Fungal Plant Research Articles

Airborne bacteria and fungi in a wastewater treatment plant: type and characterization of bio-aerosols, emission characterization and mapping

Airborne bacteria and fungi in a wastewater treatment plant: type and characterization of bio-aerosols, emission characterization and mapping

PLANT-ASSOCIATED ENDOPHYTIC FUNGI: A SOURCE OF STRUCTURALLY DIVERSE AND BIOACTIVE NATURAL PRODUCTS

Plant-associated endophytes are producing important and unique secondary metabolites, and their outstanding biosynthetic process seems to be prospective avenues for phytochemists. This review summarized and updated novel natural compounds from endophytic fungi of plants and herbs focusing on the various of fungi genera. The fungal taxonomy, diversity, location, and biological activities have been reported. The results showed 138 new secondary metabolites isolated from 40 species of fungal strains belonging to 13 genera and six phyla. The present review will be heplful for scientists in the fields of phytochemistry, organic chemistry, and microbiology.

Inorganic phosphorus nutrition in green-leaved terrestrial orchid seedlings.

Many terrestrial orchids have an obligate dependence on their mycorrhizal associations for nutrient acquisition, particularly during germination and early seedling growth. Though important in plant growth and development, phosphorus (P) nutrition studies in mixotrophic orchids have been limited to only a few orchid species and their fungal symbionts. For the first time, we demonstrate the role of a range of fungi in the acquisition and transport of inorganic P to four phylogenetically distinct green-leaved terrestrial orchid species (Diuris magnifica, Disa bracteata, Pterostylis sanguinea and Microtis media subsp. media) that naturally grow in P-impoverished soils. Mycorrhizal P uptake and transfer to orchids was determined and visualized using agar microcosms with a diffusion barrier between P source (33P orthophosphate) and orchid seedlings, allowing extramatrical hyphae to reach the source. Extramatrical hyphae of the studied orchid species were effective in capturing and transporting inorganic P into the plant. Following 7 d of exposure, between 0.5 % (D. bracteata) and 47 % (D. magnifica) of the P supplied was transported to the plants (at rates between 0.001 and 0.097 fmol h-1). This experimental approach was capable of distinguishing species based on their P-foraging efficiency, and highlighted the role that fungi play in P nutrition during early seedling development. Our study shows that orchids occurring naturally on P-impoverished soils can obtain significant amounts of inorganic P from their mycorrhizal partners, and significantly more uptake of P supplied than previously shown in other green-leaved orchids. These results provide support for differences in mycorrhiza-mediated P acquisition between orchid species and fungal symbionts in green-leaved orchids at the seedling stage. The plant-fungus combinations of this study also provide evidence for plant-mediated niche differentiation occurring, with ecological implications in P-limited systems.

Utilization of Mother Nature’s Gift for the Biofabrication of Copper/ Copper Oxide Nanoparticles for Therapeutic Applications

Abstract: This review enumerates the green cum biosynthesis of copper/copper oxide nanoparticles (Cu/CuO NPs) using plant and biogenic extracts. Moreover, it explores the biogenic synthesis of Cu/CuO NPs using different methods and elaborates on biological and eco-friendly modes of synthesis using different plant species. The survey revealed that biological methods involve the use of plant extracts, bacteria, protozoa and fungi. However, plant mediated nanomaterials synthesis is the best technique. Some of the microscopic characterization techniques, like XRD, SEM, TEM, FTIR, XPS, BET and UV–Vis, have been discussed to explore the size, shape, structure, composition and porosity of Cu NPs. The current review highlights the phytosynthesis, characterization and therapeutic applications of Cu/CuO NPs. The therapeutic applications of Cu/CuO NPs, like antimicrobial, anti-parasitic and anticancer activities against a variety of gram-negative and positive bacteria, fungi and human cancer cells, respectively, have been discussed. Keywords: Biosynthesis, Phytosynthesis, Cu/CuO NPs, Microscopic techniques; Therapeutic applications.

A New Source of Diterpene Lactones From Andrographis paniculata (Burm. f.) Nees-Two Endophytic Fungi of Colletotrichum sp. With Antibacterial and Antioxidant Activities.

Endophytic fungi of medicinal plants are abundant, and their metabolites often have antioxidant, antibacterial, and antitumor effects and can produce secondary metabolites identical or similar to those of their hosts, which can mitigate the problem of insufficient supply of medicinal plants. In this study, we screened endophytic fungi for strains that produce the same diterpene lactones as Andrographis paniculata based on their biological activity. Firstly, the dominant group of endophytic fungi of Andrographis paniculata was screened and pathogenicity was studied using Koch’s rule. Secondly, DPPH, ABTS, OH, PTIO radical scavenging, and FRAP assays were used to detect the antioxidant activity of the extracellular extracts of the strains, and total phenol and total flavonoid contents of the strains with high antioxidant capacity were determined. S. aureus, B. subtilis, E. coli, and P. aeruginosa were used to determine the antibacterial activity of the mycelial extracts of the strains. Finally, the secondary metabolites of the mycelial extracts of the strains were examined by high-performance liquid chromatography. The results showed that 32 strains of Andrographis paniculata were relatively isolated > 70% and non-pathogenic. Extracellular extracts of strains AP-1 and AP-4 showed vigorous antioxidant activity, and AP-4, AP-12, AP-47, and AP-48 showed antibacterial activity against four strains of bacteria. The HPLC results indicated that the mycelial extracts of AP-4 and AP-12 contained diterpene lactones. The two endophytic fungi were recognized as Colletotrichum sp. The study successfully obtained diterpene lactones from the endophytic fungus of Andrographis paniculata and confirmed the feasibility of using endophytic fungal strains to produce active substances consistent with the host. It was also useful for exploring endophytic fungi and medicinal plants. The relationship provides theoretical guidance.

Increasing atmospheric CO2 differentially supports arsenite stress mitigating impact of arbuscular mycorrhizal fungi in wheat and soybean plants

Arbuscular mycorrhizal fungi (AMF) are beneficial for the plant growth under heavy metal stress. Such beneficial effect is improved by elevated CO2 (eCO2). However, the mechanisms by which eCO2 improves AMF symbiotic associations under arsenite (AsIII) toxicity are hardly studied. Herein, we compared these regulatory mechanisms in species from two agronomical important plant families – grasses (wheat) and legumes (soybean). AsIII decreased plant growth (i.e., 53.75 and 60.29% of wheat and soybean, respectively) and photosynthesis. It also increased photorespiration and oxidative injury in both species, but soybean was more sensitive to oxidative stress as indicated by higher H2O2 accumulation and oxidation of protein and lipid. eCO2 significantly improved AMF colonization by increasing auxin levels, which induced high carotenoid cleavage dioxygenase (CCDs) activity, particularly in soybean roots. The improved sugar metabolism in plant shoots by co-application of eCO2 and AsIII allocated more sugars to roots sequentially. Sugar accumulation in plant roots is further induced by AMF, resulting in more C skeletons to produce organic acids, which are effectively exudated into the soil to reduce AsIII uptake. Exposure to eCO2 reduced oxidative damage and this mitigation was stronger in soybean. This could be attributed to a greater reduction in photorespiration as well as a stronger antioxidant and detoxification defence systems. The grass/legume-specificity was supported by principal component analysis, which revealed that soybean was more affected by AsIII stress and more responsive to AMF and eCO2. This study provided a mechanistic understanding of the impact of AMF, eCO2 and their interaction on As-stressed grass and legume plants, allowing better practical strategies to mitigate AsIII phytotoxicity.

Simple attributes predict the value of plants as hosts to fungal and arthropod communities

Fungal and arthropod consumers constitute the vast majority of global terrestrial biodiversity. Yet, the link from richness and composition of producer (plant) communities to the richness of consumer communities is poorly understood. Fungal and arthropod species richness could be a simple function of producer species richness at a site. Alternatively, it could be a complex function of chemical and structural properties of the producer species making up communities. We used databases on plant–fungus and plant–arthropod trophic links to derive the richness of consumer biota per associated plant species (coined link score). We assessed how well link scores could be predicted by simple attributes of plant species. Next, we used a multi‐taxon inventory of 130 sites, representing all major habitat types in a country (Denmark), to investigate whether link scores summed over plant species in communities (coined link sum) could outperform simple plant species richness as predictor of fungal and arthropod richness at the sites. We found plant species' link scores for both fungi and arthropods to be positively related to plant size, regional occupancy, nativeness and ectomycorrhizal status. Link‐based indices generally improved the prediction of richness of fungal and arthropod communities. For fungal communities, both observed link sum (from databases) and predicted link sum (from plant attributes) had high predictive power, while plant richness alone had none. For arthropod communities, predictive performance varied between functional groups. For both fungi and arthropods, richness predictions were further improved by considering abiotic habitat conditions. Our results underline the importance of plants as niche space for the megadiverse groups of arthropods and fungi. The plant–attribute approach holds promise for predicting local and regional consumer richness in areas of the world lacking detailed plant–consumer databases.

The INRAE Centre for Vegetable Germplasm: Geographically and Phenotypically Diverse Collections and Their Use in Genetics and Plant Breeding.

The French National Research Institute for Agriculture, Food and the Environment (INRAE) conserves and distributes five vegetable collections as seeds: the aubergine* (in this article the word aubergine refers to eggplant), pepper, tomato, melon and lettuce collections, together with their wild or cultivated relatives, are conserved in Avignon, France. Accessions from the collections have geographically diverse origins, are generally well-described and fixed for traits of agronomic or scientific interest and have available passport data. In addition to currently conserving over 10,000 accessions (between 900 and 3000 accessions per crop), the centre maintains scientific collections such as core collections and bi- or multi-parental populations, which have also been genotyped with SNP markers. Each collection has its own merits and highlights, which are discussed in this review: the aubergine collection is a rich source of crop wild relatives of Solanum; the pepper, melon and lettuce collections have been screened for resistance to plant pathogens, including viruses, fungi, oomycetes and insects; and the tomato collection has been at the heart of genome-wide association studies for fruit quality traits and environmental stress tolerance.

Design, Synthesis, and Antifungal Activity of Novel Chalcone Derivatives Containing a Piperazine Fragment.

In an attempt to find the biorational pesticides, 20 novel chalcone derivatives containing a piperazine fragment were designed and synthesized. Their fungicidal activities and preliminarily action mechanism against Rhizoctonia solani were evaluated. Strikingly, the biological activity of compound D2 was obtained by optimizing the structure of the system. Subsequently, the practical value of compound D2 was ascertained by the relative surveys on in vivo anti-R. solani and anti-Colletotrichum gloeosporioides. The results revealed by scanning electron microscopy demonstrated that compound D2 could induce irregular and shrivelled growth of mycelium and rupture of the mycelium surface. This study indicates that chalcone derivatives containing a piperazine skeleton had better inhibitory effect on plant fungi, providing further complementary research on new pesticides.

Endophytic Colletotrichum Species from Aquatic Plants in Southwest China.

Colletotrichum species are plant pathogens, saprobes, and endophytes in many economically important hosts. Many studies have investigated the diversity and pathogenicity of Colletotrichum species in common ornamentals, fruits, and vegetables. However, Colletotrichum species occurring in aquatic plants are not well known. During the investigation of the diversity of endophytic fungi in aquatic plants in southwest China, 66 Colletotrichum isolates were obtained from aquatic plants there, and 26 of them were selected for sequencing and analyses of actin (ACT), chitin synthase (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the internal transcribed spacer (ITS) region, and β-tubulin (TUB2) genomic regions. Based on morphological characterization and multi-locus phylogenetic analyses, 13 Colletotrichum species were recognized, namely, C. baiyuense sp. nov., C. casaense sp. nov., C. demersi sp. nov., C. dianense sp. nov., C. fructicola, C. garzense sp. nov., C. jiangxiense, C. karstii, C. philoxeroidis sp. nov., C. spicati sp. nov., C. tengchongense sp. nov., C. vulgaris sp. nov., C. wuxuhaiense sp. nov. Two species complexes, the C. boninense species complex and C. gloeosporioides species complex, were found to be associated with aquatic plants. Pathogenicity tests revealed a broad diversity in pathogenicity and aggressiveness among the eight new Colletotrichum species.

Discovery of microRNA-like Small RNAs in Pathogenic Plant Fungus Verticillium nonalfalfae Using High-Throughput Sequencing and qPCR and RLM-RACE Validation.

Verticillium nonalfalfae (V. nonalfalfae) is one of the most problematic hop (Humulus lupulus L.) pathogens, as the highly virulent fungal pathotypes cause severe annual yield losses due to infections of entire hop fields. In recent years, the RNA interference (RNAi) mechanism has become one of the main areas of focus in plant—fungal pathogen interaction studies and has been implicated as one of the major contributors to fungal pathogenicity. MicroRNA-like RNAs (milRNAs) have been identified in several important plant pathogenic fungi; however, to date, no milRNA has been reported in the V. nonalfalfae species. In the present study, using a high-throughput sequencing approach and extensive bioinformatics analysis, a total of 156 milRNA precursors were identified in the annotated V. nonalfalfae genome, and 27 of these milRNA precursors were selected as true milRNA candidates, with appropriate microRNA hairpin secondary structures. The stem-loop RT-qPCR assay was used for milRNA validation; a total of nine V. nonalfalfae milRNAs were detected, and their expression was confirmed. The milRNA expression patterns, determined by the absolute quantification approach, imply that milRNAs play an important role in the pathogenicity of highly virulent V. nonalfalfae pathotypes. Computational analysis predicted milRNA targets in the V. nonalfalfae genome and in the host hop transcriptome, and the activity of milRNA-mediated RNAi target cleavage was subsequently confirmed for two selected endogenous fungal target gene models using the 5′ RLM-RACE approach.

Four Propiconazole Stereoisomers: Stereoselective Bioactivity, Separation via Liquid Chromatography-Tandem Mass Spectrometry, and Dissipation in Banana Leaves.

In this study, we evaluated the stereoselective bioactivity of four propiconazole stereoisomers against the causal agents of the banana leaf spot disease (Curvularia lunata and Colletotrichum musae). We also evaluated the stereoselective degradation of the stereoisomers in banana leaves under field test conditions. The Superchiral S-OX column successfully separated the four propiconazole stereoisomers. X-ray single-crystal diffraction confirmed that the absolute configuration of the cis-stereoisomer-(+)-A of propiconazole was (2R,4S)-propiconazole and that of the cis-stereoisomer-(-)-A of propiconazole was (2S,4R)-propiconazole. In vitro antibacterial results revealed that (2R,4S)-(+)-propiconazole had the highest activity against the two target plant fungi. In this study, a new and efficient high-performance liquid chromatography tandem mass spectrometry method was developed for the determination of the four stereoisomeric residues of propiconazole in banana leaves. The mean recoveries of the method for the stereoisomers were 76.3-103% with relative standard deviations of 1.25-11.4%. The four propiconazole stereoisomers had a detection limit of 0.002-0.006 mg/kg and a limit of quantification of 0.02-0.03 mg/kg in banana leaves. Propiconazole-(-)-B and propiconazole-(-)-A degraded slightly faster than their corresponding enantiomers propiconazole-(+)-B and propiconazole-(+)-A in banana leaves collected from three typical banana production areas.

The Impact of Drought Stress on Soil Microbial Community, Enzyme Activities and Plants

Nowadays, the most significant consequence of climate change is drought stress. Drought is one of the important, alarming, and hazardous abiotic stresses responsible for the alterations in soil environment affecting soil organisms, including microorganisms and plants. It alters the activity and functional composition of soil microorganisms that are responsible for crucial ecosystem functions and services. These stress conditions decrease microbial abundance, disturb microbial structure, decline microbial activity, including enzyme production (e.g., such as oxidoreductases, hydrolases, dehydrogenase, catalase, urease, phosphatases, β-glucosidase) and nutrient cycling, leading to a decrease in soil fertility followed by lower plant productivity and loss in economy. Interestingly, the negative effects of drought on soil can be minimized by adding organic substances such as compost, sewage slugs, or municipal solid waste that increases the activity of soil enzymes. Drought directly affects plant morphology, anatomy, physiology, and biochemistry. Its effect on plants can also be observed by changes at the transcriptomic and metabolomic levels. However, in plants, it can be mitigated by rhizosphere microbial communities, especially by plant growth-promoting bacteria (PGPB) and fungi (PGPF) that adapt their structural and functional compositions to water scarcity. This review was undertaken to discuss the impacts of drought stress on soil microbial community abundance, structure and activity, and plant growth and development, including the role of soil microorganisms in this process. Microbial activity in the soil environment was considered in terms of soil enzyme activities, pools, fluxes, and processes of terrestrial carbon (C) and nitrogen (N) cycles. A deep understanding of many aspects is necessary to explore the impacts of these extreme climate change events. We also focus on addressing the possible ways such as genome editing, molecular analysis (metagenomics, transcriptomics, and metabolomics) towards finding better solutions for mitigating drought effects and managing agricultural practices under harsh condition in a profitable manner.

Rhizospheric Fungus: Morphological Characterization Of Rhizosphere Flower On Onion Plant In Enrekang District

The control of moler disease caused by Fusarium oxysporum on shallot plants in Enrekang Regency still relies on the use of chemical fungicides. Plants that are symbiotic with microbes will produce phytohormones optimally so that it will trigger the tolerance level of plants to abiotic and biotic stresses including plant pathogens, so it is necessary to explore the rhizosphere fungi of onion plants in Enrekang Regency to identify morphologically. This study used a red onion soil rhizosphere soil sample taken at the shallot farming center in Enrekang Regency, isolation and testing were carried out in the plant disease laboratory of Hasanuddin University. The results achieved were 20 isolates with 5 genera of fungi namely Fusarium on isolates 1,2,4,12 and 13, Gliocladium on isolates number 15,

Advances in the studies on symbiotic arbuscular mycorrhizal fungi of traditional Chinese medicinal plants

Arbuscular mycorrhizal (AM) fungi reside in the rhizosphere and form mutualistic associations with plant roots. They promote photosynthesis, improve stress resistance, and induce secondary metabolite biosynthesis in host medicinal plants. The AM fungi that are symbiotic with medicinal plants comprise a wide array of species and have abundant germplasm resources. Though research on the AM fungi in medicinal plants began relatively recently, it has nonetheless become an investigative hot spot. Several scholars have explored the diversity and the growth-promoting effects of mycorrhizal fungi in hundreds of medicinal plants. Current research on symbiotic AM fungi in medicinal plants has focused mainly on the effects of inoculating host plants with symbiotic mycorrhizal fungi. However, research on the symbiotic AM fungi in medicinal plants continues to expand, and further study is required to determine the mechanisms by which AM fungi interact with host plants. This paper introduces the diversity of symbiotic AM fungi of medicinal plants and the effects of AM fungi on rhizosphere soil of medicinal plants, including soil structure, microbiota, enzyme activities, etc. This review focuses on the effects of AM fungi on medicinal plants, including antioxidant enzyme systems, drought resistance, nutrient absorption profiles of macro- and micronutrients, accumulation of secondary metabolites such as terpenes, phenolic compounds, and nitrogenous compounds, and prevention of diseases. This review is expected to provide a reference for the application of AM fungi in medicinal plant cultivation, biological control, resource conservation, and the sustainable development of the traditional Chinese medicine industry.

Biofabrication of Ag Nanoparticles Using Bacteria, Plant Fungi and Algae and Their Applications in Clinical Gadgets

Biofabrication of Ag Nanoparticles Using Bacteria, Plant Fungi and Algae and Their Applications in Clinical Gadgets

Endophytic Fungi and Secondary Metabolites of Rehmannia Glutinosa Based on Traditional Chinese Medicine Fingerprints.

Research on the active components of medicinal plants has always been the focus of research, and research on the active components of medicinal plant endophytic fungi and their secondary metabolites has also attracted widespread attention. Endophytic fungi of medicinal plants are widely distributed and are ubiquitous in various biological groups in nature. Rehmannia glutinosa contains a variety of active ingredients, which are regarded as the top grade of Chinese medicinal materials. It is of certain significance to study endophytic fungi and their metabolites of Rehmannia glutinosa. In this paper, endophytic fungi and their secondary metabolites of Rehmannia glutinosa were studied using fingerprint technology, which initially understands the diversity of endophytic fungi in Rehmannia glutinosa. In this paper, the roots and leaves of Rehmannia glutinosa were used as experimental materials. The fungi were cultured in the medium, the fungi were isolated and purified by the tissue block method, the fungal growth of Rehmannia glutinosa in different parts was determined, and the types of endophytic fungi were identified by microscopic identification and fingerprinting. The isolated strains were tested for biological activity using oryza oryzae spores, and highly active strains were screened. Fermentation products of endophytic fungi were separated and purified by chromatography, and the structure of the compounds was identified by nuclear magnetic resonance spectroscopy. Through the above studies, the population structure of endophytic fungi of Rehmannia glutinosa was determined, 3 highly active strains were found, and the structures of 7 endophytic fungi metabolites were identified, of which 3 were newly discovered compounds.

Pathogenicity test of sengon (Falcataria moluccana) seed-borne endophytic fungus

The sengon (Falcataria moluccana) is one of the high-economic and highly cultivated industrial plants in Indonesia. Attacks by pests and diseases can affect quality and quantity and thus require effective control. One of the rare sengon plant fungus explorations has been developed. This study aims to find out the pathogenicity of 13 seed-borne endophytic fungi from sengon seeds. The result shows that seven endophytic fungi were pathogenic (Daldinia sp, Curvularia lunata, Sardiomycetes sp. Eremothecium ashbyi, Annulohypoxylon stygium. Arthrinium malaysianum, Annulohypoxylon nitens) and six non-pathogenic (Onchroconis humicola, Cladophialophora boppii, Aspergillus ruber, Aspergillus chevalieri, Ascotricha sp., and not identified fungi). Thus the isolated endophytic fungi mainly were potentially pathogenic. Among the six species of non-pathogenic endophytic fungi, O. humicola is better able to increase the increase of plumules, radicals, cotyledons, and leaves higher than six other isolates

Synthesis of bioactive fluoropyrrolidines via copper(i)-catalysed asymmetric 1,3-dipolar cycloaddition of azomethine ylides.

Chiral pyrrolidinyl units are important building blocks in biologically active natural products and drugs, and the development of efficient methods for the synthesis of diverse structured pyrrolidine derivatives is of great importance. Meanwhile, incorporating fluorine containing groups into small molecules often changes their activities to a great extent due to the special physicochemical properties of fluorine atoms. Herein, we report an efficient route to obtain enantioenriched 3,3-difluoro- and 3,3,4-trifluoropyrrolidinyl derivatives by Cu(i)-catalysed enantioselective 1,3-dipolar cycloaddition of azomethine ylides with less active 1,1-difluoro- and 1,1,2-trifluorostyrenes. A series of new fluorinated pyrrolidines have been prepared in high yields (up to 96%) and with excellent stereoselectivities (up to >20 : 1 dr and 97% ee), and these unique structural blocks could be readily introduced into some natural compounds and pharmaceuticals. Additionally, antifungal activity investigation against four common plant fungi showed that some products possess general and high biological activities; comparison with the low antifungal activities of corresponding nonfluorinated compounds revealed that the fluorine atoms at the pyrrolidinyl rings play a crucial role in the antifungal activity.

Antimicrobial Activity of Zinc Oxide Nanoparticles Synthesized Using Leaves Extract of Abies webbiana

Introduction: Green synthesis of nanoparticles using plant extract, bacteria, fungi and enzymes are eco-friendly and cost effective which do need high pressure, energy, temperature and toxic chemicals for its synthesis protocol. Zinc oxide nanoparticles have various physical, chemical and biological properties which can be applied in the treatment of oral diseases.
 Aim: The main objective of the current study was to synthesize the zinc oxide nanoparticles (ZnO NPs) in a cost effective biological method. The extract of A. webbiana was used to synthesis Zinc oxide nanoparticles.
 Materials and Methods: In this report, we used the extract of A. webbiana to synthesize zinc oxide nanoparticles and were characterized using U-V visible spectrophotometer and were tested for their antimicrobial activity against oral pathogens.
 Results: These biosynthesized zinc oxide nanoparticles exhibited potent antimicrobial activity against oral pathogens, Streptococcus mutans, Staphylococcus aureus and Enterococcus faecalis, Candida albicans and can be developed as a novel medicine against pathogenic oral diseases. Abies webbiana extract mediated zinc oxide nanoparticles showed effective antimicrobial activity comparable to others.
 Conclusion: With increasing demand in advancements in diagnosis and treatment modalities, green synthesis of zinc oxide nanoparticles using A. webbiana which was found to have potent antimicrobial action has wider applications in dentistry. This formulation needs to be further purified to isolate the component in the extract that makes it effective to be used in large scale production for targeted drug delivery against a wide array of oral microbial infections.