Insights into diversity and L-asparaginase activity of fungal endophytes associated with medicinal plant Grewia hirsuta.

L-asparaginase is used as one of the prime chemotherapeutic agents to treat acute lymphoblastic leukemia. The present work aimed to study the endophytic fungal diversity of Grewia hirsuta and their ability to produce L-asparaginase. A total of 1575 culturable fungal endophytes belonging to four classes, Agaricomycetes, Dothideomycetes, Eurotiomycetes, and Sordariomycetes, were isolated. The isolates were grouped into twenty-one morphotypes based on their morphological characteristics. Representative species from each group were identified based on their microscopic characteristics and evaluation of the ITS and LSU rDNA sequences. Most of the fungal endophytes were recovered from the leaves compared to other plant parts. Diaporthe sp. was the predominant genus with a colonization frequency of 8.62%. Shannon-Wiener index for diversity ranged from 2.74 to 2.88. All the plant parts showed similar Simpson's index values, indicating a uniform species diversity. Among the sixty-three fungal endophytes screened, thirty-two were identified as L-asparaginase-producing isolates. The enzyme activities of fungal endophytes estimated by the nesslerization method were found to be in the range of 4.65-0.27 IU/mL with Fusarium foetens showing maximum enzyme activity of 4.65 IU/mL. This study for the first time advocates the production of L-asparaginase from Fusarium foetens along with the endophytic fungal community composition of Grewia hirsuta. The results indicate that the fungal endophyte Fusarium foetens isolated in the present study could be a potent source of L-asparaginase.

Response surface methodology based optimized production, purification, and characterization of L-asparaginase from Fusarium foetens.

L-asparaginase is used as one of the prime chemotherapeutic agents to treat acute lymphoblastic leukemia. L-asparaginase obtained from bacteria exhibits hypersensitive reactions including various side effects. The present work aimed to optimize growth parameters for maximum production of L-asparaginase by Fusarium foetens through response surface methodology, its purification, and characterization. The optimization of L-asparaginase production by Fusarium foetens was initially done through a one-factor-at-a-time method. L-asparaginase production was further optimized using a central composite design based response surface methodology. The maximum L-asparaginase activity of 12.83 IU/ml was obtained under the following growth conditions; temperature-27.5 °C, pH-8, inoculum concentration-1.5 × 106 spores/ml, and incubation period-7 days. In comparison with the unoptimized growth conditions (4.58 IU/ml), the optimization led to a 2.65-fold increase in the L-asparaginase activity. The L-asparaginase from Fusarium foetens was purified 15.60-fold, with a yield of 39.89% using DEAE-cellulose column chromatography. After purification, the L-asparaginase activity was determined to be 127.26 IU/ml and the specific activity was found to be 231.38 IU/mg. The molecular mass was estimated to be approximately 37 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme showed optimum activity at pH 5, and a temperature of 40 °C. The enzyme showed 100% specificity towards L-asparagine and no activity towards L-glutamine. Its activity was enhanced by Mn2+, Fe2+, and Mg2, while it was inhibited by ß-mercaptoethanol and EDTA. The Km and Vmax of the purified L-asparaginase were found to be 23.82 mM and 210.3 IU/ml respectively. The results suggest that Fusarium foetens could be a potent candidate for the bioprocessing of L-asparaginase at a large scale.

Endophytic Fungi as a Promising Source of Anticancer L-Asparaginase: A Review.

L-asparaginase is a tetrameric enzyme from the amidohydrolases family, that catalyzes the breakdown of L-asparagine into L-aspartic acid and ammonia. Since its discovery as an anticancer drug, it is used as one of the prime chemotherapeutic agents to treat acute lymphoblastic leukemia. Apart from its use in the biopharmaceutical industry, it is also used to reduce the formation of a carcinogenic substance called acrylamide in fried, baked, and roasted foods. L-asparaginase is derived from many organisms including plants, bacteria, fungi, and actinomycetes. Currently, L-asparaginase preparations from Escherichia coli and Erwinia chrysanthemi are used in the clinical treatment of acute lymphoblastic leukemia. However, they are associated with low yield and immunogenicity problems. At this juncture, endophytic fungi from medicinal plants have gained much attention as they have several advantages over the available bacterial preparations. Many medicinal plants have been screened for L-asparaginase producing endophytic fungi and several studies have reported potent L-asparaginase producing strains. This review provides insights into fungal endophytes from medicinal plants and their significance as probable alternatives for bacterial L-asparaginase.

Epigenetic Modifiers Revamp Secondary Metabolite Production in Endophytic Nigrospora sphaerica.

During plant interaction, endophytes provide benefits to the host plant. Endophytes also contribute a variety of structural attributes with biological potential. Nigrospora sphaerica, which produces phomalactone from Adiantum philippense L., was subjected to epigenetic modification. High-performance liquid chromatography (HPLC) and Gas chromatography-mass spectrometry (GCMS) analysis were used to determine secondary metabolite profiling. Epigenetic modifiers like DNA Methyltransferase (DNMT) and Histone deacetylase (HDAC) inhibitors increased the expression of biosynthetic pathways. The activation of new metabolites was observed as a result of the activation of cryptic biosynthetic gene clusters, as well as the silencing of phomalactone in some treatments. When compared to DNMT treatments, HDAC treatments showed a significant increase in cryptic metabolite induction. The induction of cryptic metabolites with biological significance by HDAC treatment is supported by our findings.

Morphological and molecular characterization of Neopestalotiopsis vitis associated with leaf blight disease of Manilkara zapota-a new record from India.

Sapota is an important horticultural crop grown in India, and Karnataka is a major producer of sapota. A characteristic leaf blight disease was observed in Southern Karnataka during field surveys conducted in 2019 with an incidence of 13-22% in approximately 45 ha of sapota field. The leaf blight-associated pathogen was isolated on the potato dextrose agar medium. A total of 12 isolates obtained from each location were identified culturally and morphologically. Based on the morphological and cultural features, the pathogen was identified as Pestalotiopsis or Neopestalotiopsis, which was further confirmed by molecular identification using a representative isolate (MZ03). The ITS rDNA and ß-tubulin genes were amplified and sequenced using ITS1/ITS4 and T1/T22 primer pairs respectively. nBLAST search analysis and concatenated (ITS-rDNA and TUB2 loci) phylogenetic analysis confirmed the pathogen identity as Neopestalotiopsis vitis. Pathogenicity tests conducted on detached leaves by inoculation with a conidial suspension of N. vitis produced typical blight symptoms after 4-5 days and progressed to cover the entire leaf lamina after 10-12 days. The pathogen's identity was confirmed after re-isolation by cultural and morphological features. Although Pestalotiopsis clavispora and Pestalotiopsis versicolor causing diseases on sapota seedlings and trees have been reported, no reports are available for the occurrence of N. vitis to sapota from India. This is the first report of N. vitis associated with leaf blight disease of sapota from India.

Antimicrobial metabolite profiling of Nigrospora sphaerica from Adiantum philippense L.

BACKGROUND: Endophyte bestows beneficial aspects to its inhabiting host, along with a contribution to diverse structural attributes with biological potential. In this regard, antimicrobial profiling of fungal endophytes from medicinal plant Adiantum philippense revealed bioactive Nigrospora sphaerica from the leaf segment. Chemical and biological profiling through TLC-bioautography and hyphenated spectroscopic techniques confirmed the presence of phomalactone as an antimicrobial metabolite. RESULTS: The chemical investigation of the broth extract by bioassay-guided fractionation confirmed phomalactone as a bioactive antimicrobial secondary metabolite. The antimicrobial activity of phomalactone was found to be highest against Escherichia coli by disc diffusion assay. The MIC was found to be significant against both Escherichia coli and Xanthomonas campestris in the case of bacteria and dermatophyte Candida albicans at 150 µg/ml, respectively. CONCLUSIONS: Overall, the results highlighted the antimicrobial potential of phomalactone from the endophyte Nigrospora sphaerica exhibiting a broad spectrum of antimicrobial activity against human and phytopathogenic bacteria and fungi. This work is the first report regarding the antibacterial activity of phomalactone.

Application of Optimized and Validated Agar Overlay TLC-Bioautography Assay for Detecting the Antimicrobial Metabolites of Pharmaceutical Interest.

The agar overlay TLC-bioautography is one of the crucial methods for simultaneous in situ detection and separation of antimicrobial metabolites of pharmaceutical interest. The main focus of this research relies on the dereplication of an antimicrobial metabolite coriloxin derived from mycoendophytic Xylaria sp. NBRTSB-20 with a validation of agar overlay TLC-bioautography technique. This polyketide metabolite coriloxin was purified by column chromatography, and its purity was assessed by HPLC, UPLC-ESI-QTOF-MS, FT-IR and NMR spectral analysis. The antimicrobial capability of ethyl acetate extract and the purified compound coriloxin was determined by disc diffusion, minimal inhibitory concentration and agar overlay TLC-bioautography assay. The visible LOD of coriloxin antimicrobial activity was found at 10 µg for Escherichia coli and 20 µg for both Staphylococcus aureus and Fusarium oxysporum. Inter- and intra-day precision was determined as the relative standard deviation is less than 6.56%, which proved that this method was precise. The accuracy was expressed as recovery, and the values were found ranging from 91.18 to 108.73% with RSD values 0.94-2.30%, respectively. The overall findings of this investigation suggest that agar overlay TLC-bioautography assay is a suitable and acceptable method for the in situ determination of antimicrobial pharmaceuticals.

Endo-symbiont mediated synthesis of gold nanobactericides and their activity against human pathogenic bacteria.

Synthesis of gold nanobactericides (AuNBs) were achieved by treating 1mM chloroaurate with cell free supernatant of Aneurinibacillus migulanus. Formation of AuNBs was initially was monitored with change in colour to ruby red. Further confirmation was assessed with UV-visible spectra with maximum absorption occurring at 510nm. Transmission electron microscopy (TEM) analysis revealed the polydispersity of AuNBs with size distribution ranging from 10 to 60nm with an average size of 30nm. Crystalline nature was studied using X-ray diffraction which exhibited characteristic peaks indexed to Bragg's reflection at 2θ angle which confers (111), (200), (220), and (311) planes suggesting AuNBs were face-centred cubic. Fourier transform infrared spectroscopy (FTIR) analysis revealed absorption peaks occurring at 3341cm-1, 1635cm-1 and 670cm-1 which corresponds to functional groups attributing to synthesis. The antibacterial efficacy of AuNBs was tested against selective human pathogenic bacteria and activity was measured as zone of inhibition by using disc and well diffusion. Bactericidal activity was interpreted with standard antibiotics gentamicin and kanamycin. Micro broth dilution assay expressed the minimal concentration of AuNBs to inhibit the growth of test pathogens. Highest activity was observed against Pseudomonas aeruginosa (MTCC 7903) with 21.00±0.57mm compared to other pathogens. The possible mode of action of AuNBs on DNA was carried out with in vitro assay as preliminary test against pathogenic DNA isolated from P. aeruginosa. Further studies will be interesting enough to reveal the exact interactive mechanism of AuNBs with DNA. Overall study contributes towards biogenic synthesis of AuNBs as one of the alternative in combating drug resistant pathogens.

Chemogenomics driven discovery of endogenous polyketide anti-infective compounds from endosymbiotic Emericella variecolor CLB38 and their RNA secondary structure analysis.

In the postgenomic era, a new strategy for chemical dereplication of polyketide anti-infective drugs requires novel genomics and chromatographic strategies. An endosymbiotic fungal strain CLB38 was isolated from the root tissue of Combretum latifolium Blume (Combretaceae) which was collected from the Western Ghats of India. The isolate CLB38 was then identified as Emericella variecolor by its characteristic stellate ascospores culture morphology and molecular analysis of ITS nuclear rDNA and intervening 5.8S rRNA gene sequence. ITS2 RNA secondary structure modeling clearly distinguished fungal endosymbiont E. variecolor CLB38 with other lifestyles in the same monophyletic clade. Ethyl acetate fraction of CLB38 explored a broad spectrum of antimicrobial activity against multidrug resistant pathogens. Biosynthetic PKS type-I gene and chromatographic approach afford two polyketide antimicrobial compounds which identified as evariquinone and isoindolones derivative emerimidine A. MIC of purified compounds against test microorganisms ranged between 3.12 µg/ml and 12.5 µg/ml. This research highlights the utility of E. variecolor CLB38 as an anticipate source for anti-infective polyketide metabolites evariquinone and emerimidine A to combat multidrug resistant microorganisms. Here we demonstrates a chemogenomics strategy via the feasibility of PKS type-I gene and chromatographic approach as a proficient method for the rapid prediction and discovery of new polyketides compounds from fungal endosymbionts.

Biogenic nanoparticles bearing antibacterial activity and their synergistic effect with broad spectrum antibiotics: Emerging strategy to combat drug resistant pathogens.

The present study emphasizes on synthesis of bimetallic silver-gold nanoparticles from cell free supernatant of Pseudomonas veronii strain AS41G inhabiting Annona squamosa L. The synthesized nanoparticles were characterized using hyphenated techniques with UV-Visible spectra ascertained absorbance peak between 400 and 800 nm. Possible interaction of biomolecules in mediating and stabilization of nanoparticles was depicted with Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) displayed Bragg's peak conferring the 1 0 0, 1 1 1, 2 0 0, and 2 2 0 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Size and shape of the nanoparticles were determined using Transmission electron microscopy (TEM) microgram with size ranging from 5 to 50 nm forming myriad shapes. Antibacterial activity of nanoparticles against significant human pathogens was conferred with well diffusion assay and its synergistic effect with standard antibiotics revealed 87.5% fold increased activity with antibiotic "bacitracin" against bacitracin resistant strains Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae followed by kanamycin with 18.5%, gentamicin with 11.15%, streptomycin with 10%, erythromycin with 9.7% and chloramphenicol with 9.4%. Thus the study concludes with biogenic and ecofriendly route for synthesizing nanoparticles with antibacterial activity against drug resistant pathogens and attributes growing interest on endophytes as an emerging source for synthesis of nanoparticles.

Corrigendum to "Mycosynthesis of silver nanoparticles bearing antibacterial activity" [Saudi Pharm. J. 24 (2016) 140-146].

[This corrects the article DOI: 10.1016/j.jsps.2015.01.008.].

Intra-specific differentiation of fungal endosymbiont Alternaria longissima CLB44 using RNA secondary structure analysis and their anti-infective potential.

New antimicrobial agents derived from endosymbio-tic fungi with unique and targeted mode of action are crucially rudimentary to combat multidrug-resistant infections. Most of the fungi isolated as endosymbionts show close morphological feature resemblance to plant pathogenic or free-living forms, and it is difficult to differentiate these different lifestyles. A fungal endosymbiont strain CLB44 was isolated from Combretum latifolium Blume (Combretaceae). CLB44 was then identified as Alternaria longissima based on morphological and internal transcribed spacer (ITS) intervening 5.8S rRNA gene sequence analysis. ITS2 RNA secondary structure analysis was carried out using mfold server with temperature 37 °C, and anti-infective potential was determined by MIC and disk diffusion methods. ITS2 RNA secondary structure analysis clearly distinguished endosymbiotic A. longissima CLB44 from free-living and pathogenic A. longissima members in the same monophyletic clade. Secondary metabolites produced effectively inhibited Pseudomonas aeruginosa (25 µg/ml), Escherichia coli (25 µg/ml), methicillin-resistant Staphylococcus aureus (50 µg/ml), Candida albicans (100 µg/ml), and other human pathogens. This study emerges as an innovative finding that explores newly revealed ITS2 RNAs that may be an insight as new markers for refining phylogenetic relations and to distinguish fungal endosymbionts with other free-living or pathogenic forms. A. longissima CLB44, in the emerging field of endosymbionts, will pave the way to a novel avenue in drug discovery to combat multidrug-resistant infections. The sequence data of this fungus is deposited in GenBank under the accession no. KU310611.

Biomimetic Synthesis of Silver Nanoparticles Using Endosymbiotic Bacterium Inhabiting Euphorbia hirta L. and Their Bactericidal Potential.

The present investigation aims to evaluate biomimetic synthesis of silver nanoparticles using endophytic bacterium EH 419 inhabiting Euphorbia hirta L. The synthesized nanoparticles were initially confirmed with change in color from the reaction mixture to brown indicating the synthesis of nanoparticles. Further confirmation was achieved with the characteristic absorption peak at 440 nm using UV-Visible spectroscopy. The synthesized silver nanoparticles were subjected to biophysical characterization using hyphenated techniques. The possible role of biomolecules in mediating the synthesis was depicted with FTIR analysis. Further crystalline nature of synthesized nanoparticles was confirmed using X-ray diffraction (XRD) with prominent diffraction peaks at 2θ which can be indexed to the (111), (200), (220), and (311) reflections of face centered cubic structure (fcc) of metallic silver. Transmission electron microscopy (TEM) revealed morphological characteristics of synthesized silver nanoparticles to be polydisperse in nature with size ranging from 10 to 60 nm and different morphological characteristics such as spherical, oval, hexagonal, and cubic shapes. Further silver nanoparticles exhibited bactericidal activity against panel of significant pathogenic bacteria among which Pseudomonas aeruginosa was most sensitive compared to other pathogens. To the best of our knowledge, present study forms first report of bacterial endophyte inhabiting Euphorbia hirta L. in mediating synthesizing silver nanoparticles.

Implication of PKS type I gene and chromatographic strategy for the biodiscovery of antimicrobial polyketide metabolites from endosymbiotic Nocardiopsis prasina CLA68.

Advanced approach in probing for polyketide antimicrobials requires novel genomics and chromatographic strategies. An endophytic strain CLA68 was isolated from the root of Combretum latifolium Blume (Combretaceae) collected from the Western Ghats of Southern India. Strain CLA68 was then identified as Nocardiopsis prasina by its characteristic culture morphology and analysis of 16S rRNA gene sequence. Biosynthetic polyketide synthase genes were investigated using two pairs of degenerate primers. Ethyl acetate extract of CLA68 exhibited broad spectrum activity against a panel of test human pathogens. PKS type-I gene detection and chromatographic strategy yielded a robust polyketide antimicrobial compound which identified as nocapyrone E. Minimum inhibitory concentration of the purified compound against MRSA and other human pathogens ranged between 25 and 100 µg/ml. The present work highlights the utility of N. prasina CLA68 as potential source for antimicrobial polyketide nocapyrone E which could help to combat multidrug-resistant pathogens. This study demonstrates feasibility of PKS type-I gene-based molecular approach and chemical investigation by chromatographic approach is the best method for prediction and rapid discovery of novel polyketides from endosymbiotic actinomycetes. The sequence data of this endosymbiotic actinomycete is deposited in GenBank under the accession no. KP269077.

Mycosynthesis of silver nanoparticles bearing antibacterial activity.

Mycosynthesis of silver nanoparticles was achieved by endophytic Colletotrichum sp. ALF2-6 inhabiting Andrographis paniculata. Well dispersed nanoparticles were characterized using UV-Visible spectrometry with maximum absorption conferring at 420 nm. FTIR analysis revealed possible biomolecules reducing the metal salt and stabilization of nanoparticles. XRD analysis depicted the diffraction intensities exhibiting between 20 and 80 °C at 2theta angle thus conferring the crystalline nature of nanoparticles. Morphological characteristic using TEM revealed the polydispersity of nanoparticles with size ranging from 20 to 50 nm. Synthesized nanoparticles exhibited bactericidal activity against selected human pathogens. Nanoparticles mode of action was carried out to reveal DNA damage activity. Thus the present investigation reports facile fabrication of silver nanoparticles from endophytic fungi.

Endogenic mediated synthesis of gold nanoparticles bearing bactericidal activity.

The present investigation aimed to synthesize gold nanoparticles using Pseudomonas fluorescens 417 inhabiting Coffea arabica L. Biologically synthesized gold nanoparticles were polydispersed in nature and characterized using hyphenated techniques such as UV-visible spectrophotometry, which ascertained characteristic peaks between 450 nm and 650 nm. Fourier transform infrared analysis predicted the functional groups present in the cell-free supernatant that mediated the synthesis and stabilization of gold nanoparticles. The crystalline nature of the gold nanoparticles was analyzed with X-ray diffraction techniques that displayed the Bragg's diffraction intensity. Transmission electron microscopy revealed the size of nanoparticles ranging from 5 nm to 50 nm, with most of them bearing a spherical shape. The study also revealed the bactericidal activity of synthesized nanoparticles against a panel of clinically significant pathogens. Maximum activity was observed against Pseudomonas aeroginosa followed by Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae. The results obtained in the present investigation are promising for ecofriendly approaches for synthesis of gold nanoparticles bearing bactericidal activity that can act as an alternative to combat drug-resistant pathogens.

Biosynthesis of gold nanoparticles by Pseudomonas veronii AS41G inhabiting Annona squamosa L.

Biogenic principles to nanotechnology have generated tremendous attention in recent past owing eco friendly benign process for synthesis of nanoparticles. Present investigation reports extracellular synthesis of gold nanoparticles using cell free supernatant of Pseudomonas veronii AS 41G, a novel endophyte isolated from Annona squamosa L. Gold nanoparticles formation was confirmed with UV-Visible spectrophotometer. FTIR analysis predicted various functional groups responsible for reduction of metal salts and stabilization of gold nanoparticles. Nanoparticles were crystalline in nature as shown in XRD pattern. TEM analysis revealed morphological characteristics of nanoparticles with different size. Thus the present study attributes for facile process for synthesis of gold nanoparticles as an alternative for conventional methods. The study also highlights the new role of novel bacterium Pseudomonas veronii AS41G which will be very valuable as a record for the researchers working on it.

Molecular characterization of an endophytic Phomopsisliquidambaris CBR-15 from Cryptolepis buchanani Roem. and impact of culture media on biosynthesis of antimicrobial metabolites.

An endophytic fungus Phomopsis liquidambaris CBR-15, was isolated from Cryptolepis buchanani Roem. (Asclepiadaceae) and identified by its characteristic culture morphology and molecular analysis of the ITS region of rDNA and intervening 5.8S rRNA gene. The impact of different culture media on biosynthesis of antimicrobial metabolites was tested by disc diffusion assay. Polyketide synthase gene (PKS) of the endophytic fungus was investigated using three pairs of degenerate primers LC1-LC2c, LC3-LC5c and KS3-KS4c by PCR. TLC-bioautography method was employed to detect the antimicrobial metabolites. Antimicrobial metabolites fractionated with ethyl acetate extract showed significant antimicrobial activity against the test bacteria and fungi. Biosynthesis of antimicrobial metabolites was optimum as depicted by zone of inhibition from ethyl acetate extract cultured in potato dextrose broth. Strain CBR-15 was identified as Phomopsisliquidambaris and PKS genes of the fungus were amplified with LC3-LC5c and KS3-KS4c sets of degenerate primers. These findings suggest that endophytic P.liquidambaris CBR-15 harbor iterative type I fungal PKS gene domain which indicates the biosynthetic potential of endophytic fungi as producers of natural antimicrobial metabolites. The study also demonstrates the utilization and optimization of different culture media which best supports for the biosynthesis of the antimicrobial metabolites from P.liquidambaris.

Molecular profiling and antimicrobial potential of endophytic Gliomastix polychroma CLB32 inhabiting Combretum latifolium Blume.

Fungal endophytes as a source of bioactive metabolites have led to the development of pharmaceutical products finding new applications. In a survey of endophytic fungal biodiversity, an antimicrobial endophytic strain CLB32 was isolated from the leaf of Combretum latifolium Blume (Combretaceae) from the Western Ghats of Southern India. CLB32 was then identified as Gliomastix polychroma (KR704576) by morphological and phylogenetic analysis based on internal transcribed spacer (ITS) nuclear rDNA and intervening 5.8S rRNA gene. CLB32 here constituted the first report on incidence of endophytic fungi from C. latifolium Blume. Ethyl acetate fraction of strain CLB32 was evaluated for antimicrobial activity by disc diffusion assay. Secondary metabolites produced effectively inhibited methicillin-resistant Staphylococcus aureus (18.33 ± 0.33 mm), Pseudomonas aeruginosa (14.66 ± 0.33 mm) and Candida albicans (14.00 ± 0.57 mm). Biosynthesis of these antimicrobial compounds was detected by analytical TLC-bioautography method as depicted by zone of inhibition on intensive the band. These findings suggest that G. polychroma CLB32, as a producer of natural antimicrobial drugs, could help to combat against multidrug-resistant infections and also provide baseline information for industrial applications.

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Plant mediated nanoparticles' synthesis has led to a remarkable progress via unfolding a green synthesis protocol towards nanoparticles' synthesis. It seems to have drawn quite an unequivocal attention with a view of reformulating the novel strategies as alternatives for popular conventional methods. Hence, the present review summarizes the literature reported thus far and envisions towards plants as emerging sources of nanofactories.