The combination of Trichoderma virens Gl006 and B. velezensis Bs006 as a consortium has high potential to control Fusarium wilt (FW) of cape gooseberry (Physalis peruviana) caused by Fusarium oxysporum f. sp. physali (Foph). However, the interactions between these two microorganisms that influence the biocontrol activity as a consortium have not been studied. Here, we studied the interactions between Gl006 and Bs006 that keep their compatibility under in vitro and greenhouse conditions. Antagonism tests between Gl006 and Bs006 inoculated both individually and in consortium against Foph strain Map5 was carried out on several solid media. The effect of supernatant of each selected microorganism on growth, conidia germination, biofilm formation and antagonistic activity on its partner was also studied. Biocontrol activity by different combinations of cells and supernatants from both microorganisms against Fusarium wilt was evaluated under greenhouse conditions. In vitro antagonism of the consortium against Foph showed a differential response among culture media and showed compatibility among BCA under nutritional conditions close to those of the rhizosphere. The supernatant of Bs006 did not affect the antagonistic activity of Gl006 and vice versa. However, the supernatant of Bs006 promoted the biocontrol activity of Gl006 in a synergistic way under greenhouse, reducing the disease severity by 71%. These results prove the compatibility between T. virens Gl006 and B. velezensis Bs006 as a potential tool to control Fusarium wilt of cape gooseberry.

To evaluate the effect of lactic acid bacteria (LAB) on the control of Fol59 and Rs on singly infected and co-infected tomato plants and to address molecular pathways that may be involved in this interaction. To assess the development of the disease, individual infection and coinfection were stimulated in plants under controlled conditions, at two concentrations of Rs and Fol59 applied at two different moments. Additionally, the antagonistic activity of LAB against Rs and Fol59 in vitro and its biocontrol efficacy in planta were evaluated. Preliminary results indicate that inoculation with 1 × 10⁶ microconidia ml⁻¹ of Fol59 and 1 × 10⁸ cfu ml⁻¹ of Rs may be a reliable synchronous coinfection method. Of the 68 LAB strains evaluated in vitro, AC13, AC40, and AC49 had an antagonistic effect on both pathogens, with AC40 showing the highest efficacy rate after submerging the seeds in suspension and sowing them in substrate. Finally, gene expression experiments confirmed the AC40 effect on the expression of PR-1a, ERF1, and LoxA genes. The delayed appearance of symptoms and the reduced severity of the disease may be associated with the expression of PR-1a, ERF1, and LoxA genes related to salicylic acid, ethylene, and jasmonic acid pathways respectively.

The infection process of the hemibiotrophic fungus Colletotrichum lindemuthianum has been independently studied at the microscopic and genomic levels. However, the relationship between the morphological changes and the pathogenicity mechanisms of the fungus at the early stages of the infection remains uncharacterized. Therefore, this study attempts to bridge this gap by integrating microscopic and transcriptional approaches to understand the infection process of C. lindemuthianum. Fungal structures were followed by fluorescence microscopy for 120 hours. Simultaneously, the transcriptomic profile was made using RNAseq. Morphological characterization shows that appressoria, infective vesicles, and secondary hypha formation occur before 72 hours. Additionally, we assembled 38,206 transcripts with lengths between 201 and 3,548 bp. The secretome annotation revealed the expression of 1,204 CAZymes, of which 17 exhibited secretion domains and were identified as chitinases and β-1,3-glucanases, 27 were effector candidates, and 30 were transport proteins mostly associated with ABC-type. Finally, we confirmed the presence and expression of CAC1 role during the appressoria formation of Clr7. This result represents the first report of adenylate cyclase expression evaluated under three different approaches. In conclusion, C. lindemuthianum colonizes the host through different infection structures complemented with the expression of multiple enzymes, where CAC1 favors disease development.

The use of microbial consortia has become a promising alternative for the management of various diseases. In this study, 18 artificial consortia were designed, consisting of five bacteria, five fungi, and a mixture of five fungi and five bacteria; from a collection of microorganisms isolated from the rhizosphere of cape gooseberry plants grown in two soils potentially suppressive against Fusarium oxysporum. When evaluated under greenhouse conditions for their biocontrol activity on cape gooseberry plants, one consortium was selected for their high efficacy (over 90%) in the control of vascular wilt caused by F. oxysporum f. sp. physali. This was constituted by ten microorganisms, the bacteria Paenibacillus peoriae, Bacillus subtilis, Lysinibacillus sp., Bacillus simplex, and Pseudomonas chlororaphis; and the fungi Beauveria bassiana, Scopulariopsis brevicaulis, Trichoderma gamsii, Trichoderma ghanense, and Trichoderma lignicola. On the other hand, four of the consortia evaluated in the presence of the pathogen mitigated the deleterious effect produced by the pathogen on plant growth, expressing higher dry weights, both in the aerial and root parts. This work represents the first report on using these mixtures of microorganisms to control vascular wilt produced by F. oxysporum. However, further studies are needed to determine their activity in cape gooseberry fields.

Cape gooseberry ( Physalis peruviana ) is Colombia's second most exported fruit, with a market worth 37.8 million USD in 2021. Fusarium oxysporum f sp. physalis ( Foph ) is arguably the most devastating pathogen causing losses of up to 80%. Managing this disease is challenging due to pathogen resistance or the reduced efficacy of commercial fungicides and the production of resistant structures allowing pathogen survival in the soil for up to 30 years. Thus, new methods of control are necessary. Two cape gooseberry farms (organic vs. conventional) were detected free from Foph in Nariño. We hypothesize that the soil microbiome might have a suppressive effect against vascular wilt, caused by Foph . To test this, farm soils were propagated by adding 10% farm soil and 90% peat soil. Then, peat soil (control) and propagated soils were inoculated with Foph . A decrease of 65%–68% in disease incidence and a 70% in disease severity reduction was observed in seedlings grown in propagated soils compared to peat soil. We then used next‐generation sequencing to study the soil microbiome to understand the possible mechanisms for disease suppression of propagated soils. We conclude that despite the high diversity of soil microbiomes, the relative abundance of some taxa might be a more important indicator of disease suppression than the presence of specific taxa.

Cocoa phytosanitary problems in Colombia are one of the main causes of the decline in cocoa production, with losses that can reach 100% due to inadequate management. Ceratocystis wilt is a prevalent disease affecting cocoa crops in the country, with C. fimbriata identified as its causal agent. However, there are still inconsistencies at the morphological level regarding the causal species, which contradict the causal relationship of the pathogen with the disease, affecting its diagnosis. Studies based on the phenotypic and genotypic characterization of Ceratocystis species are imperative for reliable identification of the pathogen. The objective of this study was to morphologically and molecularly characterize isolates of Ceratocystis spp. obtained from symptomatic samples in the cocoa-producing regions of Colombia. Morphological characteristics were evaluated at the macro and microscopic levels. Additionally, isolates were identified at the species level through multi-locus analysis and phylogenetic characterization using the β-tubulin (βT-1), guanine nucleotide-binding protein (MS204), second largest subunit of RNA polymerase II (RPBII), and 60 S ribosomal protein L37 (FG1093) gene regions. The results revealed variations in the colony development and microscopic morphology. Molecular and phylogenetic analyses consistently classified all isolates as Ceratocystis cacaofunesta, confirming that this species is the causal agent of cocoa Ceratocystis wilt in Colombia.