Sclerotinia Sclerotiorum(White Mold): Cytotoxic, Mutagenic, and Antimalarial EffectsIn VivoandIn Vitro

Phenolic-rich extracts from toasted white and tannin sorghum flours have distinct profiles influencing their antioxidant, antiproliferative, anti-adhesive, anti-invasive, and antimalarial activities

Sorghum is a gluten-free cereal commonly used in foods, and its consumption has been associated with the prevention of human chronic conditions such as obesity and cancer, due to the presence of dietary fiber and phenolic compounds. This study aimed to evaluate, for the first time, the antiproliferative, antioxidant, anti-adhesion, anti-invasion, and antimalarial activities of phenolic extracts from toasted white and tannin sorghum flours to understand how different phenolic profiles contribute to sorghum biological activities. Water and 70 % ethanol/water (v/v), eco-friendly solvents, were used to obtain the phenolic extracts of toasted sorghum flours, and their phenolic profile was analyzed by UPLC-MSE. One hundred forty-five (145) phenolic compounds were identified, with 23 compounds common to all extracts. The solvent type affected the phenolic composition, with aqueous extract of both white sorghum (WSA) and tannin sorghum (TSA) containing mainly phenolic acids. White sorghum (WSE) and tannin sorghum (TSE) ethanolic extracts exhibited a higher abundance of flavonoids. WSE demonstrated the lowest IC50 on EA.hy926 (IC50 = 46.6 µg/mL) and A549 cancer cells (IC50 = 33.1 µg/mL), while TSE showed the lowest IC50 (IC50 = 70.8 µg/mL) on HCT-8 cells (human colon carcinoma). Aqueous extracts also demonstrated interesting results, similar to TSE, showing selectivity for cancer cells at higher IC50 concentrations. All sorghum extracts also reduced the adhesion and invasion of HCT-8 cells, suggesting antimetastatic potential. WSE, rich in phenolic acids and flavonoids, exhibited greater toxicity to both the W2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive) strains of Plasmodium falciparum (IC50 = 8 µg GAE/mL and 22.9 µg GAE/mL, respectively). These findings underscore the potential health benefits of toasted sorghum flours, suggesting diverse applications in the food industry as a functional ingredient or even as an antioxidant supplement. Moreover, it is suggested that, besides the phenolic concentration, the phenolic profile is important to understand the health benefits of sorghum flours.

Fluxapyroxad Resistance Mechanisms in Sclerotinia sclerotiorum

The necrotrophic pathogen Sclerotinia sclerotiorum has a global distribution and a wide host range, making it one of the most damaging and economically important of all plant pathogens. The current study found that fluxapyroxad, a typical succinate dehydrogenase inhibitor fungicide, had a strong inhibitory effect against S. sclerotiorum, with mean effective concentration for 50% inhibition (EC₅₀) values ranging from 0.021 to 0.095 µg/ml. Further investigation of five highly resistant S. sclerotiorum mutants, with EC₅₀ values of 12.37 to 31.36 µg/ml, found that fluxapyroxad resistance was accompanied by a certain cost to fitness. All of the mutants were found to have significantly (P < 0.05) reduced mycelial growth and altered sclerotia production in artificial culture, as well as reduced pathogenicity, compared with wild-type isolates, with one mutant completely losing the capacity to infect detached soybean leaves. Sequence analysis demonstrated that four of the mutants had point mutations leading to amino acid changes in the SsSdhB subunit of the fungicide target protein succinate dehydrogenase. In addition, two of the mutants were also found to have amino acid changes in the predicted sequence of their SsSdhD subunit, while the fifth mutant had no changes in any of its SsSdh sequences, indicating that an alternative mechanism might be responsible for the observed resistance in this mutant. No cross-resistance was found between fluxapyroxad and any of the other fungicides tested, including tebuconazole, prochloraz, dimethachlone, carbendazim, procymidone, pyraclostrobin, boscalid, fluazinam, fludioxonil, and cyprodinil, which indicates that fluxapyroxad has great potential as an alternative method of control for the Sclerotinia stem rot caused by S. sclerotiorum, and which could provide ongoing protection to the soybean fields of China.

First Report of Clonostachys rosea as a Mycoparasite on Sclerotinia sclerotiorum Causing Head Rot of Cabbage in India

Clonostachys rosea, an ascomycetous, omnipresent, cellulose-decaying soil fungus, has been reported to be a well-known mycoparasitic biological control agent. In this study, we isolated C. rosea, a mycoparasitic fungus for the first time in India from sclerotia of the notorious plant pathogen Sclerotinia sclerotiorum, causing head rot disease in cabbage. A total of five mycoparasitic fungi were isolated from the sclerotial bodies of S. sclerotiorum (TNAU-CR 01, 02, 03, 04 and 05). All the isolates were tested under morpho-molecular characterization. Among them, TNAU-CR 02 showed the greatest mycelial inhibition of 79.63% over the control. Similarly, the SEM imaging of effective C. rosea isolates indicated the presence of numerous conidia destroying the outer cortex layers of sclerotia. Metabolite fingerprinting of C. rosea TNAU-CR 02 identified 18 chemical compounds using GC-MS analysis. The crude antibiotics of C. rosea TNAU-CR 02 were verified for their antifungal activity against S. sclerotiorum and the results revealed 97.17% mycelial inhibition compared with the control. Similarly, foliar application of TNAU-CR 02 at 5 mL/litre on 30, 45 and 60 days after transplanting showed the lowest disease incidence of 15.1 PDI compared to the control. This discovery expands our understanding of the biology and the dissemination of C. rosea, providing a way for the exploitation of C. rosea against cabbage head rot pathogens.

In Vitro Efficacy of Extracts and Isolated Bioactive Compounds from Ascomycota Fungi in the Treatment of Colorectal Cancer: A Systematic Review

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Despite the advances and success of current treatments (e.g., chemotherapy), there are multiple serious side effects which require the development of new treatment strategies. In recent years, fungi have gained considerable attention as a source of extracts and bioactive compounds with antitumor capabilities because of their antimicrobial and antioxidant properties and even their anti-inflammatory and antiviral activities. In the present review, a systematic search of the existing literature in four electronic databases was carried out in which the antitumor activity against CRC cells of Ascomycota fungi extracts or compounds was tested. The systematical research in the four databases resulted in a total of 883 articles. After applying exclusion and inclusion criteria, a total of 75 articles were finally studied. The order Eurotiales was the most studied (46% of the articles), and the ethyl acetate extraction was the most used method (49% of the papers). Penicillium extracts and gliotoxin and acetylgliotoxin G bioactive compounds showed the highest cytotoxic activity. This review also focuses on the action mechanisms of the extracts and bioactive compounds of fungi against CRC, which were mediated by apoptosis induction and the arrest of the cell cycle, which induces a notable reduction in the CRC cell proliferation capacity, and by the reduction in cell migration that limits their ability to produce metastasis. Thus, the ability of fungi to induce the death of cancer cells through different mechanisms may be the basis for the development of new therapies that improve the current results, especially in the more advanced stages of the CCR.

Quantitative trait locus mapping and improved resistance to sclerotinia stem rot in a backbone parent of rapeseed (Brassica napus L.)

There are three main challenges to improving sclerotinia stem rot (SSR) resistance in rapeseed (Brassica napus L.). First, breeding materials such as the backbone parents have not been extensively investigated, making the findings of previous studies difficult to directly implement. Second, SSR resistance and flowering time (FT) loci are typically linked; thus, use of these loci requires sacrifice of the rapeseed growth period. Third, the SSR resistance loci in susceptible materials are often neglected, thereby reducing the richness of resistant resources. This study was conducted to investigate the stem resistance, disease index, and FT of a doubled haploid population consisting of 151 lines constructed from the backbone parent 19514A and conventional rapeseed cultivar ZY50 within multiple environments. Quantitative trait locus (QTL) mapping revealed 13 stem resistance QTLs, 9 disease index QTLs, and 20 FT QTLs. QTL meta-analysis showed that uqA04, uqC03.1, and uqC03.2 were repeatable SSR resistance QTLs derived from different parents but not affected by the FT. Based on these three QTLs, we proposed a strategy for improving the SSR resistance of 19514A and ZY50. This study improves the understanding of the resistance to rapeseed SSR and genetic basis of FT and demonstrates that SSR resistance QTLs can be mined from parents with a minimal resistance level difference, thereby supporting the application of backbone parents in related research and resistance improvement.

Transcriptome Analysis Reveals the Mechanism of dill Seed Essential oil Against Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a notorious fungal pathogen with a broad host range, including many important crops. A previous study showed dill seed essential oil (DSEO) could inhibit S sclerotiorum pathogenicity and protect canola production. However, the molecular basis of DSEO anti-fungal activity is still not well studied. To investigate the mechanism of DSEO anti-fungal activity, RNA-sequencing was employed to identify differentially expressed genes (DEGs) of S sclerotiorum in response to DSEO treatment. A total of 2470, 3218, and 3793 DEGs were identified in S sclerotiorum after being treated by DSEO for 0.5, 1, and 2 h, respectively. These genes that express changes in the early stage are more likely affected directly by DSEO. Gene Ontology (GO) analysis revealed that these genes were mainly related to transmembrane transport, cell membrane, ribosome biogenesis, and proteasome complex. DSEO treatment primarily affected the membrane part of the fungal cell, particularly the endoplasmic reticulum (ER) membrane at 0.5 and 1-hour treatment. In addition, a bunch of DEGs associated with the proteasome pathway was markedly enriched at 2 h of treatment. It is speculated that DSEO achieves antifungal effects by influencing these targets or pathways. The information obtained in this study expanded the understanding of the antifungal mechanism of DSEO and enriched the resources available for interpreting its mechanism at molecular level.

Sclerotinia Stem Rot Resistance in Rapeseed: Recent Progress and Future Prospects

Sclerotinia stem rot (SSR) of rapeseed (Brassica napus), caused by the soil-borne fungus Sclerotinia sclerotiorum, is one of the main diseases seriously affecting the yield and oil quality of infected rapeseed crops. The complexity of the inheritance of resistance and of the interaction mechanisms between rapeseed and S. sclerotiorum limits resistance gene identification and molecular breeding. In this review, the latest progress of research into resistance to SSR in B. napus is summarized from the following three directions: the pathogenesis mechanisms of S. sclerotiorum, the resistance mechanisms of B. napus toward S. sclerotiorum, and rapeseed breeding for resistance to SSR. This review aims to provide a theoretical basis and useful reference for analyzing the mechanism of the interaction between B. napus and S. sclerotiorum, searching for gene loci associated with the resistance response, and for achieving disease-resistance genetic manipulation and molecular design breeding in rapeseed.