Putative Role of Anti-microbial Peptide Recovered from Lactiplantibacillus spp. in Biocontrol Activity.

Antimicrobial peptides (AMPs) stand as a promising alternative to conventional pesticides, leveraging a multifaceted approach to combat plant pathogens. This study focuses on identifying and characterizing the AMP produced by Lactiplantibacillus argentoratensis strain IT, demonstrating potent antibacterial activity against various harmful microorganisms. Evaluation of AMPs' antibacterial activity was conducted through an agar well diffusion assay, a reliable method for assessing secondary metabolite antimicrobial efficacy. The study unveils the antimicrobial potential of the purified extract obtained from Lactiplantibacillus argentoratensis IT, isolated from goat milk. Notably, the AMP exhibited robust antibacterial activity against phytopathogens affecting solanaceous crops, including the Gram-negative Ralstonia solanacearum. Expression conditions and purification methods were optimized to identify the peptide's mass and sequence, utilizing LC-MS and SDS-PAGE. This paper underscores the application potential of Lactiplantibacillus spp. IT as a biocontrol agent for managing bacterial infectious diseases in plants. Results indicate optimal AMP production at 37 °C, with a culture broth pH of 5 during fermentation. The obtained peptide sequence corresponded to peaks at 842.5 and 2866.4 m/z ratio, with a molecular weight of approximately 5 kDa according to tricine SDS-PAGE analysis. In conclusion, this study lays the foundation for utilizing Lactiplantibacillus spp. IT derived AMPs in plant biocontrol strategies, showcasing their efficacy against bacterial phytopathogens. These findings contribute valuable insights for advancing sustainable agricultural practices.

Deciphering the fertilizing and disease suppression potential of phytofabricated zinc oxide nanoparticles on Brassicajuncea.

Every year 30-50% of crops suffer from fungal and bacterial diseases. Use of various chemically synthesized fungicides and bactericides make the soil environment more toxic and harmful to the plant health. Therefore, there is need to find non-toxic and cost effective alternative against plant pathogen. In recent years, nanotechnology has got attention because of its wide application in different areas of agriculture. Various nanoparticles have been used in agriculture for their fertilizing and antimicrobial potential. Among them zinc oxide nanoparticles (ZnO NPs) have gained the attention of agriculturists as zinc is an essential micronutrient for plants. Antifungal activity of Tb-ZnO NPs (Terminalia bellerica synthesized zinc oxide nanoparticles) against Alternaria brassicae causative agent of blight disease in Brassica juncea has been reported in our previous study. To use Tb-ZnO NPs as nanofungicides and simultaneously as nanofertilizers, the doses of Tb-ZnO NPs beneficial to the Brassica juncea crop is need to be known. Therefore, experiment has been designed to see the protective and curative potential of Tb-ZnO NPs in alluvial and calcareous soil. Biochemical constituents and stress enzymes analysis has shown significant potential of Tb-ZnO NPs at 200 ppm concentration in alleviating the stress caused by A. brassicae by modulating the photosynthetic, biochemical and enzymatic characteristics. Growth parameter analysis confirmed the role of Tb-ZnO NPs in increasing root and shoot length of B. juncea. Yield component such as seed number, seed weight and oil content of B. juncea crop also has been increased. There was one-fold increase in oil content of B. juncea as compared to control. Maximum percent disease control was found to be 70% in alluvial soil (protective method) grown plants. Therefore, present study supports the hypothesis of a relationship between nutrients and disease suppression.

Isolation and Characterization of a Novel Laccase-Producing Bacteria Bhargavaea beijingensis from Paper and Pulp Effluent-Treated Soil Using In Silico Approaches.

Laccases (EC 1.10.3.2) are considered one of the most prominent multicopper enzymes that exhibit the inherent properties of oxidizing a range of phenolic substrates. Mostly, reported laccases have been isolated from the plants and fungi species, whereas bacterial laccases are yet to be explored. Bacterial laccases have numerous distinctive properties over fungal laccases, including stability at high temperatures and high pH. This study includes the isolation of bacteria through the soil sample collected from the paper and pulp industry; the highest laccase-producing bacteria was identified as Bhargavaea bejingensis, using 16S rRNA gene sequencing. The extracellular and intracellular activities after 24 h incubation were 1.41 U/mL and 4.95 U/mL, respectively. The laccase-encoding gene of the bacteria was sequenced; moreover, the in vitro translated protein was bioinformatically characterized and asserted that the laccase produced by the bacteria Bhargavaea bejingensis was structurally and sequentially homologous to the CotA protein of Bacillus subtilis. The enzyme laccase produced from B. bejingensis was classified as three-domain laccase with several copper-binding residues, where a few crucial copper-binding residues of the laccase enzyme were also predicted.

Exploring the intersection of Aspergillus fumigatus biofilms, infections, immune response and antifungal resistance.

Aspergillus fumigatus is an opportunistic pathogen that primarily affects the lungs and frequently elicits an allergic immune response in human hosts via inhalation of its airborne asexual spores (conidia). In immunocompromised individuals, the conidia of this fungus can germinate in the lung and result in severe systemic infections characterised by widespread tissue and organ damage. Conversely, in healthy hosts, the innate immune system is instrumental in eliminating the conidia and preventing disease progression. As with numerous other pathogenic fungi, A. fumigatus possesses a set of virulence factors that facilitate its infective mechanism and the circumvention of immune defences in susceptible hosts. The intrinsic capacity of A. fumigatus to form complex 3D-structured biofilms, both on biotic and abiotic surfaces, represents a key determinant of its evasion of the host immune system and resistance to antifungal drugs. This review delineates the pivotal role of A. fumigatus biofilm structure and function as a significant virulence factor in pathogenic infections, such as aspergilloma and invasive pulmonary aspergillosis (IPA). Additionally, we discuss the importance for the development of novel antifungal drugs as drug-resistant strains continue to evolve. Furthermore, co-infections of A. fumigatus with other nosocomial pathogens have a substantial impact on patient's health outcomes. In this context, we provide a brief overview of COVID-19-associated pulmonary aspergillosis (CAPA), a recently documented condition that has gained attention due to its associated high degree of severity.

Seed biopriming with potential bioagents influences physiological processes and plant defense enzymes to ameliorate sheath blight induced yield loss in rice (Oryza sativa L.).

Disease management with the use of conventional pesticides has emerged as a major threat to the environment and human health. Moreover, the increasing cost of pesticides and their use in staple crops such as rice is not economically sustainable. The present study utilized a combination of two commercial powder formulations of biocontrol agents, Trichoderma harzianum (Th38) and Pseudomonas fluorescens (Pf28) to induce resistance against sheath blight disease via seed biopriming in basmati rice variety Vasumati and compared the performance with systemic fungicide carbendazim. Sheath blight infection significantly increased the levels of stress indicators such as proline (0.8 to 4.25 folds), hydrogen peroxide (0.89 to 1.61 folds), and lipid peroxidation (2.4 to 2.6 folds) in the infected tissues as compared to the healthy control. On the contrary, biopriming with biocontrol formulation (BCF) significantly reduced the level of stress markers, and substantially enhanced the levels of defense enzymes such as peroxidase (1.04 to 1.18 folds), phenylalanine ammonia lyase (1.02 to 1.17 folds), lipoxygenase (1.2 to 1.6 folds), and total phenolics (74% to 83%) as compared to the infected control. Besides, improved photosynthesis (48% to 59%) and nitrate reductase activity (21% to 42%) showed a positive effect on yield and biomass, which compensated disease induced losses in bio-primed plants. Conversely, the comparative analysis of the efficacy levels of BCF with carbendazim revealed BCF as a potential and eco-friendly alternative for reducing disease impact and maintaining higher yield in rice under sheath blight infection.

High level of persister frequency in clinical staphylococcal isolates.

BACKGROUND: Staphylococcus aureus is a notorious human pathogen that causes often lethal systemic conditions that are mostly medical device associated biofilm infections. Similarly, coagulase negative staphylococci are emerging as leading pathogen for nosocomial infections owing to their ability to form biofilm on implanted medical equipment. Chronic in nature, these infections are difficult to treat. Such recalcitrance of these infections is caused mainly due to the presence of persister cells, which exhibit transient yet extreme tolerance to antibiotics. Despite tremendous clinical significance, there is lack of studies on persister cells formation among clinical bacterial isolates. Considering the importance of factors influencing persister formation, in this study, we evaluate the association of antibiotic tolerance with biofilm production, antibiotic stress, growth phase, specimen type, and dependency on staphylococcal species. Biofilm formation was detected among 375 clinical staphylococcal isolates by quantitative tissue culture plate method (TCP) and icaAD genes by genotypic method. The antibiotic susceptibility was determined by Kirby Bauer disc diffusion method while minimum inhibitory concentration values were obtained by agar dilution method. Persister cells were measured in the susceptible staphylococcal isolates in the presence of clinically relevant antibiotics. RESULTS: In the study, 161 (43%) S. aureus and 214 (57%) coagulase negative staphylococci (CNS) were isolated from different clinical samples. TCP method detected biofilm production in 84 (52.2%) S. aureus and 90 (42.1%) CNS isolates. The genotypic method detected icaAD genes in 86 (22.9%) isolates. Majority (> 90%) of both the biofilm producers and non-producers were sensitive to chloramphenicol and tetracycline but were resistant to penicillin. Interestingly, all isolates were sensitive to vancomycin irrespective of biofilm production. While high persister frequency was observed among all staphylococci isolates in the stationary growth phase, the persister frequency in exponential growth phase was statistically high among isolates possessing icaAD genes compared to icaAD negative isolates. CONCLUSION: The research findings provide strong evidence that the clinical staphylococcal isolates exhibit extreme antibiotic tolerance suggesting their causal link with treatment failures. Understanding the factors influencing the formation and maintenance of persister cells are of utmost important aspect to design therapeutics and control recalcitrant bacterial infections.

Bioprospecting uncultivable microbial diversity in tannery effluent contaminated soil using shotgun sequencing and bio-reduction of chromium by indigenous chromate reductase genes.

The tannery industry generates a consequential threat to the environment by producing a large amount of potentially toxic metal-containing waste. Bioremediation has been a promising approach for treating potentially toxic metals, but the efficiency of remediation in microbes is one of the factors limiting their application in tanneries waste treatment. The motivation behind the present work was to explore the microbial diversity and chromate reductase genes present in the tannery effluent-contaminated soil using metagenomics approach. The use of shotgun sequencing enabled the identification of operational parameters that influence microbiome composition and their ability to reduce Chromium (Cr) concentration. The Cr concentration in Kanpur tannery effluent contaminated soil sample was 700 ppm which is many folds than the approved permissible limit by World Health Organisation (WHO) for Cr is 100 ppm. Metagenomic Deoxyribo Nucleic Acid (DNA) was extracted to explore taxonomic community structure, phylogenetic linkages, and functional profile. With a Guanine-Cytosine (GC) abundance of 54%, total of 45,163,604 high-quality filtered reads were obtained. Bacteria (83%), Archaebacteria (14%), and Viruses (3%) were discovered in the structural biodiversity. Bacteria were classified to phylum level, with Proteobacteria (52%) being the dominant population, followed by Bacteriodetes (15%), Chloroflexi (15%), Spirochaetes (7%), Thermotogae (5%), Actinobacteria (4%), and Firmicutes (1%). The OXR genes were cloned and checked for their efficiency to reduce Cr concentration. Insitu validation of OXR8 gene showed a reduction of Cr concentration from 700 ppm to 24 ppm in 72 h (96.51% reduction). The results of this study suggests that there is a huge reservoir of microbes and chromate reductase genes which are unexplored yet.

Exploring the Impact of Bioformulated Copper Oxide Nanoparticles on Cytomorphology of Alternaria brassicicola.

Black leaf spot of Brassica species is caused by a foliar pathogen Alternaria brassicicola (A. brassicicola), the noxious killer of mustard, cabbage, and cauliflower crops. The current investigation involved the synthesis of copper oxide nanoparticles (CuO NPs) from potential strain of Trichoderma harzianum (T. harzianum). Characterization of CuO NPs was performed by UV-vis, FTIR, XRD, SEM-EDX, and HR-TEM studies. UV-visible spectra showed an absorption peak at 275 nm. FTIR study revealed the presence of N-H bonds which could be due to the presence of enzymes and secondary metabolites released in the filtrate of T. harzianum. SEM and HR-TEM revealed the cube shape CuO NPs formed and average particle size was in the range of 31-45 nm. Poisoned food technique was used to check the antifungal efficacy of CuO NPs against A. brassicicola at various concentrations (0.025, 0.050, 0.1, and 0.15 mg/mL). In vitro assays carried on potato dextrose agar showed maximum antifungal activity at 0.15 mg/mL. The control sample have cylindrical and oblong shape conidia, while transverse septation was 2-4 in untreated population. The lower concentrations of CuO NPs (0.025 and 0.050 mg/mL) caused malformed spherical shape conidia with excessive septation, while its higher concentrations (0.1 and 0.15 mg/mL) leads to viability loss in fungal culture. Results indicated that a higher concentration of CuO NPs serve as an effective biocidal concentration for the control of phytopathogens.

Phytofabricated zinc oxide nanoparticles as a nanofungicide for management of Alternaria blight of Brassica.

Plant pathogens resistant to the commercially available fungicides and bactericides even at higher concentrations are the biggest challenge for the farmers to control the losses due to plant diseases. The antibacterial and antifungal potential of nanomaterials makes them a suitable candidate for the control of plant diseases. Thus, the present study reports the phytofabricated zinc oxide nanoparticles (ZnO Np's) using aqueous plant leaf extract of Terminalia bellerica (Baheda). Characterization of ZnO nanoparticles was done by ultraviolet-visible (UV-Vis) studies, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR) analysis, and transmission electron microscopy (TEM). The presence of pure hexagonal wurtzite crystalline structure of ZnO nanoparticles was confirmed by XRD analysis. The TEM images revealed the spherical to hexagonal shaped ZnO nanoparticles with sizes ranging from 20 to 30 nm. The stabilization of synthesized ZnO nanoparticles through the interactions of terpenoids, steroids, phenylpropanoids, flavonoids, phenolic acids, and enzymes present in the leaf extract was suggested by FTIR analysis. The mechanism of the formation of ZnO nanoparticles using Terminalia bellerica (Baheda) (Tb-ZnO Np's) as a bioactive compound is proposed. These phytofabricated ZnO nanoparticles (Tb-ZnO Np's) have shown significant antifungal potential against Alternaria brassicae the causal agent of Alternaria blight disease/leaf spot disease in Brassica species. The microscopic results confirm the changes in mycelium morphology and reduction in the number of spore germination at 0.2 mg/mL concentration Tb-ZnO Np's.

Phenotypic and genotypic characterization of biofilm producing clinical coagulase negative staphylococci from Nepal and their antibiotic susceptibility pattern.

BACKGROUND: Coagulase-negative staphylococci (CNS) survive as commensals of skin, anterior nares and external canals of human and were regarded as non-infectious pathogens. However, they are emerging as a major cause of nosocomial infectious due to their ability to form biofilms and high resistance to several classes of antibiotics. This study examines the biofilm forming abilities of 214 clinical CNS isolates using phenotypic and genotypic methods, and determines their antibiotic susceptibility patterns. METHODS: A total of 214 clinical isolates collected from different clinical samples were identified as CNS and their antibiotic susceptibility determined by CLSI guidelines. The biofilm forming ability of all isolates was determined by three phenotypic methods; Congo red agar (CRA) method, tube adherence method (TM) and tissue culture plate (TCP) method and by genotypic method for the detection of icaAD genes. RESULTS: Among all the isolates, S. epidermidis (57.5%) was found the most frequently, followed by S. saprophyticus (18.7%), S. haemolyticus (11.2%), S. hominis (7%), and S. capitis (5.6%). Antibiotic susceptibility pattern demonstrated 91.6% isolates were resistant to penicillin and 66.8% to cefoxitin while 91.1% isolates were susceptible to chloramphenicol. Constitutive and inducible clindamycin resistant phenotype as measured by D-test was seen among 28% and 14.5% of isolates respectively. Tissue culture plate method detected biofilm production in 42.1% isolate followed by 31.8% through tube method while 20.1% isolates were found to produce slime in Congo red agar method. The genotypic assay revealed presence of icaA and icaD genes in 19.2% isolates. CONCLUSION: The study shows a high prevalence of biofilm formation and inducible clindamycin resistance in CNS isolates, indicating the importance of in-vitro biofilm production test and D-test in routine laboratory diagnostics. Implementation of efficient diagnostic techniques for detection of biofilm production in clinical samples can help manage staphylococcal infections and minimize risks of treatment failures in hospitals.

Diversity of Bacterial Endophytes of Maize (Zea mays) and Their Functional Potential for Micronutrient Biofortification.

Microorganisms due, to their immense metabolic diversity, have the potential to augment the uptake of iron and zinc in addition to other important nutrients in plants. In the present work, 129 different strains of endophytic bacteria were retrieved from stems and leaves of maize. Qualitative screening of these endophytes showed that 24.5% of these isolates were siderophore producers, while 14% could solubilize insoluble zinc compounds and 33% of them had phytase activity. Based on zinc solubilization efficiency and siderophore production ability, 10 isolates each from zinc solubilizers and siderophore producers were selected. Molecular identification indicated that the selected bacteria belonged to diverse genera Microbacterium, Pseudonocardia, Bacillus, Cellulosimicrobium, Staphylococcus, Luteimonas, Bordetella, Brevundimonas, Streptomyces, Cupriavidus, Sphingomonas, Ralstonia, Ochrobactrum, Conyzicola, Paenibacillus and Leifsonia. Quantitative analyses of Zn solubilization using Atomic absorption spectrophotometry (AAS) revealed that Microbacterium hydrothermale M10 and M. proteolyticum B2 were potential solubilizers of different forms of insoluble zinc compounds viz. ZnCO3 (56.63-89.88 ppm), ZnO (106.38-120.08 ppm) and ZnS (3.62-5.56 ppm). Similarly, quantitative estimation of siderophore production activity revealed two endophytes viz. Bacillus altitudinis C7 (97.25% siderophore units) and Pseudonocardia alni M29 (92.05% siderophore units) as potential siderophore producers. These endophytes with potential to produce siderophores and phytases and ability to solubilize zinc can be an important starting material for trials on field to improve Fe and Zn content in edible portion of food crops.

The molecular mechanism of vernalization in Arabidopsis and cereals: role of Flowering Locus C and its homologs.

Winter varieties of plants can flower only after exposure to prolonged cold. This phenomenon is known as vernalization and has been widely studied in the model plant Arabidopsis thaliana as well as in monocots. Through the repression of floral activator genes, vernalization prevents flowering in winter. In Arabidopsis, FLOWERING LOCUS C or FLC is the key repressor during vernalization, while in monocots vernalization is regulated through VRN1, VRN2 and VRN3 (or FLOWERING LOCUS T). Interestingly, VRN genes are not homologous to FLC but FLC homologs are found to have a significant role in vernalization response in cereals. The presence of FLC homologs in monocots opens new dimensions to understand, compare and retrace the evolution of vernalization pathways between monocots and dicots. In this review, we discuss the molecular mechanism of vernalization-induced flowering along with epigenetic regulations in Arabidopsis and temperate cereals. A better understanding of cold-induced flowering will be helpful in crop breeding strategies to modify the vernalization requirement of economically important temperate cereals.

Extremophile - An Adaptive Strategy for Extreme Conditions and Applications.

The concurrence of microorganisms in niches that are hostile like extremes of temperature, pH, salt concentration and high pressure depends upon novel molecular mechanisms to enhance the stability of their proteins, nucleic acids, lipids and cell membranes. The structural, physiological and genomic features of extremophiles that make them capable of withstanding extremely selective environmental conditions are particularly fascinating. Highly stable enzymes exhibiting several industrial and biotechnological properties are being isolated and purified from these extremophiles. Successful gene cloning of the purified extremozymes in the mesophilic hosts has already been done. Various extremozymes such as amylase, lipase, xylanase, cellulase and protease from thermophiles, halothermophiles and psychrophiles are of industrial interests due to their enhanced stability at forbidding conditions. In this review, we made an attempt to point out the unique features of extremophiles, particularly thermophiles and psychrophiles, at the structural, genomic and proteomic levels, which allow for functionality at harsh conditions focusing on the temperature tolerance by them.

Biopriming with Piriformospora indica ameliorates cadmium stress in rice by lowering oxidative stress and cell death in root cells.

Piriformospora indica is known for plant growth promotion and abiotic stress alleviation potential in several agricultural crops. However, a systemic analysis is warranted to explore potential application of this important fungus to augment heavy metal tolerance in rice. The present study explores potential of P. indica in ameliorating the effect of cadmium (Cd) stress in rice cultivars N22 and IR64. Seedlings inoculated with P. indica recorded significantly higher root-shoot length and biomass as compared to non-inoculated plants under control and Cd stress, respectively. Moreover, P. indica inoculated stressed roots accumulated more Cd as compared to non-inoculated stressed roots in both the varieties. Interestingly, cell death and reactive oxygen species (ROS) accumulation were significantly lower in the inoculated plant roots as compare with non-inoculated roots under Cd stress. The results emphasized significantly higher accumulation of Cd in fungal spores could reduce ROS accumulation in root cells resulting in lower cell death.

PGPR-mediated expression of salt tolerance gene in soybean through volatiles under sodium nitroprusside.

Increasing evidence shows that nitric oxide (NO), a typical signaling molecule plays important role in development of plant and in bacteria-plant interaction. In the present study, we tested the effect of sodium nitroprusside (SNP)-a nitric oxide donor, on bacterial metabolism and its role in establishment of PGPR-plant interaction under salinity condition. In the present study, we adopted methods namely, biofilm formation assay, GC-MS analysis of bacterial volatiles, chemotaxis assay of root exudates (REs), measurement of electrolyte leakage and lipid peroxidation, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for gene expression. GC-MS analysis revealed that three new volatile organic compounds (VOCs) were expressed after treatment with SNP. Two VOCs namely, 4-nitroguaiacol and quinoline were found to promote soybean seed germination under 100 mM NaCl stress. Chemotaxis assay revealed that SNP treatment, altered root exudates profiling (SS-RE), found more attracted to Pseudomonas simiae bacterial cells as compared to non-treated root exudates (S-RE) under salt stress. Expression of Peroxidase (POX), catalase (CAT), vegetative storage protein (VSP), and nitrite reductase (NR) genes were up-regulated in T6 treatment seedlings, whereas, high affinity K+ transporter (HKT1), lipoxygenase (LOX), polyphenol oxidase (PPO), and pyrroline-5-carboxylate synthase (P5CS) genes were down-regulated under salt stress. The findings suggest that NO improves the efficiency and establishment of PGPR strain in the plant environment during salt condition. This strategy may be applied on soybean plants to increase their growth during salinity stress.

Induced drought tolerance through wild and mutant bacterial strain Pseudomonas simiae in mung bean (Vigna radiata L.).

The present study focused on the overproducing mutant of a plant growth promoting rhizobacterium (PGPR) Pseudomonas simiae strain AU (MTCC-12057) for significant drought tolerance in mung bean plants. Five mutants namely AU-M1, AU-M2, AU-M3, AU-M4 and AU-M5 were made after treatment of wild type strain with N-methyl-N-nitro-N-nitrosoguanidine. Mutant strain AU-M4 was recorded for enhanced ACC deaminase (ACC-D) activity, indole acetic acid (IAA) production and inorganic phosphate (Pi) solubilization compared to wild strain and other four mutant strains under drought condition. AU-M4 showed higher phosphate solubilization index (8.17) together with higher ACC-D activity (98 nmol/mg/h) and IAA concentration (69.35 µg/ml) compared with the wild type P. simiae strain AU ACC-D activity (79 nmol/mg/h) and IAA concentration (38.98 µg/ml) respectively. In this report, we investigated the effect of both wild and mutant type bacterial strain on mung bean plants under drought stress. Results showed that mutant AU-M4 and wild type strain AU inoculated plants exhibited superior tolerance against drought stress, as shown by their enhanced plant biomass (fresh weight), higher water content, higher proline accumulation and lower osmotic stress injury. Mutant AU-M4 and wild strain AU inoculated plants reduced the ethylene level by 59 and 45% respectively, compared to the control under stress condition. Furthermore, bacterial inoculated plants showed enhanced induced systemic drought tolerance by reducing stomata size and net photosynthesis resulting higher water content in mung bean plants that may help in survival of plants during drought condition. To mitigate the effects of drought stress, use of PGPR will be needed to ensure sufficient production of food from crop plants. Taking current leads available, concerted future research is needed in this area, particularly on field evaluation with application of potential microorganisms.

Dual symbiosis between Piriformospora indica and Azotobacter chroococcum enhances the artemisinin content in Artemisia annua L.

At present, Artemisia annua L. is the major source of artemisinin production. To control the outbreaks of malaria, artemisinin combination therapies (ACTs) are recommended, and hence an ample amount of artemisinin is required for ACTs manufacture to save millions of lives. The low yield of this antimalarial drug in A. annua L. plants (0.01-1.1%) ensues its short supply and high cost, thus making it a topic of scrutiny worldwide. In this study, the effects of root endophyte, Piriformospora indica strain DSM 11827 and nitrogen fixing bacterium, Azotobacter chroococcum strain W-5, either singly and/or in combination for artemisinin production in A. annua L. plants have been studied under poly house conditions. The plant growth was monitored by measuring parameters like height of plant, total dry weight and leaf yield with an increase of 63.51, 52.61 and 79.70% respectively, for treatment with dual biological consortium, as compared to that of control plants. This significant improvement in biomass was associated with higher total chlorophyll content (59.29%) and enhanced nutrition (especially nitrogen and phosphorus, 55.75 and 86.21% respectively). The concentration of artemisinin along with expression patterns of artemisinin biosynthesis genes were appreciably higher in dual treatment, which showed positive correlation. The study suggested the potential use of the consortium P. indica strain DSM 11827 and A. chroococcum strain W-5 in A. annua L. plants for increased overall productivity and sustainable agriculture.

WRKY6 restricts Piriformospora indica-stimulated and phosphate-induced root development in Arabidopsis.

BACKGROUND: Arabidopsis root growth is stimulated by Piriformospora indica, phosphate limitation and inactivation of the WRKY6 transcription factor. Combinations of these factors induce unexpected alterations in root and shoot growth, root architecture and root gene expression profiles. RESULTS: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant. This is associated with the stimulation of PHOSPHATE1 expression and ethylene production. Expression profiles from the roots of wrky6 seedlings identified genes involved in hormone metabolism, transport, meristem, cell and plastid proliferation, and growth regulation. 25 miRNAs were also up-regulated in these roots. We generated and discuss here a list of common genes which are regulated in growing roots and which are common to all three growth stimuli investigated in this study. CONCLUSION: Since root development of wrky6 plants exposed to P. indica under phosphate limitation is strongly promoted, we propose that common genes which respond to all three growth stimuli are central for the control of root growth and architecture. They can be tested for optimizing root growth in model and agricultural plants.

An ecological role of fungal endophytes to ameliorate plants under biotic stress.

It is our consensus that plants survive and flourish in stressed ecosystems because of endosymbiotic organisms that have co-evolved and were essential for their adaptation to changing environments. Some of these microbial components are noncultivable and vertically transmitted from generation to generation. They represent a vast reservoir of heritable DNA that can enhance plant performance in changing environments and add genetic flexibility to adaptation of long-lived plants. If such endophytes can be identified that not only persist in progeny of novel hosts, but can confer benefits in mechanized, agricultural systems, they would be increasingly important in agricultural production and lead to a rapid and economical method of providing novel germplasms of native and crop plants. In the present review, authors advocate the deployment of fungal diversity and its role to overcome the biotic stress in plants. Endophytic fungal association with plants helps it to protect from various pathogen and pests and adapt to survive in harsh biotic and abiotic stress condition.

Facile Algae-Derived Route to Biogenic Silver Nanoparticles: Synthesis, Antibacterial, and Photocatalytic Properties.

Biogenic synthesis of metal nanoparticles is of considerable interest, as it affords clean, biocompatible, nontoxic, and cost-effective fabrication. Driven by their ability to withstand variable extremes of environmental conditions, several microorganisms, notably bacteria and fungi, have been investigated in the never-ending search for optimal nanomaterial production platforms. Here, we present a hitherto unexplored algal platform featuring Chlorella pyrenoidosa, which offers a high degree of consistency in morphology of synthesized silver nanoparticles. Using a suite of characterization methods, we reveal the intrinsic crystallinity of the algae-derived nanoparticles and the functional moieties associated with its surface stabilization. Significantly, we demonstrate the antibacterial and photocatalytic properties of these silver nanoparticles and discuss the potential mechanisms that drive these critical processes. The blend of photocatalytic and antibacterial properties coupled with their intrinsic biocompatibility and eco-friendliness make these nanoparticles particularly attractive for wastewater treatment.