Colletotrichum Coccodes Research Articles

Identification of specific genes as molecular markers for rapid and accurate detection of oil-tea Camellia anthracnose pathogen Colletotrichum fructicola in China.

Camellia anthracnose is caused by multiple Colletotrichum species, resulting in severe yield losses of oil-tea Camellia. Colletotrichum fructicola is one of the major anthracnose pathogens of oil-tea Camellia worldwide. However, developing unique molecular markers for the rapid and accurate detection of Colletotrichum fructicola from diverse Colletotrichum species, as well as early monitoring and effective control of the disease, remains largely unexplored. C. fructicola-specific genes were obtained using a BLAST search of the sequences of predicted genes in C. fructicola against the genome sequences of Colletotrichum fungal pathogens. In this study, Colletotrichum fructicola-specific molecular markers were developed for rapid and accurate detection of C. fructicola among Camellia anthracnose causing fungal pathogens. Using genomic DNA-based end-point PCR and qPCR, three C. fructicola-specific genes with the ability to distinguish C. fructicola from other oil-tea Camellia anthracnose-related Colletotrichum species, including Colletotrichum camelliae, Colletotrichum gloeosporioides, and Colletotrichum siamense, and oil-tea Camellia fungal pathogens belonging to the genus Neopestalotiopsis, Pestalotiopsis, and Alternaria, were validated as molecular markers. In addition, these three molecular markers were highly sensitive to detecting C. fructicola using DNA extracted from the inoculated leaves of oil-tea Camellia. These findings enable us to rapidly and uniquely detect the Camellia anthracnose disease caused by Colletotrichum fructicola, which will equip farmers with an effective tool for monitoring Camellia anthracnose disease in the field and taking timely control measurements in advance.

Plant-derived citronellol can significantly disrupt cell wall integrity maintenance of Colletotrichum camelliae

Anthracnose, a fungal disease, commonly infects tea plants and severely impacts the yield and quality of tea. One method for controlling anthracnose is the application of citronellol, a plant extract that exhibits broad-spectrum antimicrobial activity. Herein, the physiological and biochemical mechanism by which citronellol controls anthracnose caused by Colletotrichum camelliae was investigated. Citronellol exhibited excellent antifungal activity based on direct and indirect mycelial growth inhibition assays, with EC50 values of 76.88 mg/L and 29.79 μL/L air, respectively. Citronellol also exhibited good control effects on C. camelliae in semi-isolated leaf experiments. Optical and scanning electron microscopy revealed that citronellol caused C. camelliae mycelia to thin, fracture, fold and deform. Transmission electron microscopy revealed that the mycelial cell walls collapsed inward and separated, and the organelles became blurred after treatment with citronellol. The sensitivity of C. camelliae to calcofluor white staining was significantly enhanced by citronellol, while PI staining showed minimal fluorescence, and the relative conductivity of mycelia were not significantly different. Under citronellol treatment, the expression levels of β-1,3-glucanase, chitin synthase, and chitin deacetylase-related genes were significantly decreased, while the expression levels of chitinase genes were increased, leading to lower chitinase activity and increased β-1,3-glucanase activity. Therefore, citronellol disrupted the cell wall integrity of C. camelliae and inhibited normal mycelial growth.

Potentiality of Beneficial Microbe Bacillus siamensis GP-P8 for the Suppression of Anthracnose Pathogens and Pepper Plant Growth Promotion.

This study was carried out to screen the antifungal activity against Colletotrichum acutatum, Colletotrichum dematium, and Colletotrichum coccodes. Bacterial isolate GP-P8 from pepper soil was found to be effective against the tested pathogens with an average inhibition rate of 70.7% in in vitro dual culture assays. 16S rRNA gene sequencing analysis result showed that the effective bacterial isolate as Bacillus siamensis. Biochemical characterization of GP-P8 was also performed. According to the results, protease and cellulose, siderophore production, phosphate solubilization, starch hydrolysis, and indole-3-acetic acid production were shown by the GP-P8. Using specific primers, genes involved in the production of antibiotics, such as iturin, fengycin, difficidin, bacilysin, bacillibactin, surfactin, macrolactin, and bacillaene were also detected in B. siamensis GP-P8. Identification and analysis of volatile organic compounds through solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) revealed that acetoin and 2,3-butanediol were produced by isolate GP-P8. In vivo tests showed that GP-P8 significantly reduced the anthracnose disease caused by C. acutatum, and enhanced the growth of pepper plant. Reverse transcription polymerase chain reaction analysis of pepper fruits revealed that GP-P8 treated pepper plants showed increased expression of immune genes such as CaPR1, CaPR4, CaNPR1, CaMAPK4, CaJA2, and CaERF53. These results strongly suggest that GP-P8 could be a promising biocontrol agent against pepper anthracnose disease and possibly a pepper plant growth-promoting agent.

Elucidating the impact of environmental factors on the growth of Colletotrichum coccodes strains isolated from potato tubers in Great Britain

Black dot and silver scurf caused by Colletotrichum coccodes and Helminthosporium solani, respectively, are tuber blemish diseases affecting quality in the fresh and pre-pack potato industry. In the last 20 years, the importance of high-quality tuber appearance has increased considerably due to the growing demand for washed and pre-packed potatoes in the UK. Changing climate characterised by rising temperatures and wetter summers is a threat as this will favour the development of pathogens such as C. coccodes in the soil increasing the risk of food spoilage. Moreover, both diseases can develop not only in the field but also after harvest, with postharvest storage temperatures being a crucial factor in controlling fungal growth. Furthermore, anecdotal evidence showed differences on the aggressiveness of black dot depending on its origin (i.e. England and Scotland) on potato tubers. Silver scurf and black dot are difficult to differentiate as they present similar phenotypes characterised by silvery lesions making it challenging for managers to take the necessary corrective action during storage. Hence, the aim of this study was to give a general insight into the ecological conditions affecting the establishment of the causal agent of potato black dot in the field, and black dot and silver scurf during the supply chain. Therefore, invitro experiments were designed to study the growth rate and lag times simulating both scenarios respectively: on soil extract agar (SEA) media at different temperatures (4, 11, 15 °C) and matric potentials (control [unmodified] and − 1.4 MPa [modified]); and on natural potato dextrose agar (NPDA) for different temperatures (4, 11, 15 and 20 °C) at 99 % relative humidity (RH) for 25 days. When simulating the field environment, drier conditions (matric potential = −1.4 MPa) reduced fungal growth for both isolates by 0.1 cm day−1 at the temperature of 15 °C, suggesting temperature as the main limiting factor for the growth of C. coccodes in the soil. The causal agent of black dot exhibited a faster growth rate under retailer-like conditions (i.e., 15 °C) compared to H. solani. Understanding the environmental influence on both the pathogen and the crop is vital for proper disease management to help reduce food loss and waste.

Complete genome analysis of a novel hypovirus in the phytopathogenic fungus Monilinia fructicola.

Monilinia fructicola is one of the most devastating fungal diseases of rosaceous fruit crops, both in the field and postharvest, causing significant yield losses. Here, we report the discovery of a novel positive single-stranded RNA virus, Monilinia fructicola hypovirus 3 (MfHV3), in a strain (hf-1) of the phytopathogenic fungus Monilinia fructicola. The complete genome of MfHV3 is 9259 nucleotides (nt) in length and contains a single large open reading frame (ORF) from nt position 462 to 8411. This ORF encodes a polyprotein with three conserved domains, namely UDP-glycosyltransferase, RNA-dependent RNA polymerase (RdRp), and DEAD-like helicase. The MfHV3 polyprotein shares the highest similarity with Colletotrichum camelliae hypovirus 1. Phylogenetic analysis indicated that MfHV3 clustered with members of the genus Betahypovirus within the family Hypoviridae. Taken together, the results of genomic organization comparisons, amino acid sequence alignments, and phylogenetic analysis convincingly show that MfHV3 is a new member of the genus Betahypovirus, family Hypoviridae.

Antifungal Potential of Carnosic Acid from Salvia somalensis against Phytopathogenic Fungi

The aims of the present study were (i) to characterize the dichloromethane extract of the fresh aerial parts of S. somalensis, cultivated in Liguria (Italy), (ii) to quantify carnosic acid production and (iii) to find an eco-friendly alternative approach to control diseases caused by phytopathogenic fungi. The phytochemical investigation yielded several known terpenoids, as well as a diterpene, 4α,9α-epoxy-2H-dibenzo[a,d]cyclohepten-7(5H)-one, not previously described as a plant metabolite before. The results showed a noteworthy quantity of carnosic acid (113.90 µg/mg of dried extract). The potential antifungal activity of the plant surface extract and carnosic acid against five phytopathogenic fungi (Colletotrichum coccodes, Fusarium oxysporum, Sclerotinia sclerotiorum, Botrytis cinerea and Rhizoctonia solani) was considered. A complete inhibition of C. coccodes, S. sclerotiorum and R. solani mycelium growth was observed by carnosic acid at 500 µg/mL. High inhibition values were observed against B. cinerea and F. oxysporum compared to reference active ingredients. Four different B. cinerea strains exhibited a pronounced sensitivity to carnosic acid, as well as those originating from agricultural crop scenarios where a high load of active ingredient for gray mold control was historically adopted. Additionally, the formation and development of the germinative tube in B. cinerea were greatly slowed down.

First report of leaf spot caused by Colletotrichum camelliae in mung beans (Vigna radiata (L.) R. Wilczek) in South Korea.

Mung bean (Vigna radiata (L.) R. Wilczek) is a legume with high nutritional and economic value that is cultivated widely across Asia (Kang et al. 2014). In March 2022, a leaf spot disease in mung bean was observed at the Gangneung-Wonju National University Experimental farm (Gangneung, South Korea, 37.77°N, 128.86°E). The affected plants had irregular brown-gray leaf spots, and the bottom of the leaves showed concentric brown-gray rings that eventually progressed to necrotic lesions. Regardless of the cultivar, approximately 30% of the plants in the field were infected. To isolate the pathogen, the affected leaves were surface-sterilized by washing with 70% ethanol for 1 min, followed by washing with 2% NaClO for 2 min, then rinsing with sterile distilled water. We placed 3-mm sized diseased lesions on potato-dextrose agar (PDA), then incubated them at 27 ± 1 °C in the dark for 7 days and we obtained 1 isolate (CC1). The fungus on PDA had white aerial mycelia that became gray toward the center. Single spore cultures were obtained from fungal isolate. Isolated conidia were single celled, hyaline, cylindrical, and measured between 20.75 to 22.07 μm × 5.85 to 6.92 μm (n = 20), similar to other reports of C. camelliae(Wang et al. 2016). Mycelium from the single spore isolate was used for DNA extraction using Exgene™ Plant SV / (GeneAll®, Cat.No. 117-152), and we amplified the ITS region with primers ITS1 + ITS2 and ITS3 + ITS4, a portion of the actin gene with primers ACT-512F + 738R, and a portion of the beta-tubulin gene with primers BT2aF + BT2bR (Carbone et al. 1999; Glass et al. 1995; White et al. 1990). The amplified regions were sequenced by by Macrogen® (Seoul, South Korea). Sequences were deposited under GenBank accession numbers OR523262 (ITS), OR582483 (Actin), and OR566953 (beta-tubulin). MegaBLAST analysis of the ITS1, ITS2, ACT, and TUB regions showed 99% (216/217 bp) similarity with C. camelliae strain HNCS-26 (MK041440.1), 99% (303/305 bp) similarity with C. camelliae strain G3 (ON025203.1), 99% (242/244 bp) similarity with C. camelliae strain FWT41 (MN525820.1), and 99% (456/460 bp) with C. camelliae strain LF152 (KJ955239.1), respectively. To fulfill Koch's postulates, we conducted a pathogenicity teston the mung bean cultivar VC1973A (Seonhwanokdu) grown for four weeks at 25 °C with a 16-h day/8-h night cycle, simulating the field conditions when the symptoms were observed. We tested the pathogenicity on six plants , three control and three infected plants. Using three leaf replicates per plant resulting in total of nine leaves per group. Leaves were first injured using a sterile needle then either sterile 5 mm PDA plugs or plugs with C. camelliae were placed on the leaf for control and infected conditions, respectively. Irregular gray leaf spots were observed on the abaxial and adaxial of the infected leaf after 2 weeks, like the symptoms observed in the field. This was observed only on infected leaves and nowhere else on the plant and the control plants had no infection. We re-isolated the pathogen from diseased leaves and identified it as C. camelliae using the same molecular markers described previously, completing Koch's postulate. To the best of our knowledge, this is the first report of leaf spot caused by C. camelliae in mung bean plants in Korea, previously the fungi was reported to infect tea plants in Korea (Hassan et al. 2023). More studies are required to investigate potentially resistant mung bean varieties to minimize future damage caused by this fungus.

Combining the Elicitor Up-Regulated Production of Unusual Linear Diterpene-Derived Variants for an In-Depth Assessment of the Application Value and Risk of the Medicinal and Edible Basidiomycete Schizophyllum commune.

To better assess the practical value and avoid potential risks of the traditionally medicinal and edible basidiomycete Schizophyllum commune, which may arise from undescribed metabolites, a combination of elicitors was introduced for the first time to discover products from cryptic and low-expressed gene clusters under laboratory cultivation. Treating S. commune NJFU21 with the combination of five elicitors led to the upregulated production of a class of unusual linear diterpene-derived variants, including eleven new ones (1-11), along with three known ones (12-14). The structures and stereochemistry were determined by 1D and 2D NMR, HRESIMS, ECD, OR and VCD calculations. Notably, the elongation terminus of all the diterpenes was decorated by an unusual butenedioic acid moiety. Compound 1 was a rare monocyclic diterpene, while 2-6 possessed a tetrahydrofuran moiety. The truncated metabolites 4, 5 and 13 belong to the trinorditerpenes. All the diterpenes displayed approximately 70% scavenging of hydroxyl radicals at 50 μM and null cytotoxic activity at 10 μM. In addition, compound 1 exhibited potent antifungal activity against the plant pathogenic fungi Colletotrichum camelliae, with MIC values of 8 μg/mL. Our findings indicated that this class of diterpenes could provide valuable protectants for cosmetic ingredients and the lead compounds for agricultural fungicide development.

Potato black dot, a tricky disease caused by Colletotrichum coccodes in Inner Mongolia of China

AbstractPotato black dot became an increasingly severe disease in Inner Mongolia, mainly infecting tubers, causing silvery to brown lesions on tuber skin with poorly defined margins and forming black sclerotia later as a sign of skin blemish diseases which significantly affected the yield and fresh market. The C11 and E21 strains isolated from symptomatic tubers of Harqin and Dalate counties were both identified as Colletotrichum coccodes by morphological and molecular identification. Tubers showing silver or brown scurf and black dot on skin were consistent with symptomatic samples collecting from the field in pathogenicity test. This study for pathogenic identification ascertained a tricky disease of potato in Inner Mongolia of China which will lay the foundation for subsequent studies on disease control.

Characterization and pathogenicity of Colletotrichum camelliae causing brown blight disease of tea (Camellia sinensis) in Malaysia

Tea (Camellia sinensis (L.) Kuntze) is a dicotyledonous woody shrub species widely cultivated to produce a beverage made from its leaves. Brown blight is a destructive foliar fungal disease that reduces tea production and degrades quality, resulting in lower market value. Typical brown blight symptoms observed in three commercial tea plantations in Malaysia were characterized as brownish to black lesions on young leaves. The lesions expanded with age, becoming darker and developing into necrotic cells. A total of 45 fungal isolates were isolated from brown blighted tea leaves and identified as Colletotrichum camelliae. Morphological characteristics coupled with universal spacer region and multigene phylogenetic relationships using the internal transcribed spacer (ITS), β-tubulin (tub2) and glyceraldehyde-3-phosphate dehydrogenase (gapdh) were used to accurately identify fungal isolates. The results of the pathogenicity test revealed that C. camelliae was responsible for causing brown blight disease of tea. This study highlights the occurrence of C. camelliae which causes tea brown blight in Malaysia. These findings may assist in disease monitoring, strict quarantine and effective control management of diseased tea plants.

Genome-Wide Identification and Characterization of Tea SGR Family Members Reveal Their Potential Roles in Chlorophyll Degradation and Stress Tolerance

Photosynthesis plays vital roles in plant growth and development. Stay-green (SGR) proteins are responsible for chlorophyll degradation and photosynthetic metabolism. To identify SGR family members and determine their potential functions in tea plants, we identified and cloned three SGR genes. Phylogenetic analysis revealed that the tea SGR homologs were classified into the SGR subfamily (named CsSGR1 and CsSGR2) and the SGRL subfamily (named CsSGRL). Cis-element analysis indicated that the promoters of CsSGR1, CsSGR2 and CsSGRL contained light-, phytohormone- and stress-related elements. Subcellular localization confirmed that CsSGR1 was localized in the chloroplast, while CsSGR2 and CsSGRL were localized in the chloroplast, membrane and nucleus. The RT-qPCR results showed that the three genes in the matures of albino tea cultivars were expressed higher than in the green tea cultivar. However, only CsSGR2-overexpressing tobacco leaves exhibited a yellowish phenotype and significantly lower Fv/Fm values. CsSGR1 and CsSGR2 exhibited similar expression patterns in different tissues after infection with the pathogen Colletotrichum camelliae, which was opposite to the pattern observed for CsSGRL. In addition, CsSGR1 was significantly induced in response to cold stress, SA, JA and ABA in C. camelliae. These findings identified valuable candidate genes for elucidating the mechanism of leaf albinism, stress response and phytohormone signaling in tea plants.

Electronic nose for detecting Colletotrichum coccodes causing anthracnose fruit rots in tomatoes

Electronic nose (EN) technology has several applications targeting various study areas, and food spoilage is one of these sections. This study investigated the ability of the EN, with metal-oxide sensors (MOS), to sense the presence of Colletotrichum coccodes, which cause anthracnose fruit rots, on tomato fruit and to distinguish between different stages and doses of infection. C. coccodes were identified by an appropriate polymerase chain reaction (PCR) program and sequencing, using two different primer sets: ITS1F/ITS4 and Cc1F1/Cc2R1. Three intact homogeneous tomato samples were injected with three different concentrations of conidial fungal suspension: 3 × 104, 3 × 105 and 3 × 106 conidia/ml, and three others were kept as negative controls. Principal component analysis (PCA) was used in analyzing the data acquired from the EN sensors. The results of PCA showed that EN was able to detect the presence of C. coccodes pathogen at early stages (two days of infection and before any symptoms appear). Moreover, EN was able to differentiate between different infection stages. In addition, the concentrations of infected samples on the sixth, eighth and tenth days were clearly differentiated. The use of EN is a promising technique for determining quality assurance and control.

Causes of dangerous fungal diseases of potatoes in the western region of Ukraine due to climate change

Goal. To determine the species composition of pathogens of potato fungal diseases in the western region of the forest-steppe zone under climatic changes.
 Methods. Research was conducted during 2021—2022 on the basis of the Ukrainian Plant Quarantine Research Station of the Institute of Plant Protection using laboratory (identification of pathogens) and field (examination of potato plantations and analysis of tuber material) methods.
 Results. According to the research results, the most common fungal diseases on vegetative plants during the studied period were: anthracnose (Colletotrichum coccodes (Wallr.) S. Hughes), Alternaria solani (Ellis & G. Martin) L.R. Jones & Grout, Alternaria alternata (Fr.) Keissl.), fusarium wilt (Fusarium oxysporum Sсhl.) and late blight (Phytophthora infestans (Mont.) de Bary). As a result of phytopathological analysis of tubers, it was established that the greatest danger during potato storage is caused by pathogens of the genera Fusarium, Phoma, Colletotrichum, Phytophthora, causing fusarium, fomosis, anthracnose, phytophthora and mixed types of rot. the causative agents of fusarium were identified — Fusarium oxysporum Sсhl., F. sambucinum Fuck., F. solani Vart.; phomoza — Rhoma exigua Desm. var. exigua rhizoctonia — Rhizoctonia solani (J. G. Kühn) [teleomorph Thanatephorus cucumeris (A. B. Frank) Donk]; Alternaria solani (Ellis & G. Martin) L.R. Jones & Grout; Alternaria alternata (Fr.) Keissl.; anthracnose — Colletotrichum coccodes (Wallr.) S. Hughes, late blight — Phytophthora infestans (Mont.) de Bary); the share of fusarium was 42.1%, the causative agent of anthracnose — 27.5%.
 Conclusions. Fungal diseases (anthracnose, fusarium wilt) of potatoes, which at the end of the twentieth century were considered to be of limited distribution, have become widespread, which requires their further study in order to optimize crop protection.

Diversity of Genetic and Vegetative Compatibility Group of Colletotrichum coccodes Isolates from Chile Using Amplified Fragment Length Polymorphism Markers.

Colletotrichum coccodes (Wallr.) Hughes is an asexual fungus with five vegetative compatibility groups. It was postulated that C. coccodes was isolated at the center of origin of potato at one time, and due to the movement of potato around the globe, the fungus was established on each continent but became bottlenecked and genetically unable to form stable heterokaryons via vegetative compatibility grouping (VCG) studies. The objectives of this study were (i) to determine if the VCGs around the world are related to the VCGs in Chile, (ii) to determine the diversity of C. coccodes populations in Chile, and (iii) to find any evidence for a cryptic sexual life cycle for this fungus. Worldwide C. coccodes populations have been found to be genetically correlated and belong to one or more C. coccodes-identified VCGs. The most distributed VCG in Chile was VCG2, which is the most common VCG in North America. We hypothesize that one or more VCGs had spread from Chile to the rest of the world. Precautions and further studies should be investigated by using other molecular markers and gene sequencing.

Attempts to Use Hemp (Cannabis sativa L. var. sativa) Inflorescence Extract to Limit the Growth of Fungi Occurring in Agricultural Crops

The primary objective of this investigation was to assess the potential applicability of hemp (Cannabis sativa L. var. sativa) lateral inflorescence extract in mitigating the growth of fungi, including phytopathogens, on agricultural plants. The extract, comprising a blend of biologically active compounds, holds promise for integration into contemporary plant protection methodologies. The research involved a comprehensive analysis of the extract’s chemical composition, encompassing the determination of total polyphenol and flavonoid content (utilizing spectrophotometric methods), antioxidant activity (evaluated through the DPPH method employing synthetic 2,2-diphenyl-1-picrylhydrazyl radical), and cannabinoid content (analyzed using HPLC techniques). Additionally, this study employed the poisoned substrate method to gauge the impact of 5, 10, and 20% extract concentrations on the growth of various microfungi, including Alternaria alternata, Botrytis cinerea, Colletotrichum coccodes, Fusarium avenaceum, F. culmorum, F. graminearum, F. oxysporum, F. sporotrichioides, and Trichoderma koningii. The hemp extract demonstrated a substantial presence of total polyphenolic compounds, with polyphenol and flavonoid concentrations measuring 149.65 mg/mL and 1.55 mg/mL, respectively. Furthermore, the extract contained cannabinoids at a concentration of 0.12%. The most pronounced antifungal activity was observed with the 20% extract, particularly against T. koningii (62.22–84.79%), C. coccodes (61.65–81.82%), and B. cinerea (45.00–75.42%). However, the efficacy of hemp extracts exhibited large differences against Fusarium spp. (3.10–72.95%), dependent on the specific extract and fungus strain. Introduction of hemp extracts to the substrate induced a reduction in substrate pigment and a discernible color alteration in the mycelium to a lighter shade compared to the control. These findings mark the initial phase in the exploration of practical applications for plant extracts, setting the groundwork for subsequent field trials to ascertain the extract’s impact on phytotoxicity and the health status of agricultural plants.

A tau class glutathione S-transferase in tea plant, CsGSTU45, facilitates tea plant susceptibility to Colletotrichum camelliae infection mediated by jasmonate signaling pathway.

Tea plant [Camellia sinensis (L.) O. Kuntze], as one of the most important commercial crops, frequently suffers from anthracnose caused by Colletotrichum camelliae. The plant-specific tau (U) class of glutathione S-transferases (GSTU) participates in ROS homeostasis. Here, we identified a plant-specific GST tau class gene from tea plant, CsGSTU45, which is induced by various stresses, including C. camelliae infection, by analyzing multiple transcriptomes. CsGSTU45 plays a negative role in disease resistance against C. camelliae by accumulating H2 O2 . JA negatively regulates the resistance of tea plants against C. camelliae, which depends on CsGSTU45. CsMYC2.2, which is the key regulator in the JA signaling pathway, directly binds to and activates the promoter of CsGSTU45. Furthermore, silencing CsMYC2.2 increased disease resistance associated with reduced transcript and protein levels of CsGSTU45, and decreased contents of H2 O2 . Therefore, CsMYC2.2 suppresses disease resistance against C. camelliae by binding to the promoter of the CsGSTU45 gene and activating CsGSTU45. CsJAZ1 interacts with CsMYC2.2. Silencing CsJAZ1 attenuates disease resistance, upregulates the expression of CsMYC2.2 elevates the level of the CsGSTU45 protein, and promotes the accumulation of H2 O2 . As a result, CsJAZ1 interacts with CsMYC2.2 and acts as its repressor to suppress the level of CsGSTU45 protein, eventually enhancing disease resistance in tea plants. Taken together, the results show that the JA signaling pathway mediated by CsJAZ1-CsMYC2.2 modulates tea plant susceptibility to C. camelliae by regulating CsGSTU45 to accumulate H2 O2 .

Detection of Colletotrichum coccodes by Real-Time PCR

Detection of Colletotrichum coccodes by Real-Time PCR

Analysis of Bioactive Compounds Produced by Bacillus mojavensis ZA1 and Their Antagonistic Effect on Colletotrichum coccodes by GC-MS.

The plant disease Colletotrichum coccodes, which lowers potato yields, poses a severe danger to the booming potato industry. Isolated plant endophytic bacteria from highland pasture can produce a variety of metabolites that lessen the risk that the pathogen C. coccodes poses to plant growth and development. Therefore, the objective of our work was to assess substances with antipathogenic properties made by the endophytic bacteria Bacillus mojavensis ZA1. Gas chromatography-mass spectrometry (GC-MS) was used in our investigation to accomplish a thorough structural elucidation of the antipathogenic compounds produced by the endophytic bacterial strain B. mojavensis ZA1. The results showed that the metabolites extracted from ethyl acetate as an extractant were the most effective in inhibiting the pathogen C. coccodes, with 60.95% inhibition. Thirty-five distinct chemicals, including acids, esters, ketones, alcohols, amino acid ammonium salts, cyclic ethers, aromatic hydrocarbons, and heterocyclic compounds, were among the metabolites that may inhibit C. coccodes. Further analysis of the chemical groups in the compound structures revealed the potential of driving groups, such as hydroxyl, carbonyl, ester, benzene, carbon-carbon double bonds, and carbon rings, that prevent C. coccodes from performing its function. This study opens up new opportunities for plant protection programs by demonstrating that natural chemicals produced by B. mojavensis ZA1 can be used as candidates for cutting-edge plant disease management treatments.

Inhibition of oil tea anthracnose by natural product extracts from Bacillus and Pseudoalteromonas isolates from mangrove soil

This study investigates the potential of natural products derived from two mangrove soil bacteria, GP521A and GP3R5, in anthracnose management in oil tea. Based on 16s rDNA sequencing, GP521A and GP3R5 were identified as Bacillus velezensis and Pseudoalteromonas caenipelagi, respectively. Both bacteria showed strong antagonistic effects towards multiple fungal pathogens on dual cultural plates. The ethyl acetate extracts of fermentation cultures of GP521A (FEGP5) and GP3R5 (FEGP3) significantly inhibited mycelial growth of both Colletotrichum camelliae MC171, C. fructicola CF-1 and Pyricularia oryzae P131 at 100 and 200 μg/mL, respectively. Furthermore, FEGP5 and FEGP3 significantly inhibited conidiation, conidial germination and appressorial formation in C. camelliae MC171 at 50 μg/mL, with stronger inhibitory effects observed in the latter. On detached oil tea leaves, 100 μg/mL of FEGP5 and FEGP3 resulted in ~ 98.0% and 97.5% reduction in diseased areas, respectively, when applied before MC171 inoculation, whereas the reduction was approximately 55.0% and 77.6%, respectively, in the curative treatments. In fresh fruits, both extracts also significantly inhibited disease development, either in preventative or curative treatments. Moreover, FEGP5 and FEGP3 demonstrated significantly lower aquatic toxicity than prochloraz at the same concentrations towards a commonly used bioindicator, Artemia salina. In conclusion, this study demonstrates the potential of marine microbes derived natural products in development of environmentally compatible biopesticides to control anthracnose in oil tea.

Evaluation of some bioactive compounds of <i>Azadirachta indica</i> extracts and its application as safe fungicide against different plant pathogenic fungi

Extracts of leaves, seeds and twigs of Azadirachta indica was carried out using Soxhlet extraction technique. These extracts were subjected to percent yield, in vitro phytochemical screening and antifungal activities (minimum fungicidal concentration (MFC), minimum inhibitory concentration (MIC), zone of inhibition and spore germination assay) against plant pathogenic fungi Cladosporium fulvum, Colletotrichum coccodes, Fusarium oxysporum and Rhizoctonia solani. The Soxhlet extractive solvents were methanol, ethanol, chloroform, ethyl acetate and n–hexane. The maximum extractive yield were calculated in ethanol leaves (26±1.5%), methanol leaves (22±01%), n–hexane seeds (32±0.8%) and ethanol seeds (24±01%), while twigs calculated minimum extractive yield. The phytochemicals screening findings confirmed the occurrence of terpenoids, phenols, flavonoids, glycosides, alkaloids, tannins and saponins. The antifungal activities observed that leaves and seeds extracts of neem might cause the inhibition of mycelium and spore germination of tested fungi, though the antifungal activities rate of under study fungal strains diverse with dissimilar concentration and nature of extracts. However the entire concentrations of extract and crude extract especially the methanol and ethanol extracts of neem seeds and leaves reduce the plant pathogenic fungi growth at noteworthy rate. It was concluded from our results that neem leaves and seeds extracts were effectual as antifungal agents against the entire under study fungal strains however the most sensitive fungi were Rhizoctonia solani and Fusarium oxysporum. The findings acquired from this study revealed that chemical constituents from neem seeds and leaves may be formulated as latent agrochemical fungicides.