Ergosterol from the soilborne fungus Ganoderma boninense

An In-Depth Study of Phytopathogenic Ganoderma: Pathogenicity, Advanced Detection Techniques, Control Strategies, and Sustainable Management

Phytopathogenic Ganoderma species pose a significant threat to global plant health, resulting in estimated annual economic losses exceeding USD (US Dollars) 68 billion in the agriculture and forestry sectors worldwide. To combat this pervasive menace effectively, a comprehensive understanding of the biology, ecology, and plant infection mechanisms of these pathogens is imperative. This comprehensive review critically examines various aspects of Ganoderma spp., including their intricate life cycle, their disease mechanisms, and the multifaceted environmental factors influencing their spread. Recent studies have quantified the economic impact of Ganoderma infections, revealing staggering yield losses ranging from 20% to 80% across various crops. In particular, oil palm plantations suffer devastating losses, with an estimated annual reduction in yield exceeding 50 million metric tons. Moreover, this review elucidates the dynamic interactions between Ganoderma and host plants, delineating the pathogen's colonization strategies and its elicitation of intricate plant defense responses. This comprehensive analysis underscores the imperative for adopting an integrated approach to Ganoderma disease management. By synergistically harnessing cultural practices, biological control, and chemical treatments and by deploying resistant plant varieties, substantial strides can be made in mitigating Ganoderma infestations. Furthermore, a collaborative effort involving scientists, breeders, and growers is paramount in the development and implementation of sustainable strategies against this pernicious plant pathogen. Through rigorous scientific inquiry and evidence-based practices, we can strive towards safeguarding global plant health and mitigating the dire economic consequences inflicted by Ganoderma infections.

A gene cluster encoding a nonribosomal peptide synthetase-like enzyme catalyzes γ-aromatic butenolides

Sea cucumber-derived fungi have attracted much attention due to their capacity to produce an incredible variety of secondary metabolites. Genome-wide information on Aspergillus micronesiensis H39 obtained using third-generation sequencing technology (PacBio-SMRT) showed that the strain contains nonribosomal peptide synthetase (NRPS)-like gene clusters, which aroused our interest in mining its secondary metabolites. 11 known compounds (1-11), including two γ-aromatic butenolides (γ-AB) and five cytochalasans, were isolated from A. micronesiensis H39. The structures of the compounds were determined by NMR and ESIMS, and comparison with those reported in the literature. From the perspective of biogenetic origins, the γ-butyrolactone core of compounds 1 and 2 was assembled by NRPS-like enzyme. All of the obtained compounds showed no inhibitory activity against drug-resistant bacteria and fungi, as well as compounds 1 and 2 had no anti-angiogenic activity against zebrafish.

Mushrooms as Potential Sources of Active Metabolites and Medicines

Background

Mushrooms exist as an integral and vital component of the ecosystem and are very precious fungi. Mushrooms have been traditionally used in herbal medicines for many centuries.

Scope and Approach

There are a variety of medicinal mushrooms mentioned in the current work such as Agaricus, Amanita, Calocybe, Cantharellus, Cordyceps, Coprinus, Cortinarius, Ganoderma, Grifola, Huitlacoche, Hydnum, Lentinus, Morchella, Pleurotus, Rigidoporus, Tremella, Trametes sp., etc., which play a vital role in various diseases because of several metabolic components and nutritional values. Medicinal mushrooms can be identified morphologically on the basis of their size, color (white, black, yellow, brown, cream, pink and purple-brown, etc.), chemical reactions, consistency of the stalk and cap, mode of attachment of the gills to the stalk, and spore color and mass, and further identified at a molecular level by Internal Transcribed Spacer (ITS) regions of gene sequencing. There are also other methods that have recently begun to be used for the identification of mushrooms such as high-pressure liquid chromatography (HPLC), nuclear magnetic resonance spectroscopy (NMR), microscopy, thin-layer chromatography (TLC), DNA sequencing, gas chromatography-mass spectrometry (GC-MS), chemical finger printing, ultra-performance liquid chromatography (UPLC), fourier transform infrared spectroscopy (FTIR), liquid chromatography quadrupole time-of-flight mass spectrometry (LCMS-TOF) and high-performance thin-layer chromatography (HPTLC). Lately, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technique is also used for the identification of fungi.

Key Finding and Conclusion

Medicinal mushrooms possess various biological activities like anti-oxidant, anti-cancer, anti-inflammatory, anti-aging, anti-tumor, anti-viral, anti-parasitic, anti-microbial, hepatoprotective, anti-HIV, anti-diabetic, and many others that will be mentioned in this article. This manuscript will provide future direction, action mechanisms, applications, and the recent collective information of medicinal mushrooms. In addition to many unknown metabolites and patented active metabolites are also included.

Antibacterial activities of the chemical constituents of Schizophyllum commune MST7-3 collected from coal area

Two fusidane-type active compounds (6 and 7) and five new ones (1-5), along with other nine known compounds (8-16) were isolated from the metabolites of Schizophyllum commune MST7-3. Their structures were elucidated on the basis of spectroscopic analysis. The absolute configurations of compounds 2 and 3 were established by Mosher's method and optical rotation. Compounds 6 and 7 showed significant antibacterial activities against Stenotrophomonas maltophilia with MIC values of 4 μg/mL and 16 μg/mL, respectively.

Isolation and Identification of Tyrosinase Inhibitors from Marine Algae Enteromorpha sp

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The extract of marine green algae Enteromorpha sp. was evaluated in vitro for inhibitory activity against mushroom tyrosinase enzyme. The principle active agents i.e. coumarin; 4-hydroxycoumarin (1) and two sterols; ergosta-5,7,22-trien-3β-ol (2) & ergosterol peroxide (3) were isolated for the first time, from a crude methanol extract of Enteromorpha sp. showing anti-tyrosinase activity. Their structures were elucidated by IR, extensive NMR spectroscopy, LC-ESI-MS, Single crystal X-ray diffraction techniques. Thus, Enteromorpha sp. can be an alternative edible anti-tyrosinase agent.

Relationship between Ganoderma Ergosterol Concentration and Basal Stem Rot Disease Progress on Elaeis guineensis

Basal stem rot (BSR) is a devastating disease to Malaysian oil palm. Current techniques employed for BSR disease detection on oil palm are laborious, time consuming, costly, and subjected to accuracy limitations. An ergosterol detection method was developed, whereby it correlated well with the degree of infection in oil palm. This current study was designed to study the relationship between Ganoderma biomass, ergosterol concentration, BSR disease progress and to validate the efficiency of microwave assisted extraction (MAE) method for extraction of ergosterol compound. In addition, testing on the sensitivity of thin layer chromatography (TLC) analysis for detection of ergosterol was also the aim of this study. The optimised procedure involved extracting a small amount of Ganoderma-infected oil palm root tissues suspended in low volumes of solvent followed by irradiation in a conventional microwave oven at 70°C and medium high power for 30 s, resulting in simultaneous extraction and saponification. Based on the results obtained, MAE method may be effective in extracting low to high yields of ergosterol from infected oil palm roots demonstrating disease scale 2, 3 and 4. Positive relationship was observed between ergosterol content and inoculation period starting day 3 in the inoculated oil palm seedlings and hour 6 in germinated seeds. TLC analysis demonstrated a good correlation with high performance liquid chromatography (HPLC) quantification. Therefore, a semi-quantitative TLC analysis may be applied for handling a large amount of samples during onset field survey.

Transciptome profiling at early infection of Elaeis guineensis by Ganoderma boninense provides novel insights on fungal transition from biotrophic to necrotrophic phase

BACKGROUND

Basal stem rot (BSR) caused by hemibiotroph Ganoderma boninense is a devastating disease resulting in a major loss to the oil palm industry. Since there is no physical symptom in oil palm at the early stage of G. boninense infection, characterisation of molecular defense responses in oil palm during early interaction with the fungus is of the utmost importance. Oil palm (Elaeis guineensis) seedlings were artificially infected with G. boninense inoculums and root samples were obtained following a time-course of 0, 3, 7, and 11 days-post-inoculation (d.p.i) for RNA sequencing (RNA-seq) and identification of differentially expressed genes (DEGs).

RESULTS

The host counter-attack was evidenced based on fungal hyphae and Ganoderma DNA observed at 3 d.p.i which became significantly reduced at 7 and 11 d.p.i. DEGs revealed upregulation of multifaceted defense related genes such as PR-protein (EgPR-1), protease inhibitor (EgBGIA), PRR protein (EgLYK3) chitinase (EgCht) and expansin (EgEXPB18) at 3 d.p.i and 7 d.p.i which dropped at 11 d.p.i. Later stage involved highly expressed transcription factors EgERF113 and EgMYC2 as potential regulators of necrotrophic defense at 11 d.p.i. The reactive oxygen species (ROS) elicitor: peroxidase (EgPER) and NADPH oxidase (EgRBOH) were upregulated and maintained throughout the treatment period. Growth and nutrient distribution were probably compromised through suppression of auxin signalling and iron uptake genes.

CONCLUSIONS

Based on the analysis of oil palm gene expression, it was deduced that the biotrophic phase of Ganoderma had possibly occurred at the early phase (3 until 7 d.p.i) before being challenged by the fungus via switching its lifestyle into the necrotrophic phase at later stage (11 d.p.i) and finally succumbed the host. Together, the findings suggest the dynamic defense process in oil palm and potential candidates that can serve as phase-specific biomarkers at the early stages of oil palm-G. boninense interaction.

Ganoderma: A Cancer Immunotherapy Review

Ganoderma is a significant source of natural fungal medicines and has been used for the treatment of various diseases for many years. However, the use of Ganoderma in cancer immunotherapy is poorly elucidated. In this study, we have analyzed 2,398 English-language papers and 6,968 Chinese-language papers published between 1987 and 2017 by using bibliometrics. A steady growth in the number of publications was observed before 2004, followed by an exponential increase between 2004 and 2017. The most common category for publications about Ganoderma was "Pharmacology & Pharmacy," in which immunomodulation (25.60%) and cancer treatment (21.40%) were the most popular subcategories. Moreover, we have provided an overview of the bioactive components and combinatorial immunomodulatory effects for the use of Ganoderma in the treatment of cancer, including the major pathways of immune cells. Immunomodulatory protein and polysaccharides are the key bioactive factors responsible for cancer immunotherapy, and the NF-κB and MAPK pathways are the most comprehensively investigated major pathways. Our results indicate that Ganoderma has a broad-spectrum application for the treatment of cancer through the regulation of the immune system. This review provides guidance for future research into the role of Ganoderma in cancer immunotherapy.

Differences in carbon source utilisation by orchid mycorrhizal fungi from common and endangered species of Caladenia (Orchidaceae)

Terrestrial orchids depend on orchid mycorrhizal fungi (OMF) as symbionts for their survival, growth and nutrition. The ability of OMF from endangered orchid species to compete for available resources with OMF from common species may affect the distribution, abundance and therefore conservation status of their orchid hosts. Eight symbiotically effective OMF from endangered and more common Caladenia species were tested for their ability to utilise complex insoluble and simple soluble carbon sources produced during litter degradation by growth with different carbon sources in liquid medium to measure the degree of OMF variation with host conservation status or taxonomy. On simple carbon sources, fungal growth was assessed by biomass. On insoluble substrates, ergosterol content was assessed using ultra-performance liquid chromatography (UPLC). The OMF grew on all natural materials and complex carbon sources, but produced the greatest biomass on xylan and starch and the least on bark and chitin. On simple carbon sources, the greatest OMF biomass was measured on most hexoses and disaccharides and the least on galactose and arabinose. Only some OMF used sucrose, the most common sugar in green plants, with possible implications for symbiosis. OMF from common orchids produced more ergosterol and biomass than those from endangered orchids in the Dilatata and Reticulata groups but not in the Patersonii and Finger orchids. This suggests that differences in carbon source utilisation may contribute to differences in the distribution of some orchids, if these differences are retained on site.

Understanding colonization and proliferation potential of endophytes and pathogen in planta via plating, polymerase chain reaction and ergosterol assay

This study aimed to establish the colonization behavior and proliferation potential of three endophytes and one pathogen Ganoderma boninense (Gb) introduced into oil palm ramets (host model). The endophytes selected were Diaporthe phaseolorum (WAA02), Trichoderma asperellum (T2), and Penicillium citrinum (BTF08). Ramets were first inoculated with 100 mL of fungal cells (106 cfu mL-1) via soil drenching. For the next 7 days, ramets were sampled and subjected to three different assays to detect and identify fungal colonization, and establish their proliferation potential in planta. Plate assay revealed the presence of endophytes in root, stem and leaf tissues within 7 days after inoculation. Polymerase Chain Reaction (PCR) detected and identified the isolates from the plant tissues. The ergosterol assay (via high performance liquid chromatography, HPLC) confirmed the presence of endophytes and Gb in planta. The increase in ergosterol levels throughout 49 days was however insignificant, suggesting that proliferation may be absent or may occur very slowly in planta. This study strongly suggests that the selected endophytes could colonize the host upon inoculation, but proliferation occurs at a slower rate, which may subsequently influence the biocontrol expression of endophytes against the pathogen.

Advances in the Interpretation of Tomographic Images as an Early Detection Method of Oil Palm Affected by Basal Stem Rot in Colombia

Basal stem rot, one of the most important diseases of oil palm in Southeast Asia, has also been identified in Colombia. The increase in disease incidence in the last decade has attracted the attention of producers and researchers. In the search for a procedure that allows for the early identification of diseased palm, Cenipalma evaluated the use of electrical impedance tomography to identify the different stages of development of basal stem rot. The tomograms were compared with transversal sections of healthy and diseased oil palm trees. Following Cenipalma's preliminary studies on early diagnosis of basal stem rot with tomography, the present study improved upon the technique by analyzing the tomograms of 209 diseased palm trees (confirmed by symptomatology), 346 asymptomatic palm trees, and 132 healthy palm trees. The minimum and maximum electric impedance values as well as the ratio between these values was recorded. The range of 1 to 95 Ω was used to represent the internal damage. The ratios averaged 5.1 for diseased, 1.9 for asymptomatic, and 1.5 for healthy palm trees. With the range and the ratio criteria established, it was possible to identify the disease in 100% of asymptomatic sampled palm trees. This study demonstrated that electrical impedance tomography is a powerful tool for early detection of basal stem rot, which can be used to establish an early disease management program.