Mycelial Growth Research Articles

Application and Evaluation of the Antifungal Activities of Glandular Trichome Secretions from Air/Sun-Cured Tobacco Germplasms against Botrytis cinerea.

The secretions of the glandular trichomes of tobacco leaves and flowers contain abundant secondary metabolites of different compounds, such as cebradanes, labdanes, and saccharide esters. These secondary metabolites have shown interesting biological properties, such as antimicrobial, insecticidal, and antioxidant activity. In this study, 81 air/sun-cured tobacco germplasms were used as experimental materials. Quantitative and qualitative analyses of the glandular secretion components were conducted using ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF MS) and gas chromatography-mass spectrometry (GC-MS). The ethanol extracts of glandular trichomes from tobacco leaves and flowers were evaluated for antifungal activity against the fungus Botrytis cinerea using the mycelial growth rate method. Orthogonal Partial Least Squares (OPLS) analysis was then performed to determine the relationship between the trichome secretion components and their anti-fungal activity. The results showed significant differences among the antifungal activities of the tested ethanol extracts of tobacco glandular trichomes. The inhibition rates of the upper leaves and flower extracts against B. cinerea were significantly higher than those of the middle and lower leaves, and 59 germplasms (73.75% of the tested resources) showed antifungal rates higher than 50%, with four germplasms achieving a 95% antifungal rate at the same fresh weight concentration (10 mg/mL). The OPLS analysis revealed that the antifungal activity was primarily associated with alpha-cembratriene-diol (α-CBT-diol (Peak7)) and beta-cembratriene-diol (β-CBT-diol (Peak8)), followed by sucrose esters III (SE(III)) and cembratriene-diol oxide. These findings help identify excellent tobacco germplasms for the development and utilization of botanical pesticides against fungi and provide a theoretical reference for the multipurpose utilization of tobacco germplasms.

Study on the Identification, Biological Characteristics, and Fungicide Sensitivity of the Causal Agent of Strawberry Red Core Root Rot

Strawberry red core root rot disease affects the growth and yield of strawberry (Fragaria ananassa Duch), which leads to economic losses in China. The study employed a tissue separation method to isolate and identify the causal agent responsible for strawberry red core root rot. This was achieved by the observation of its morphological characteristics, sequencing analyses, and pathogenicity tests. The sensitivity of five chemical fungicides against the two species of Fusarium was determined using the mycelial growth rate method, and the biological characteristics of the two species were examined. The pathogens were identified as Fusarium solani and Fusarium oxysporum. The optimal conditions for the mycelial growth of F. solani and F. oxysporum were determined to be potato sucrose agar at 25 °C and pH 6, and potato dextrose agar at 30 °C and pH 8, respectively, with a 24:24 light cycle. The most suitable carbon and nitrogen sources for the mycelial growth of F. solani were sucrose and sodium nitrate (NaNO3), while for F. oxysporum, they were glucose and peptone. A fungicide sensitivity test indicated that Prochloraz had a good inhibitory effect on the growth of F. solani and F. oxysporum with EC50 values of 0.088 mg L−1 and 0.162 mg. The growth inhibition effect of Azoxystrobin to F. solani and Carbendazim to F. oxysporum was not obvious. This study provides a theoretical basis for further research on strawberry red core root disease and its prevention.

Curse or blessing: Growth- and laccase-modulating properties of polyphenols and their oxidized derivatives on Botrytis cinerea

Infection of grapevines with the grey mold pathogen Botrytis cinerea results in severe problems for winemakers worldwide. Browning of wine is caused by the laccase-mediated oxidation of polyphenols. In the last decades, Botrytis management has become increasingly difficult due to the rising number of resistances and the genetic variety of Botrytis strains. During the search for sustainable fungicides, polyphenols showed great potential to inhibit fungal growth. The present study revealed two important aspects regarding the effects of grape-specific polyphenols and their polymerized oxidation products on Botrytis wild strains. On the one hand, laccase-mediated oxidized polyphenols, which resemble the products found in infected grapes, showed the same potential for inhibition of growth and laccase activity, but differed from their native forms. On the other hand, the impact of phenolic compounds on mycelial growth is not correlated to the effect on laccase activity. Instead, mycelial growth and relative specific laccase activity appear to be modulated independently. All phenolic compounds showed not only inhibitory but also inductive effects on fungal growth and/or laccase activity, an observation which is reported for the first time. The simultaneous inhibition of growth and laccase activity demonstrated may serve as a basis for the development of a natural botryticide. Yet, the results showed considerable differences between genetically distinguishable strains, impeding the use of a specific phenolic compound against the genetic variety of wild strains. The present findings might have important implications for future understanding of Botrytis cinerea infections and sustainable Botrytis management including the role of polyphenols.

The Effect of Broccoli Glucosinolates Hydrolysis Products on Botrytis cinerea: A Potential New Antifungal Agent.

The present study investigates the interactions between eight glucosinolate hydrolysis products (GHPs) sourced from broccoli by-products and the detoxifying enzymes of Botrytis cinerea, namely eburicol 14-alpha-demethylase (CYP51) and glutathione-S-transferase (GST), through in silico analysis. Additionally, in vitro assays were conducted to explore the impact of these compounds on fungal growth. Our findings reveal that GHPs exhibit greater efficacy in inhibiting conidia germination compared to mycelium growth. Furthermore, the results demonstrate the antifungal activity of glucosinolate hydrolysis products derived from various parts of the broccoli plant, including inflorescences, leaves, and stems, against B. cinerea. Importantly, the results suggest that these hydrolysis products interact with the detoxifying enzymes of the fungus, potentially contributing to their antifungal properties. Extracts rich in GHPs, particularly iberin and indole-GHPs, derived from broccoli by-products emerge as promising candidates for biofungicidal applications, offering a sustainable and novel approach to plant protection by harnessing bioactive compounds from agricultural residues.

Roles of α-1,3-glucosyltransferase in growth and polysaccharides biosynthesis of Ganoderma lucidum

Ganoderma lucidum polysaccharides are valuable natural compounds possessing significant biological activity, with glycosyltransferases playing a crucial role in their biosynthesis. Although the function of β-1,3-glucosyltransferase in polysaccharides production is well understood, the role of α-1,3-glucosyltransferase in edible fungi remains unclear. In this study, over-expression of the α-1,3-glucosyltransferase gene in G. lucidum (glagt) was found to suppress the growth, with the maximum biomass and mycelial growth rate decreasing by 21.78 % and 79.61 %, respectively, a behavior distinct from β-1,3-glucosyltransferase. The fungal pellet diameter decreased by 38 % and the cell-wall thickness by 32.44 %, whereas intracellular and extracellular polysaccharides production increased by 27.58 % and 66.08 %, respectively. In the transcription level, overexpressing the glagt gene i) downregulated the citrate synthase and isocitrate dehydrogenase gene in the TCA cycle, disrupting energy metabolism and fungal growth; ii) upregulated key enzymes involved in UDP-glucose synthesis and glycosyltransferases (gl24465, gl24971, and gl22535); and iii) universally increased the transcriptional level of glucosidases gl21451, gl30087, and gl24581 by 22 %–397 %, contributing to cell-wall thinning to facilitate polysaccharides export. Conversely, the glagt gene downregulation promoted G. lucidum growth and decreased polysaccharides production. The results elucidate the roles of GLAGT and are expected to inspire in-depth exploration of polysaccharides biosynthesis pathways.

Biocontrol Mechanisms of Three Plant Essential Oils Against Phytophthora infestans Causing Potato Late Blight.

Late blight, caused by the notorious pathogen Phytophthora infestans, poses a significant threat to potato (Solanum tuberosum) crops worldwide, impacting their quality as well as yield. Here, we aimed to investigate the potential use of cinnamaldehyde, carvacrol, and eugenol as control agents against P. infestans and to elucidate their underlying mechanisms of action. To determine the pathogen-inhibiting concentrations of these three plant essential oils (PEOs), a comprehensive evaluation of their effects using gradient dilution, mycelial growth rate, and spore germination methods was carried out. Cinnamaldehyde, carvacrol, and eugenol were capable of significantly inhibiting P. infestans by hindering its mycelial radial growth, zoospore release, and sporangium germination; the median effective inhibitory concentration of the three PEOs was 23.87, 8.66, and 89.65 μl/liter, respectively. Scanning electron microscopy revealed that PEOs caused the irreversible deformation of P. infestans, resulting in hyphal shrinkage, distortion, and breakage. Moreover, propidium iodide staining and extracellular conductivity measurements demonstrated that all three PEOs significantly impaired the integrity and permeability of the pathogen's cell membrane in a time- and dose-dependent manner. In vivo experiments confirmed the dose-dependent efficacy of PEOs in reducing the lesion diameter of potato late blight. Altogether, these findings provide valuable insight into the antifungal mechanisms of PEOs vis-à-vis late blight-causing P. infestans. By utilizing the inherent capabilities of these natural compounds, we could effectively limit the harmful impacts of late blight on potato crops, thereby enhancing agricultural practices and ensuring the resilience of global potato food production.

Functional analysis of all succinate dehydrogenase subunits in Fusarium fujikuroi

Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), contains five succinate dehydrogenase (Sdh) subunits: FfSdhA, FfSdhB, FfSdhC1, FfSdhC2, and FfSdhD. However, the role of these subunits in regulating sensitivity to succinate dehydrogenase inhibitors (SDHIs) is largely unknown. Here, we conducted targeted gene disruption and phenotypic assays for all Sdh subunits and found that the deletion mutants of FfSdhA, FfSdhB, and FfSdhD exhibited severe defects in hyphal growth, conidiation, virulence, and sensitivity to CaCl2 and oxidative stresses. To a lesser extent, the mycelial growth rate and conidial production of ΔFfSdhC1 were also decreased as compared to those of the wild-type strain JS16. In addition, fungicide sensitivity assays showed that deletion of FfSdhA, B, C1, or D led to decreased sensitivity to all SDHIs tested. Unexpectedly, we were unable to obtain a FfSdhC1 + C2 double mutant and further found significant up-regulation of FfSdhC2 in ∆FfSdhC1, indicating that FfSdhC1 and -C2 might be essential for fungal growth although the FfSdhC2 deletion mutant was indistinguishable from the wild-type strain. These findings provide useful information for enhancing our understanding of the biological functions of the Sdh subunits in pathogenic fungi.

Biocontrol efficacy of Pseudomonas mediterranea PVCT 3C against Plenodomus tracheiphilus: In vitro and in planta mechanisms at early disease stages

In this study, we investigated the biocontrol activity of the P. mediterranea strain PVCT 3C against Mal secco, a severe disease of citrus caused by the vascular fungus Plenodomus tracheiphilus. In vitro, bacterial diffusible compounds, volatile organic compounds and culture filtrates produced by PVCT 3C reduced the mycelial growth and conidial germination of P. tracheiphilus, also affecting the mycelial pigmentation. The application of bacterial suspensions by leaf-spraying before the inoculation with the pathogen on plants of the highly susceptible species sour orange and lemon led to an overall reduction in incidence and disease index, above all during the early disease stage. PVCT 3C genome was subjected to whole-genome shotgun sequencing to study the molecular mechanisms of action of this strain. In silico annotation of biosynthetic gene clusters for secondary metabolites revealed the presence of numerous clusters encoding antimicrobial compounds (e.g. cyclic lipopeptides, hydrogen cyanide, siderophores) and candidate novel products. During the asymptomatic disease phase (seven days post-inoculation), bacterial treatments interfered with the expression of different fungal genes, as assessed with an NGS and de novo assembly RNA-seq approach. These results suggest that P. mediterranea PVCT 3C or its secondary metabolites may offer a potential effective and sustainable alternative to contain P. tracheiphilus infections via integrated management.

Fusarium solani associated with Cedrela odorata and Swietenia macrophylla and their sensitivity to conventional fungicides

Background / Objective. In the state of Yucatan, Mexico, 10 million forest plants were produced in the last five years for various conservation and restoration actions. The main limitations in the production of these plants in nursery are disease induced by the genus Fusarium spp., that cause stem and root rots and plant production losses of up to 50%. The objective of the work was to identify the causal agent associated with stem and root rot and necrosis of cedar (Cedrela odorata) and mahogany (Swietenia macrophylla) and their in vitro sensitivity to conventional fungicides. Materials and Methods. C. odorata and S. macrophylla plants were collected at three and six weeks of germination, respectively, with symptoms of necrosis and rot indicated; from where five fungal isolates were obtained and morphologically and molecularly identified. The Minimum Inhibitory Concentration (MIC) of spores and the Minimum Lethal Concentration (MLC) of six conventional fungicides of recurrent application in the region (Prochloraz, Carbendazim, Benomyl, Fosetyl Al, Captan and Mancozeb) were determined in vitro by the microdilution method and validate their effectiveness and viability in the management of this problematic. Results. The morphology and molecular sequences of the isolates were similar to the reported for Fusarium solani. The MIC of F. solani spores for Prochloraz, Carbendazim, Benomyl, Captan and Mancozeb were 2.44. 11.38, 14.06, 7.81 and 7.81 ppm, respectively; Fosetyl Al, did not inhibit spore germination normal mycelial growth of the fungus was observed at the concentration evaluated. Conclusion. Prochloraz and Mancozeb had the lowest MLC with 2.44 and 7.81 ppm, respectively.

Evaluation of Different Botanicals Against Sclerotium rolfsii Causing Collar Rot Disease of Lentil

Lentil (Lens culinaris Medik.) is an important pulse crop in semiarid regions of Iran, India, Turkey and Canada and originated in the fertile crescent of the Near East and dates back to the beginning of agriculture itself. Lentil suffer from attack of number seed borne diseases such as vascular wilt, collar rot, root rot, stem rot, rust, powdery mildew and downy mildew, which are caused by Fusarium oxysporum f.sp. lentis, Sclerotium rolfsii, Rhizoctonia solani, Uromycis fabae, Erysiphe polygoni and Peronospora lentis, respectively. Among the diseases, foot and root rot of lentil caused by Sclerotium rolfsii are common and the most severe disease. The fungi can attack the crop at any stage from seedling to flowering stage and are comparatively more destructive at the seedling stage. The effect of phyto extracts of nine plant species were tested in vitro by poisoned food technique to know their inhibitory effect on the growth of Sclerotium rolfsii. Significantly minimum mycelium growth was recorded in Curcuma longa (39.25 mm) while maximum mycelium growth was observed in Ricinus communis (90.00 mm).

ACTION OF Trichoderma asperellum AND BIOACTIVE METABOLITES ON Fusarium spp., PATHOGENS OF Carya illinoinensis

The cultivation of pecan tree [Carya illinoinensis (Wangenh.) K. Koch.] is expanding in Rio Grande do Sul state and, with that, there has been an increase in the disease reports. Among the diseases identified, there is a root rot caused by Fusarium spp. The control of phytopathogenic fungi present in the soil is difficult to obtain, and the control through antagonists such as Trichoderma spp. is a viable way of management. Thus, the objective of this work was to analyze different forms of action of Trichoderma asperellum in the control of Fusarium spp. The antagonistic action was evaluated by paring cultures, presence of volatile and non-volatile metabolites. The mycelial growth inhibition in the culture pairing ranged from 10.38% to 43.17%, while for volatile metabolites protection was lower, reaching values of a maximum of 14.54%. As for the non-volatile metabolites, a percentage of inhibition varied from zero for some treatments to 44.99% in the control of Fusarium graminearum. T. asperellum inhibited the growth of Fusarium spp. through different studied modes of action.

Functional Characterization of the Histone Acetyltransferase FcElp3 in Lotus Rhizome Rot-Causing Fungus Fusarium commune.

Fusarium commune is the main pathogen of lotus rhizome rot, which causes the wilt of many plants. Histone acetyltransferase plays a critical part in the growth and virulence of fungi. In the present study, we identified an FcElp3 in F. commune homologous to histone acetyltransferase Elp3. We further constructed a mutant strain of F. commune to determine the function of FcElp3 in fungal growth and pathogenicity. The results showed that the deletion of FcElp3 resulted in reduced mycelial growth and sporulation. Compared with the wild type, the ΔFcElp3 strain showed more tolerance to osmotic stress and cell wall stress responses but was highly sensitive to oxidative stress. The subcellular localization results indicated that FcElp3 was distributed in both the cytoplasm and nucleus. Western blotting showed that FcElp3 was important for acetylation of H3K14 and H4K8. RNA sequencing analysis showed significant transcriptional changes in the ΔFcElp3 mutant, with 3,098 genes upregulated and 5,770 genes downregulated. Peroxisome was the most significantly enriched metabolic pathway for downregulated genes. This led to a significant decrease in the expression of the core transcription factor Fcap1 involved in the oxidative stress response. Pathogenicity tests revealed that the ΔFcElp3 mutant's pathogenicity on lotus was significantly decreased. Together, these findings clearly demonstrated that FcElp3 was involved in fungal growth, development, stress response, and pathogenicity via the direct regulation of multiple target genes.

Postharvest biocontrol ability and involved mechanism of volatile organic compounds from Serratia nematodiphila BC-SKRU-1 against Penicillium digitatum tangerine fruit

Volatile organic compounds (VOCs) emitted by microorganisms offer a promising strategy for managing green mold disease in citrus fruits caused by Penicillium digitatum. This study evaluated the biocontrol efficacy of VOCs produced by Serratia nematodiphila BC-SKRU-1 (BC-SKRU-1 VOCs) against green mold in postharvest tangerine fruits, targeting P. digitatum NKP4321. Our findings demonstrated that BC-SKRU-1 VOCs exhibited a broad spectrum of activity against seven plant pathogens, with the highest efficacy observed against NKP4321 (68.21%). A concentration of 106 CFU mL−1 for VOC production by BC-SKRU-1 completely inhibited the mycelial growth of NKP4321, whereas a concentration of 107 CFU mL−1 was required to fully inhibit spore germination. The application of four plates of BC-SKRU-1 VOCs at 108 CFU mL−1 significantly reduced the severity of green mold disease, with optimal biocontrol achieved through continuous fumigation during storage. Notably, 2-nonanol, identified as the predominant component among the 20 VOCs using HS-SPME/GC-MS, exhibited superior antifungal activity both in vitro and in vivo. It effectively decreased ergosterol production and disrupted plasma membrane integrity in NKP4321 cells. Furthermore, 2-nonanol altered the cellular content of non-enzymatic antioxidants (e.g., GSH, GSSG) and enzymatic antioxidants (e.g., CAT, SOD), elucidating its comprehensive antifungal mechanism. These findings highlight the potential of BC-SKRU-1 VOCs, particularly 2-nonanol, as effective biocontrol agents for enhancing postharvest fruit preservation by combating fungal pathogens.

Screening of Castor Germplasm and Efficacy Studies of Bioagents and Fungicides Against Botryotinia ricini (Godfrey) Whetzel

Castor is an important non-edible oilseed crop having exceptional oil characteristics for the chemical industry. The crop hosts several diseases, among them gray mold is the most destructive one hindering its productivity. This article presents a study assessing the resistance of different germplasm lines screened against Botrytis ricini under artificial conditions. It also examines the effect of various fungicides on B. ricini isolates, which were obtained from infected Ricinus communis (castor oil plant) using standard tissue isolation techniques. The fungus was isolated from infected Castor raceme by standard tissue isolation technique and its pathogenicity was established by proving Koch’s postulates. Out of 47 germplasm lines screened, TSIL-19 showed resistance response to gray mold under both detached spike and capsule method. Under in vitro assessment, Trichoderma viride (86.11 %) and Pseudomonas fluorescens (71.48 %) bio agents exhibited maximum mycelial growth inhibition of the pathogen. Among the seven combination fungicides evaluated, Fenamidone 10% + Mancozeb 50% WG recorded highest mycelial growth inhibition (100%) of B. ricini.

Morpho-Molecular and Management of Pomegranate (Punica granatum L.) Wilt Caused by Ceratocystis fimbriata Ellis and Halst

Pomegranate wilt poses a significant threat to pomegranate production, holding considerable economic importance in the cultivated regions of pomegranates. The study investigated the wilt in pomegranate cultivation, revealing characteristic symptoms including yellowing and/or wilting of the leaves on a single branch usually in the upper crown and senescence. Brown discoloration was observed in the root, stem and branches of severely affected plants. The cross-sectioned root and stem portions of the wilted plants showed only the presence of brown discolorations in the vascular regions. The wilt incidence in Karnataka ranging from 1.14 to 62.06 Percent. PCR analysis and 18S rDNA region was sequenced, it has been confirmed C. fimbriata as the causal organism for pomegranate wilt and Phylogenetic analyses placed the pomegranate isolates among members of the LAC of the C. fimbriata complex; specifically, to populations that appear to be native to eastern and northern South America. Optimal growth of the pathogen was observed at 30 °C with pH 7.0 and best media for culturing C. fimbriata is Potato dextrose agar and Potato carrot agar, in vitro evaluation of fungicides showed propiconazole and mancozeb highest inhibiting mycelial growth. Trichoderma viride (Tv-3) and Bacillus subtilis emerged as the most effective bio-agent, while pongamia leaf extract exhibited maximum fungal growth inhibition. These can be used for the management of wilt disease.

Development of an RNA Nanostructure for Effective Botrytis cinerea Control through Spray-Induced Gene Silencing without an Extra Nanocarrier.

Spray-induced gene silencing represents an eco-friendly approach for crop protection through the use of double-stranded RNA (dsRNA) to activate the RNA interference (RNAi) pathway, thereby silencing crucial genes in pathogens. The major challenges associated with dsRNA are its limited stability and poor cellular uptake, necessitating repeated applications for effective crop protection. In this study, RNA nanoparticles (NPs) were proposed as effectors in plants and pathogens by inducing the RNAi pathway and silencing gene expression. RNA structural motifs, such as hairpin-loop, kissing-loop, and tetra-U motifs, were used to link multiple siRNAs into a long, single-stranded RNA (lssRNA). The lssRNA, synthesized in Escherichia coli, self-assembled into stable RNA nanostructures via local base pairing. Comparative analyses between dsRNA and RNA NPs revealed that the latter displayed superior efficacy in inhibiting spore germination and mycelial growth of Botrytis cinerea. Moreover, RNA NPs had a more robust protective effect on plants against B. cinerea than did dsRNA. In addition, RNA squares are processed into expected siRNA in plants, thereby inhibiting the expression of the target gene. These findings suggest the potential of RNA NPs for use in plant disease control by providing a more efficient and specific alternative to dsRNA without requiring nanocarriers.

Antifungal and Allelopathic Effects of Essential Oil from Calyptranthes concinna DC. Dried Leaves and of Its Major Constituent Elemicin

Essential oils (EOs) are natural products widely used in sustainable agrochemistry, not only because they are biodegradable and safe but also because they are regarded as alternatives to chemical fungicides against fungal species that attack crops. Allelopathy, another field of study, falls within the most recent and sustainable strategies applied to weed suppression to replace synthetic herbicides. Therefore, this study reports the chemical composition and allelopathic and antifungal effects of the EOs extracted from Calyptranthes concinna dried leaves (Cc-EO) and its pure major constituent elemicin. Their antifungal activities were evaluated by the disk diffusion method (DDM) at doses between 0.05 mg/mL and 0.4 mg/mL of Cc-EO and elemicin. The allelopathic effect was evaluated by studying the inhibition of germination and the growth of Lactuca sativa seeds. The chemical composition of Cc-EO was determined by GC-MS and GC-FID analyses. The major constituents of Cc-EO were elemicin (60.5%), α-cadinol (9.0%) and caryophyllene oxide (8.3%). Cc-EO and elemicin were assayed in vitro against 17 fungi of agronomic interest (Aspergillus niger, A. flavus, A. nomius, Penicillium digitatum, P. expansum, Sclerotinia sclerotiorum, S. rolfsii, S. minor, Fusarium graminearum, Myrothecium verrucaria, Corynespora cassiicola, Erwinia psidii, Colletotrichum musae, Alternaria carthami, Rhizoctonia solani, Rhizopus stolonifer and Macrophomina phaseolina). The concentration of Cc-EO (0.4 mg/mL) inhibited 100% of the mycelium growth of seven strains, equal to the fungicide fluazinam, which was used as a positive control. Elemicin showed antifungal activity against all fungi at all concentrations under investigation (above 50%). A strong allelopathic effect was recorded for Cc-EO and elemicin at the dose of 0.28 mg/mL, with the almost total inhibition of germination. This study revealed, for the first time, the strong and remarkable fungicidal and allelopathic effects of Cc-EO and elemicin, an important finding for the agrochemical field.

FaERF2 activates two β-1,3-glucanase genes to enhance strawberry resistance to Botrytis cinerea

Ethylene response factor (ERF) is a class of plant-specific transcription factors that play an important role in plant growth, development, and stress response. However, the underlying mechanism of strawberry ERFs in pathogenic responses against Botrytis cinerea (B. cinerea) remains largely unclear. In this study, we isolated FaERF2, a nucleus-localized ERF transcription factor from Fragaria x ananassa. Transiently overexpressing FaERF2 in strawberry fruits significantly enhances their resistant ability to B. cinerea, while silencing FaERF2 in strawberry fruits enhances their susceptibility to B. cinerea. In addition, we found that FaERF2 could directly bind to the cis-acting element GCC box in the promoters of two β-1,3-glucanase genes, FaBG-1 and FaBG-2, and activate their expression. Finally, both strawberry fruits transient expression followed by B. cinerea inoculation assays and recombinant protein incubation tests collectively substantiated the inhibitory effect of FaBG-1 and FaBG-2 on B. cinerea mycelium growth. These results revealed the molecular regulation mechanism of FaERF2 in response to B. cinerea and laid foundations for creating disease-resistance strawberry cultivar through genome editing approach.

Melaleuca Essential Oil (Melaleuca alternifolia cheel) in the Control of Beans Diseases

Bean cultivation is vital to the global food and economy, especially in Brazil. Facing challenges from diseases that affect production, it is crucial to seek new strategies to maintain productivity and sustainability. Melaleuca alternifolia, known as the tea tree due to its medicinal properties, has little explored potential in controlling diseases in bean plants. The objective of this work was to evaluate the effectiveness of tea tree essential oil in controlling diseases in bean cultivation. In vitro tests were carried out to evaluate bacterial growth, at concentrations of (0.0%, 0.05%, 0.1%, 0.5%, 1% and 2%). And antibiogram with the bacteria Xanthomonas axonopodis pv. phaseoli, in different concentrations (0.0%, 0.05%, 0.1%, 0.5%, 1%, 2% and 3%). For the fungus Pseudocercospora griseola, sporulation tests were carried out, using direct and indirect methods, at concentrations of (0.0%, 0.05%, 0.1%, 0.5%, 1%, 2%, and 3%). Furthermore, for the fungus Colletotrichum lindemuthianum, mycelial growth tests were carried out with the same concentrations. The experiments took place in vivo, with a completely randomized statistical design, involving five replications per treatment and concentrations varying from (0.0%, 0.05%, 0.1%, 0.5%, 1% and 2%). Disease incidence was assessed using a diagrammatic scale, disease severity, Area under the Disease Progress Curve (AACPD) and Area under the Incidence Progress Curve (AACPI). Melaleuca Essential Oil (EO) inhibited the development of fungi and bacteria in in vitro tests starting at 0.5%. In vivo, Melaleuca Essential Oil (EO) showed a significant reduction in the incidence and severity of the disease from 0.5% in both fungi and bacteria. Melaleuca EO can be an effective alternative for disease control in bean cultivation.

Comparative analysis of substrate components, nutritive value, ergosterol distribution, and vitamin D2 enrichment in shiitake mushrooms cultivated on wood substrates

This study investigated shiitake [Lentinula edodes (Berk.)] mushrooms cultivated on seven hardwood and two softwood substrates for production, compositional changes, nutritive value, and ergosterol conversion to vitamin D2 content. The findings demonstrated higher shiitake yields with hardwood species, particularly among Populus ciliata (PC) (163±10.7 g/kg) and Mangifera indica (MI) (112±7.14 g/kg) substrates. Shiitake mushrooms widely utilized hemicellulose (8.93–61.3 %) during mycelial growth, while cellulose (11.9–38.0 %) and lignin (6.66–63.2 %) were mainly consumed during fruiting body development. Additionally, optimization studies on ergosterol conversion to vitamin D2 indicated that 30 KJ m−2 of UV-B exposure significantly enhanced the vitamin D2 content (99.8±2.6 µg/g). Shiitake mushrooms showed a significant difference in ergosterol content (p<0.01) when cultivated on various substrates, with the highest content found on PC (6820±720 µg/g) and Tectona grandis (6810±480 µg/g). Further, the ergosterol conversion rate to vitamin D2 was the highest in the MI substrate (4.39 %), followed by Jacaranda mimosifolia (2.87 %), and was recorded lowest in the Grevillea robusta (1.6 %) substrates. Shiitake mushrooms cultivated on different wood substrates have also shown significant differences (p<0.05) in their nutritional composition. Overall, the study highlights the potential of shiitake mushrooms cultivated on various wood substrates to provide significant nutrients and vitamin D2 content.