed significantly better in all morphological and biochemical parameters, such as fresh dry weight, root shoot length, proline and chlorophyll contents, compared to strain 14ASP. The K+/Na+ ratio in the tissues of bacterial treated plants was higher than the control, probably in order to maintain the nutrient balance. The results of our study revealed that the inoculation of plants by ACC deaminase-producing PGPEs is a potential tool for the enhancement of plant growth and stress tolerance. Moreover, endophytic bacteria allied with host plants are capable of enduring high saline conditions and can interact with plants in a very efficient way.

Bacillus pumilus strain SCAL1 is an endophytic, thermophilic plant that was isolated from the leaf of a plant, Solanum lycopersicum L., in Sindh, Pakistan. B. pumilus strain SCAL1 has usually exhibited high resistance to environmental stresses, with a growth temperature ranging from 30 to 60°C. An approximately 3.75-Mb draft genome was assembled into 68 contigs. This research was supported by Department of Biological Sciences, Thompson Rivers University, Canada. We thank Jonathan D. Van Hamme, Department of Biological Sciences, Thompson Rivers University, for sequencing B. pumilus SCAL1 and assisting with data analysis. We thank Rachel Backer, Department of Plant Science, McGill University, for assistance with English language revisions.

Objective To investigate the proximate composition, minerals analysis, phytochemical screening, gas chromatography-mass spectrometry (GC-MS) studies of active cannabinoids and antimicrobial activities of Cannabis indica ( C. indica ) leaves, stems, and seeds. Methods Standard qualitative protocols of phytochemical screening were accomplished for the identification of biologically active phytochemicals. Minerals in plant samples were analyzed by using atomic absorption spectrophotometer. The resins of C. indica were analyzed for medicinally active cannabinoid compounds by GC-MS. The sample for GC-MS study was mixed with small quantity of n -hexane and 30 mL of acetonitrile solution for the identification of cannabinoids. Agar well diffusion method was used for antibacterial activity. For antifungal activity, the tested fungal strains were sub-cultured on Sabouraud's dextrose agar at 28 °C. Results Mineral analysis revealed the presence of sodium, potassium, magnesium and some other minerals in all parts of C. indica . Phytochemical investigation showed the presence of alkaloids, saponins, tannins, flavonoids, sterols and terpenoids. C. indica divulged wide spectrum of antibacterial activities against Staphylococcus aureus, Bacillus cereus, Klebsiella pneumoniae , and Proteus mirabilis . The extracts of plant leaves, seeds and stems showed significant antifungal activities against Aspergillus niger, Aspergillus parasiticus , and Aspergillus oryzae . The biologically active cannabinoids of delta-9-tetrahydrocannabinol (25.040%) and cannabidiol (resorcinol, 2-p-mentha-1,8-dien-4-yl-5-pentyl) (50.077%) were found in Cannabis resin in high percentage. Conclusions The findings of the study suggested that the existence of biologically active remedial cannabinoids in elevated concentrations and antimicrobial bioassays of C. indica make it a treasured source to be used in herbal preparation for various ailments.

Olive plant produces a variety of bioactive molecules and thus has important medicinal value in folk medicine. In this study, different leaf and fruit extracts of Pakistani wild variety of Olea europaea was tested for their phytochemical content, antimicrobial activity and mass spectrometric analysis. Olive leaves and fruit samples were extracted with five different solvents to obtain the crude extract and screened for various kinds of phytochemicals. Phytochemicals were further confirmed through Fourier Transmission Infra-red Spectroscopy (FTIR).The plant extract showed significant antimicrobial activity against all the strains tested. Methanol, ethanol and ethyl acetate extracts were found more effective against most of the pathogenic bacteria with high zone of inhibition. Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed that olive fruits have Oleic acid, Palmitic acid, Linoleic acid, Octadecadienoic acid, Stearic acid, Palmitoleic acid and Tridecanoic acid as oil contents. In this work, the antimicrobial potential and phytochemical contents were explored which may further pave the way for the bio-industrial applications. Keywords: Olea europaea; Phytochemical content; Antimicrobial activity; GC-MS analysis http://dx.doi.org/10.19045/bspab.2017.60032

In this study, a novel approach for in vitro regeneration of Piper nigrum L. has been applied in order to increase healthy biomass, phytochemicals and piperine production via reverse photoperiod (16hD/8hL). Leaf portions of the seed-derived plants were placed on an MS-medium fortified with different PGRs. Under 16hD/8hL, thidiazuron (TDZ; 4.0 mg L⁻¹) and BA (1.5 mg L⁻¹) was found to be the most effective (90%) in callus induction. Two concentrations (1.5, 2.0 mg L⁻¹) of the IBA produced80% shoots from callus cultures. Healthy shoots were transferred to rooting medium and higher percentage of rooting (90%) was observed on IBA (1.5 mg L⁻¹). These in vitro tissues were subjected to amino acid analysis, spectrophotometry, and HPLC. ARG, SER, THR, and TYR were the most abundant components out of 17 amino acids. Higher amino acid production was observed under normal photoperiod (16hL/8hD) than under reverse photoperiod (16hD/8hL). The highest total phenolic content (TPC; 9.91 mg/g-DW) and flavonoid content (7.38 mg/g-DW) were observed in callus cultures incubated under 16hL/8hD than other tissues incubated under 16hD/8hL photoperiod. Higher DPPH and PoMo activities were observed in tissues incubated under 16hL/8hD photoperiod, while ABTS and Fe²⁺ chelating activities were found higher in tissues incubated under reverse photoperiod. Significant quantities of piperine content were observed in all tissues except callus cultures. These results suggest that reverse photoperiod is a promising approach for callus induction, phytochemicals and piperine production for commercial applications.

Heliotropium bacciferumis paramount in medicinal perspective and belongs to Boraginaceae family. The crude and numerous fractions of leaves, stem, and roots of the plant were investigated for phytochemical analysis and DPPH radical scavenging activity. Phytochemical analysis of crude and fractions of the plant revealed the presence of alkaloids, saponins, tannins, steroids, terpenoids, flavonoids, glycosides, and phenols. The antioxidant (free radical scavenging) activity of various extracts of theHeliotropium bacciferumwas resolute against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with the avail of UV spectrophotometer at 517 nm. The stock solution (1000 mg/mL) and then several dilutions (50, 100, 150, 200, and 250 mg/mL) of the crude and fractions were prepared. Ascorbic acid was used as a standard. The plant leaves (52.59 ± 0.84 to 90.74 ± 1.00), stem (50.19 ± 0.92 to 89.42 ± 1.10), and roots extracts (49.19 ± 0.52 to 90.01 ± 1.02) divulged magnificent antioxidant activities. For the ascertainment of the fatty acid constituents a gas chromatograph hyphenated to mass spectrometer was used. The essential fatty acids for growth maintenance such as linoleic acid (65.70%), eicosadienoic acid (15.12%), oleic acid (8.72%), and palmitic acid (8.14%) were found in high percentage. The infrared spectra of all extracts of the plant were recorded by IR Prestige-21 FTIR model.

The present study was designed to investigate the mineral content and antimicrobial activity of Curcuma Longa extracts and its essential oil. We also determined the lipid peroxidation inhibition activity of the ethanolic extract against sodium nitroprusside (SNP) induced thiobarbituric acid reactive species (TBARS) formation in rat's brain, kidney and liver homogenates. Major constituents of essential oil identified by gas chromatography and mass spectrometry (GCMS) were beta-sesquiphellandrene (38.69%), alpha-curcumene (18.44%) and p-mentha-1,4 (8)-diene (16.29%). Atomic absorption spectroscopy (AAS) was used for the quantitative estimation of Calcium (Ca), Magnesium (Mg), Iron (Fe), Copper (Cu), Zinc (Zn), Chromium (Cr), Nickel (Ni) and Manganese (Mn). The extract showed highest Mg (49.4 mg/l) concentration followed by Ca (35.42 mg/l) and Fe (1.27 mg/l). Our data revealed that the ethanolic extract of Curcuma Longa at 1-10 mg/kg significantly inhibited TBARS production in all tested homogenates. Crude extracts and essential oil were tested against three gram positive bacteria i.e. Bacillus subtilis, Bacillus atrophoeus, Staphylococcus aureus, six gram negative bacteria i.e. Escherichia coli, Klebsiella pneumonias, Salmonella typhi, Pseudomonas aeruginosa, Erwinia carotovora, Agrobacterium tumefaciens and one fungal strain namely Candida albicans by disc diffusion assay. Essential oil showed highest anti-microbial activity as compared to the crude extracts. The present study confirms the significant antimicrobial and antioxidant potential of the studied plant, which can be considered as a diet supplement for a variety of oxidative stress induced or infectious diseases.