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Ceratocystis wilt is a lethal disease of cacao, and the search for resistant genotypes may provide the best way to deal with the disease. Resistance or susceptibility behavior of some cacao genotypes when infected by Ceratocystis cacaofunesta is not yet understood. Herein, we report an LC-MS metabolomic screening analysis based on high-resolution MS to obtain comprehensive metabolic profile associated with multivariate data analysis of PLS-DA, which was effective to classify CCN-51 and TSH-1188 as resistant genotypes to C. cacaofunesta fungus, while CEPEC2002 was classified as a susceptible one. Using reversed-phase LC method, electrospray interface, and high-resolution tandem MS by the quadrupole-TOF analyzer, the typical profiles of metabolites, such as phenylpropanoids, flavonoids, lipids, alkaloids, and amino acids, were obtained. Untargeted metabolite profiles were used to construct discriminant analysis by partial least squares (PLS-DA)-derived loading plots, which placed the cacao genotypes into two major clusters related to susceptible or resistant groups. Linolenic, linoleic, oleic, stearic, arachidonic, and asiatic acids were annotated metabolites of infected, susceptible, and resistant genotypes, while methyl jasmonate, jasmonic acid, hydroxylated jasmonic acid, caffeine, and theobromine were annotated as constituents of the resistant genotypes. Trends of these typical metabolites levels revealed that CCN51 is susceptible, CEPEC2002 is moderately susceptible, and TSH1188 is resistant to C. cacaofunesta. Therefore, profiles of major metabolites as screened by LC-MS offer an efficient tool to reveal the level of resistance of cacao genotypes to C. cacaofunesta present in any farm around the world., (© 2021 Wiley-VCH GmbH.)

The overall goal of this study was to determine whether the genome of an important plant pathogen in Africa, Ceratocystis albifundus, is structured into subgenomic compartments, and if so, to establish how these compartments are distributed across the genome. For this purpose, the publicly available genome of C. albifundus was complemented with the genome sequences for four additional isolates using the Illumina HiSeq platform. In addition, a reference genome for one of the individuals was assembled using both PacBio and Illumina HiSeq technologies. Our results showed a high degree of synteny between the five genomes, although several regions lacked detectable long-range synteny. These regions were associated with the presence of accessory genes, lower genetic similarity, variation in read-map depth, as well as transposable elements and genes associated with host-pathogen interactions (e.g. effectors and CAZymes). Such patterns are regarded as hallmarks of accelerated evolution, particularly of accessory subgenomic compartments in fungal pathogens. Our findings thus showed that the genome of C. albifundus is made-up of core and accessory subgenomic compartments, which is an important step towards characterizing its pangenome. This study also highlights the value of comparative genomics for understanding mechanisms that may underly and influence the biology and evolution of pathogens., (Copyright © 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Ceratocystis wilt, caused by Ceratocystis fimbriata, is currently one of the most important disease in eucalypt plantations. Plants infected by C. fimbriata have lower volumetric growth, lower pulp yields and reduced timber values. The physiological bases of infection induced by this pathogen in eucalypt plant are not known. Therefore, this study aims to assess the physiological and metabolic changes in eucalypt clones that are resistant and susceptible to C. fimbriata. Once, we evaluated in detail their leaf gas exchange, chlorophyll a fluorescence, water potential, metabolite profiling and growth-related parameters. When inoculated, the susceptible clone displayed reduced water potential, CO 2 assimilation rate, stomatal conductance, transpiration rate, photochemical quenching coefficient, electron transport rate, and root biomass. Inoculated resistant and susceptible clones both presented higher respiration rates than healthy plants. Many compounds of primary and secondary metabolism were significantly altered after fungal infection in both clones. These results suggest that, C. fimbriata interferes in the primary and secondary metabolism of plants that may be linked to the induction of defense mechanisms and that, due to water restrictions caused by the fungus in susceptible plants, there is a partial closure of the stomata to prevent water loss and a consequent reduction in photosynthesis and the transpiration rate, which in turn, leads to a decrease in the plant's growth-related. These results combined, allowed for a better understanding of the physiological and metabolic changes following the infectious process of C. fimbriata, which limit eucalypt plant growth., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Species in the North American clade (NAC) of the Ceratocystis fimbriata complex are mostly weak pathogens that infect native tree hosts through fresh wounds. Isolations from discolored tissue of wounded Tilia americana (basswood) in Iowa and Nebraska yielded a Ceratocystis species that was similar to but distinct from isolates of C. variospora from other hosts. Sequences of 28S rDNA showed that isolates from basswood did not differ from C. variospora, but there were minor differences in ITS rDNA sequences. The DNA sequences of a portion of the Cerato-platanin gene and TEF1α showed the basswood fungus to be a unique lineage. Cross inoculations in two experiments showed that the basswood isolates and C. variospora isolates from Quercus spp. were most aggressive to their respective hosts. Isolates from basswood grew slower and were less pigmented than C. variospora isolates from Quercus spp. The basswood fungus thus is distinguished from C. variospora based on phylogenetic analyses and phenotype and is herein described as C. tiliae sp. nov., (© 2015 by The Mycological Society of America.)

Ceratocystis wilt is one of the main diseases of the cocoa crop, genetic resistance is the most efficient control strategy; therefore, the priority is to develop rapid methodologies to detect resistance sources. The study objective was to standardize an infection method to detect tolerance against Ceratocystis spp. An experiment for artificial inoculation of IMC 67 plants was established in a CRD. Two concentrations of inoculum were evaluated (3x105 and 3x106 CFU / ml) and three depths of wound to the stem (superficial: very fine cut maximum depth to the bark; middle: wound to the log; and deep: the wound reaches the medulla). The plants were inoculated by wounding the stem of approximately 2 cm in length and at 5 cm from the graft, 30 μl of the concentrations evaluated were used per plant. Plants inoculated with sterile distilled water were used as absolute control. Fifteen replicates per treatment were established. Weekly count readings and removal of dead plants were carried out. The final severity in the surviving plants was determined at 60 days after inoculation (DDI) as the length (mm) of the internal necrosis of the tissue from the root neck and along the stem and calculated as a severity ratio = total length of necrosis / total length of the plant. The data were examined by analysis of variance (ANAVA), the differences between treatments established by comparison of means using the LDS -- Fisher test (P ≥ 0.05). It was determined that the inoculum concentration 3x105 CFU / ml and the intermediate wound to the stem allow a higher qualification of tolerance in cocoa clones. Differences were established in the virulence of the isolates. [ABSTRACT FROM AUTHOR]

The article presents disease study report of Ceratocystis fimbriata causing dieback in Conocarpus lancifolius. Topics include progressive partial to complete dieback of branches, with tree mortality occurring in infected plant; and molecular confirmation of the pathogen, genomic DNA was extracted and amplified using primers for the internal transcribed spacer region.