Plant Pathogenic Colletotrichum Research Articles

Evaluation of ALA-capped silver, copper, and silver–copper nanoparticles for controlling fungal plant pathogens

Phytopathogenic fungi significantly threaten global food security, causing substantial yield and quality losses. Sustainable solutions are urgently needed to combat these agricultural pathogens. This study explored the potential of silver (Ag), copper (Cu), and combined Ag/Cu nanoparticles capped with aminolevulinic acid (ALA) as antifungal agents. The nanoparticles (ALAAg, ALACu, and ALAAgCu) were synthesized via photoreduction and characterized using various techniques (UV–Vis, TEM, XRD, Zeta potential). Their antifungal activity against four key plant pathogens (Alternaria grandis, Colletotrichum truncatum, Corynespora cassiicola, and Fusarium oxysporum) was evaluated using poisoned food techniques. Notably, ALAAgCuNPs demonstrated superior antifungal activity compared to a conventional fungicide against two fungal strains. Even at lower concentrations, ALAAgCuNPs exhibited fungistatic effects comparable to those of the control. These promising results suggest the potential of ALAAgCu NPs as a broad-spectrum, potentially eco-friendly alternative for fungal control in plants and seeds. This approach is crucial for ensuring crop health, harvest quality, and food safety.

Fungal plant pathogen Colletotrichum shisoi identified as a potential biological control agent of invasive Perilla frutescens in the United States

ABSTRACT Perilla frutescens (L.) Britton, an annual plant in the mint family, is considered invasive in the United States where it excludes native vegetation in natural areas and can cause respiratory illness in livestock. An effective biological control agent would improve perilla management, but none have been developed or proposed. This study investigated the biocontrol potential of a fungal pathogen, Colletotrichum shisoi, recently found infecting perilla in North America. The growth rates and morphology of seven Colletotrichum shisoi isolates were recorded. A virulence assay was performed on two perilla accessions, and the number and size of foliar lesions produced were used to select a single isolate, Colletotrichum shisoi isolate 21-072, exhibiting consistently high virulence for further evaluation of biocontrol efficacy and host specificity. Treatment with 0.5 mL of 1 × 107 spores/mL H2O caused a 52% reduction in shoot height and 84% reduction in root length of invasive perilla seedlings compared to a control treatment (P < 0.001). Seedlings treated with 1 × 108 spores/mL had a 100% mortality rate. Formulation of inoculum in a 1:1 water:oil emulsion reduced dew period requirements for causing >50% plant mortality from 48 to 24 h, but oil emulsions exhibited a mild phytotoxic effect on seedlings. Four additional perilla accessions were susceptible to C. shisoi, and none of 34 other species included in host range experiments developed disease symptoms following inoculation. These results suggest C. shisoi 21-072 could be an effective antagonist of perilla and likely poses a low risk of non-target impacts.

Variation in seed-borne microbial communities of Metrosideros excelsa Sol. ex Gaertn. with consequences for germination success

ABSTRACT Seed endophytic bacteria and fungi are co-dispersed with seeds and are likely founders of the initial endophytic microbiome in developing seedlings. The effects of the seed microbiome on seedling survival and growth are of particular interest for their roles in protection against pathogens and plant resistance to environmental stress. The fungal pathogen Austropuccinia psidii (G. Winter) Beenken is the causal agent of myrtle rust, which infects more than 480 species of Myrtaceae globally and poses a severe threat to New Zealand endemic species such as Metrosideros excelsa Sol. ex Gaertn. We hypothesised that seedlings of M. excelsa may contain seed-derived microbial communities that may contribute to variation in susceptibility to A. psidii. Culture based methods were used to recover 22 species of fungi (n = 412 isolates) and 16 bacterial taxa (n = 156 isolates) from 1580 M. excelsa seeds collected from 30 trees. Our results indicate broad variation in the isolation frequency and species composition of seed-borne microorganisms among individual trees: while seeds sampled from four trees were free of culturable microorganisms, the other 26 trees accumulated up to eight culturable taxa (both bacteria and fungi) in their seeds, including some species known to be beneficial endophytes or phytopathogens. The most frequently isolated fungal species belong to genera Aureobasidium, Cladosporium, Penicillium, and Pestalotiopsis. These fungi were often isolated from seeds also containing bacteria of the genera Bacillus, Erwinia, and Methylobacterium. At the same time, seeds collected from four trees contained known plant pathogens Colletotrichum aff. fioriniae (Marcelino & Gouli) Pennycook, Neofusicoccum sp., and Robbsia aff. andropogonis (Smith) Lopes-Santos et al., which could affect seed germination. This is the first report of bacterial and fungal communities residing in seeds of endemic New Zealand trees and the potential effects of seed-borne microbiomes on germination.

Antifungal and Phytotoxic Activities of Isolated Compounds from Helietta parvifolia Stems

The identification of natural and environmentally friendly pesticides is a key area of interest for the agrochemical industry, with many potentially active compounds being sourced from numerous plant species. In this study, we report the bioassay-guided isolation and identification of phytotoxic and antifungal compounds from the ethyl acetate extract of Helietta parvifolia stems. We identified eight compounds, consisting of two coumarins and six alkaloids. Among these, a new alkaloid, 2-hydroxy-3,6,7-trimethoxyquinoline-4-carbaldehyde (6), was elucidated, along with seven known compounds. The phytotoxicity of purified compounds was evaluated, and chalepin (4) was active against Agrostis stolonifera at 1 mM with 50% inhibition of seed germination and it reduced Lemna pausicotata (duckweed) growth by 50% (IC50) at 168 μM. Additionally, we evaluated the antifungal activity against the fungal plant pathogen Colletotrichum fragariae using a thin-layer chromatography bioautography assay, which revealed that three isolated furoquinoline alkaloids (flindersiamine (3), kokusagenine (7), and maculine (8)) among the isolated compounds had the strongest inhibitory effects on the growth of C. fragariae at all tested concentrations. Our results indicate that these active natural compounds, i.e., (3), (4), (7), and (8), could be scaffolds for the production of more active pesticides with better physicochemical properties.

Antifungal Effect of Bacillus velezensis ZN-S10 against Plant Pathogen Colletotrichum changpingense and Its Inhibition Mechanism

Antifungal Effect of Bacillus velezensis ZN-S10 against Plant Pathogen Colletotrichum changpingense and Its Inhibition Mechanism

Phylogeographic and Phylogenomic Structure of the Quarantine Plant Pathogen Colletotrichum liriopes, Including New Reports in the United States.

Global agricultural trade has accelerated the emergence and re-emergence of new plant pathogens. In the United States, the fungal pathogen Colletotrichum liriopes is still considered a foreign quarantine pathogen that affects ornamental plants (i.e., Liriope spp.). Even though this species has been reported in East Asia on various asparagaceous hosts, its first and only report in the United States was in 2018. However, that study used only ITS nrDNA for identification, and no available culture or voucher specimen was maintained. The main objective of the present study was to determine the geographic and host distribution of specimens identified as C. liriopes. To accomplish this, new and existing isolates, sequences, and genomes obtained from various hosts and geographic locations (i.e., China, Colombia, Mexico, and the United States) were compared with the ex-type of C. liriopes. Multilocus phylogenetic (ITS, Tub2, GAPDH, CHS-1, and HIS3), phylogenomic, and splits tree analyses revealed that all the studied isolates/sequences form a well-supported clade with little intraspecific variation. Morphological characterizations support these findings. The minimum spanning network, low nucleotide diversity, and negative Tajima's D from both multilocus and genomic data suggest that there was a recent movement/invasion of a few East Asian genotypes to other countries where the ornamental plants are produced (e.g., South America) and subsequently to the importing countries, such as the United States. The study reveals that the geographic and host distribution of C. liriopes sensu stricto is expanded to the United States (i.e., at least Maryland, Mississippi, and Tennessee) and on various hosts in addition to Asparagaceae and Orchidaceae. The present study produces fundamental knowledge that can be used in efforts to reduce costs or losses from agricultural trade and to expand our understanding of pathogen movement.

Bacillus spp. isolated from pepper leaves and their function and inhibition of the fungal plant pathogen Colletotrichum scovillei

BackgroundPepper is a popular ingredient in many Chinese households; however, anthracnose caused by Colletotrichum spp. has greatly decreased pepper production. The genus Bacillus is widely known for its important role in the development and protection of plants from phytopathogenic fungi.ResultsFifty-eight endophytic strains were isolated from pepper leaves and tested for antifungal activity in this study. Specifically, L1-7 and L3-5 displayed growth inhibition rates of 79 and 80% against C. scovillei mycelium, respectively, while 25 of these strains all had growth inhibition rates of greater than 60%. Bacillus amyloliquefaciens and B. velezensis, based on culture and morphological identification with 16S rDNA and gyrB gene sequence analyses, were determined to be the respective species L1-7 and L3-5. Additionally, it was discovered that these two antagonistic endophytic bacteria could fix nitrogen, produce indoleacetic acid (IAA) and have a high salt tolerance. Pot experiments again showed excellent control of the pathogen C. scovillei by L1-7 and L3-5, with 80.64 and 73.39% control, respectively. Therefore, B. amyloliquefaciens (L1-7) and B. velezensis (L3-5) can be applied as biological control agents to protect peppers against C. scovillei-caused anthracnose.ConclusionBacillus amyloliquefaciens (L1-7) and B. velezensis (L3-5) can be applied as biological control agents to protect peppers against C. scovillei-caused anthracnose. Thus, they can serve as promising biocontrol agents and plant growth promoters, and future research on the pertinent bacteria will serve as a useful guide for the creation of microbial resources.

Stability and bioactivity evaluation of black pepper essential oil nanoemulsion

Black pepper essential oil has the same disadvantages as other plant essential oils, such as volatilization, high sensitivity to light and heat and poor water solubility, which leads to great limitations in application. This study improved the stability and antibacterial properties of black pepper essential oil (BPEO) based on a nano-emulsification process. Tween 80 was selected as the emulsifier to prepare the BPEO nanoemulsion. Gas chromatograph - mass spectrometer (GC-MS) was used to analyze the composition of BPEO, of which d-limonene was the main component (37.41%). After emulsification, black pepper nanoemulsion was obtained (droplet size was 11.8 nm). The water solubility and stability of the emulsions at 25 °C were also improved with decreasing particle size. Antimicrobial properties of plant pathogens (Colletotrichum gloeosporioides, Botryodiplodia theobromae) and foodborne pathogens (Staphylococcus aureus, Escherichia coli) were evaluated by disk diffusion and other techniques for determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). With 12.5 mg mL−1 MIC and 25 mg mL−1 MBC, BPEO inhibited the growth of two tested plant pathogens and two foodborne pathogens. Essential oils (EO) were encapsulated in a nanoemulsion system to enhance the bacteriostatic effect of essential oils and reduce MIC and MBC concentrations. After emulsification, the biological activity (antimicrobial and antioxidant) of the BPEO nanoemulsion was considerably improved, nano-emulsification had certain significance for the study of EOs.

Selective deployment of virulence effectors correlates with host specificity in a fungal plant pathogen.

The hemibiotrophic fungal plant pathogen Colletotrichum orbiculare is predicted to secrete hundreds of effector proteins when the pathogen infects cucurbit crops, such as cucumber and melon, and tobacco (Nicotiana benthamiana), a distantly related Solanaceae species. Here, we report the identification of sets of C.orbiculare effector genes that are differentially required for fungal virulence to two phylogenetically distant host species. Through targeted gene knockout screening of C.orbiculare 'core' effector candidates defined based on in planta gene expression, we identified: four host-specific virulence effectors (named effector proteins for cucurbit infection, or EPCs) that are required for full virulence of C.orbiculare to cucurbit hosts, but not to the Solanaceae host N.benthamiana; and five host-nonspecific virulence effectors, which collectively contribute to fungal virulence to both hosts. During host infection, only a small subset of genes, including the host-specific EPC effector genes, showed preferential expression on one of the hosts, while gene expression profiles of the majority of other genes, including the five host-nonspecific effector genes, were common to both hosts. This work suggests that C.orbiculare adopts a host-specific effector deployment strategy, in addition to general host-blind virulence mechanisms, for adaptation to cucurbit hosts.

Antifungal Activity of Selenium Nanoparticles Obtained by Plant-Mediated Synthesis.

The continuous need to satisfy world food demand has led to the search for new alternatives to combat economic losses in agriculture caused by phytopathogenic fungi. These organisms cause plant diseases, reducing their productivity and decreasing fruit quality. Among the new tools being explored is nanotechnology. Nanoparticles with antimicrobial properties could be an excellent alternative to address this problem. In this work, selenium nanoparticles (SeNPs) were obtained using plant extracts of Amphipterygium glaucum leaves (SeNPs-AGL) and Calendula officinalis flowers (SeNPs-COF). Characterization of the SeNPs was performed and their ability as antifungal agents against two commercially relevant plant pathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides, was evaluated. Assays were performed with different concentrations of SeNPs (0, 0.25, 0.5, 1.0, and 1.7 mg/mL). It was observed that both SeNPs had antifungal activity against both plant pathogens at concentrations of 0.25 mg/mL and above. SeNPs-AGL demonstrated better antifungal activity and smaller size (around 8.0 nm) than SeNPs-COF (134.0 nm). FTIR analysis evidenced the existence of different functional groups that constitute both types of SeNPs. There are factors that have to be considered in the antimicrobial activity of SeNPs such as nanoparticle size and phytochemical composition of the plant extracts used, as these may affect their bioavailability.

Design, synthesis and antifungal activity of novel pyrazole amides derivates

With the help of active substructure splicing strategy, 36 novel pyridine ring pyrazolamide derivatives were designed and synthesized. The structures of those compounds were confirmed and characterized by 1H NMR, 13C NMR, FT-IR, and HRMS. The compound 2i was identified by X-ray crystal diffraction. The fungicidal effects of the pyrazolamide derivates against four plant pathogenic fungi, Colletotrichum gloeosporioides, Fusarium oxysporum, Sphaeropsis sapinea and Fusarium moniliforme, was determined by the mycelial growth rate. The results showed that the designed compounds had certain antifungal activity at the concentration of 200 mg/L. Compared with the positive control carbendazim, compounds 1e, 1g and 1h exhibited stronger antifungal activity on Sphaeropsis sapinea and Fusarium moniliforme. The antifungal activity of compound 1a-1s (R1 = H) was better than that of compound 2a-2p (R1 = CH3). Compounds 1d, 1e, 1g, 1h, 1i, 2g and 2i showed good antifungal activity, and the introduction of halogen groups (except F) on benzene ring may have an important effect on biological activity. Compound 1g had a good inhibitory effect on the growth of a variety of plant pathogenic fungi. Molecular docking revealed that the -CH3 group at R1 position would reduce the binding affinity between these compounds and receptor, which would reduce the antifungal activity of the compound. Compound 1g is promising to become the lead compound of pesticide in the future, which is worthy of further study.

Proteinaceous Effector Discovery and Characterization in Plant Pathogenic Colletotrichum Fungi.

Anthracnose caused by plant pathogenic Colletotrichum fungi results in large economic losses in field crop production worldwide. To aid the establishment of plant host infection, Colletotrichum pathogens secrete numerous effector proteins either in apoplastic space or inside of host cells for effective colonization. Understanding these effector repertoires is critical for developing new strategies for resistance breeding and disease management. With the advance of genomics and bioinformatics tools, a large repertoire of putative effectors has been identified in Colletotrichum genomes, and the biological functions and molecular mechanisms of some studied effectors have been summarized. Here, we review recent advances in genomic identification, understanding of evolutional characteristics, transcriptional profiling, and functional characterization of Colletotrichum effectors. We also offer a perspective on future research.

Three interesting fungal species associated with the Asian House Gecko in Kunming, China

A dead Asian House Gecko, infected with multiple species of fungi, was found floating in a jug of water inside a building in Kunming, China. The dead gecko was taken to the mycology laboratory at the Kunming Institute of Botany, Chinese Academy of Sciences and different fungal species were isolated. Phylogenetic analyses were carried out on the resultant isolates based on multiple gene sequences (ITS, LSU, mtSSU, rpb1, rpb2, tub2, Bloc, CAL, CHS-1, GAPDH, tef1-α). In addition to the phylogenetic analyses, morphological characteristics were also used to describe the fungal taxa. The entomopathogenic fungus Basidiobolus ranarum was isolated from the gecko’s inflamed right forelimb, while Beauveria bassiana was isolated from the gecko’s forehead. In addition, the neck skin yielded a common and important plant pathogen Colletotrichum jianxiense. Full descriptions, color plates of macro and micro structures of fungal taxa, and phylogenetic trees to show the placements of fungal taxa are provided. These findings represent either new host records or new country records for the three fungal species.

Endophytic Trichoderma strains isolated from forest species of the Cerrado-Caatinga ecotone are potential biocontrol agents against crop pathogenic fungi.

The indiscriminate use of chemical pesticides increasingly harms the health of living beings and the environment. Thus, biological control carried out by microorganisms has gained prominence, since it consists of an environmentally friendly alternative to the use of pesticides for controlling plant diseases. Herein, we evaluated the potential role of endophytic Trichoderma strains isolated from forest species of the Cerrado-Caatinga ecotone as biological control agents of crop pathogenic fungi. Nineteen Trichoderma strains were used to assess the antagonistic activity by in vitro bioassays against the plant pathogens Colletotrichum truncatum, Lasiodiplodia theobromae, Macrophomina phaseolina, and Sclerotium delphinii isolated from soybean, cacao, fava bean, and black pepper crops, respectively. All Trichoderma strains demonstrated inhibitory activity on pathogen mycelial growth, with maximum percent inhibition of 70% against C. truncatum, 78% against L. theobromae, 78% against M. phaseolina, and 69% against S. delphinii. Crude methanol extracts (0.5 to 2.0 mg mL-1) of Trichoderma strains were able to inhibit the growth of C. truncatum, except Trichoderma sp. T3 (UFPIT06) and T. orientale (UFPIT09 and UFPIT17) at 0.5 mg mL-1, indicating that the endophytes employ a biocontrol mechanism related to antibiosis, together with multiple mechanisms. Discriminant metabolites of Trichoderma extracts were unveiled by liquid chromatography-tandem mass spectrometry-based metabolomics combined with principal component analysis (PCA), which included antifungal metabolites and molecules with other bioactivities. These results highlight the biocontrol potential of Trichoderma strains isolated from the Cerrado-Caatinga ecotone against crop pathogenic fungi, providing support for ongoing research on disease control in agriculture.

Biocontrol Activity of Aspergillus terreus ANU-301 against Two Distinct Plant Diseases, Tomato Fusarium Wilt and Potato Soft Rot.

To screen antagonistic fungi against plant pathogens, dual culture assay (DCA) and culture filtrate assay (CFA) were performed with unknown soil-born fungi. Among the different fungi isolated and screened from the soil, fungal isolate ANU-301 successfully inhibited growth of different plant pathogenic fungi, Colletotrichum acutatum, Alternaria alternata, and Fusarium oxysporum, in DCA and CFA. Morphological characteristics and rDNA internal transcribed spacer sequence analysis identified ANU-301 as Aspergillus terreus. Inoculation of tomato plants with Fusarium oxysporum f. sp. lycopersici (FOL) induced severe wilting symptom; however, co-inoculation with ANU-301 significantly enhanced resistance of tomato plants against FOL. In addition, culture filtrate (CF) of ANU-301 not only showed bacterial growth inhibition activity against Dickeya chrysanthemi (Dc), but also demonstrated protective effect in potato tuber against soft rot disease. Gas chromatography-tandem mass spectrometry analysis of CF of ANU-301 identified 2,4-bis(1-methyl-1-phenylethyl)-phenol (MPP) as the most abundant compound. MPP inhibited growth of Dc, but not of FOL, in a dose-dependent manner, and protected potato tuber from the soft rot disease induced by Dc. In conclusion, Aspergillus terreus ANU-301 could be used and further tested as a potential biological control agent.

Tracking Fungal Growth: Establishment of Arp1 as a Marker for Polarity Establishment and Active Hyphal Growth in Filamentous Ascomycetes.

Polar growth is a key characteristic of all filamentous fungi. It allows these eukaryotes to not only effectively explore organic matter but also interact within its own colony, mating partners, and hosts. Therefore, a detailed understanding of the dynamics in polar growth establishment and maintenance is crucial for several fields of fungal research. We developed a new marker protein, the actin-related protein 1 (Arp1) fused to red and green fluorescent proteins, which allows for the tracking of polar axis establishment and active hyphal growth in microscopy approaches. To exclude a probable redundancy with known polarity markers, we compared the localizations of the Spitzenkörper (SPK) and Arp1 using an FM4-64 staining approach. As we show in applications with the coprophilous fungus Sordaria macrospora and the hemibiotrophic plant pathogen Colletotrichum graminicola, the monitoring of Arp1 can be used for detailed studies of hyphal growth dynamics and ascospore germination, the interpretation of chemotropic growth processes, and the tracking of elongating penetration pegs into plant material. Since the Arp1 marker showed the same dynamics in both fungi tested, we believe this marker can be broadly applied in fungal research to study the manifold polar growth processes determining fungal life.

A New Sesquiterpene Derivative from the Mangrove Endophytic Fungus Trichoderma harzianum (Strain No. R1)

A new sesquiterpene derivative, ethyl hydroheptelidate (1), was isolated from the mangrove endophytic fungus Trichoderma harzianum R1. Its structure was elucidated by comprehensive spectroscopic analyses. This compound showed high antifungal activity against two plant pathogenic fungi, Fusarium oxysporum and Colletotrichum musae, and moderate to weak antibacterial activity against three types of avian pathogenic Escherichia coli: O8, O78, and O101.

Antifungal Activity of Cyclic Tetrapeptide from Bacillus velezensis CE 100 against Plant Pathogen Colletotrichum gloeosporioides.

The aim of this study was to investigate the antifungal activity of a cyclic tetrapeptide from Bacillus velezensis CE 100 against anthracnose-causing fungal pathogen Colletotrichum gloeosporioides. Antifungal compound produced by B. velezensis CE 100 was isolated and purified from ethyl acetate extract of B. velezensis CE 100 culture broth using octadecylsilane column chromatography. The purified compound was identified as cyclo-(prolyl-valyl-alanyl-isoleucyl) based on mass spectrometer and nuclear magnetic resonance analyses. This is the first report of the isolation of a cyclic tetrapeptide from B. velezensis CE 100 culture filtrate. Cyclic tetrapeptide displayed strong antifungal activity at concentration of 1000 µg/mL against C. gloeosporioides mycelial growth and spore germination. Our results demonstrate that the antifungal cyclic tetrapeptide from B. velezensis CE 100 has potential in bioprotection against anthracnose disease of plants caused by C. gloeosporioides.

Different wavelengths of visible light influence the conidial production and tolerance to ultra-violet radiation of the plant pathogens Colletotrichum acutatum and Fusarium fujikuroi

The effects of the visible light wavelengths on germination, mycelial radial growth, and conidial production of the plant pathogens Colletotrichum acutatum and Fusarium fujikuroi were studied. Both fungi were grown on potato dextrose agar medium (PDA) in the dark (control) or on PDA under continuous white, blue, green or red light. In addition, the conidia from each treatment were exposed to UV radiation. The germination and growth of both plant pathogenic fungi were not affected by any of the treatments. C. acutatum produced more conidia when the fungus grew under white and red light. F. fujikuroi produced more conidia in the dark. The tolerances to UV radiation of conidia produced on different light and dark treatments differed for both C. acutatum and F. fujikuroi. Conidia of C. acutatum were at least 30% more tolerant to UV radiation when they were produced under white light than under blue and green light and at least 20% more tolerant than conidia produced in the dark. Conidia of C. acutatum produced under red light were the least tolerant. Conidia of F. fujikuroi produced under white and blue light were at least 30% more UV tolerant than conidia produced in the dark, green, and red light. In conclusion, no differences were found for germination and growth for both fungi under different light regimes and dark; however, significant differences occurred both in production and UV radiation of conidia.

A 3D Printed Device for Easy and Reliable Quantification of Fungal Chemotropic Growth.

Chemical gradients are surrounding living organisms in all habitats of life. Microorganisms, plants and animals have developed specific mechanisms to sense such gradients. Upon perception, chemical gradients can be categorized either as favorable, like nutrients or hormones, or as disadvantageous, resulting in a clear orientation toward the gradient and avoiding strategies, respectively. Being sessile organisms, fungi use chemical gradients for their orientation in the environment. Integration of this data enables them to successfully explore nutrient sources, identify probable plant or animal hosts, and to communicate during sexual reproduction or early colony development. We have developed a 3D printed device allowing a highly standardized, rapid and low-cost investigation of chemotropic growth processes in fungi. Since the 3D printed device is placed on a microscope slide, detailed microscopic investigations and documentation of the chemotropic process is possible. Using this device, we provide evidence that germlings derived from oval conidia of the hemibiotrophic plant pathogen Colletotrichum graminicola can sense gradients of glucose and reorient their growth toward the nutrient source. We describe in detail the method establishment, probable pitfalls, and provide the original program files for 3D printing to enable broad application of the 3D device in basic, agricultural, medical, and applied fungal science.