Study of the secondary metabolism of phytopathogenic fungi as a source of compounds with antibiotic activity.

Eutypa lata is a phytopathogenic fungus responsible for a "Grapevine Trunk Disease" commonly called "eutypiosis" or "eutypa dieback" which affects several agricultural crops. Its secondary metabolism has been studied in order to find the main toxins that cause the symptoms of the disease, and to learn how to control its production. One of the most phytophatogenic toxins is Eutypine, a hydroxybenzaldehyde, among several acetylenic derivatives related with it. Syccaine is one of them and exhibits antimicrobial activity against Aerobacter aerogenes and a variety of Gram-positive bacteria, and few fungi. That is why, in this study, we enviosioned the study of the secondary metabolism of E. lata as a producer of natural acetylenic compounds with antimicrobial activity to give response to the worlwide problem posed by the shortage of new antibiotics development.Throught OSMAC (One Strain Many Compounds) approach, two strains of the fungus, E. lata 355 y E. lata 311, were grown using different cultivation conditions like culture media composition, aeration, type of culture flask or incubation time. The extract obtained from the extraction with ethyl acetate of the culture media, was tested against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae using the broth dilution method. Then, the extracts with antibiotical activity were purified in order to obtain pure compounds to find which compound are responsible for the antibiotical activity.The preliminary results of the research have indicated that OSMAC approach estimulates the production of compounds with antibiotic activity in some of the culture conditions tested

Genetic and molecular basis of botrydial biosynthesis: connecting cytochrome P450-encoding genes to biosynthetic intermediates

Over two hundred species of plants can be infected by the phytopathogenic fungus Botrytis cinerea under a range of different environmental conditions. In response to these, the fungus produces unique terpenoid and polyketide metabolites. Parts of the plants may be killed by the phytotoxin botrydial, enabling the fungus to feed on the dead cells. In this paper, we describe the genetic and molecular basis of botrydial biosynthesis and the function of the five genes of the genome of B. cinerea that together constitute the botrydial biosynthetic gene cluster. Genes BcBOT3 and BcBOT4, encoding two cytochrome P450 monooxygenases, were inactivated by homologous recombination and were shown to catalyze regio- and stereospecific hydroxylations at the carbons C-10 and C-4, respectively, of the presilphiperfolan-8β-ol skeleton. The null mutants, bcbot3Δ and bcbot4Δ, accumulated key intermediates in the botrydial biosynthesis enabling the complete genetic and molecular basis of the botrydial biosynthetic pathway to be established. Furthermore, the bcbot4Δ mutant overproduced a significant number of polyketides, which included, in addition to known botcinins, botrylactones and cinbotolide A, two new botrylactones and two new cinbotolides, cinbotolides B and C

Práctica 13. Montaje con biseladora automática 3_B con tracer, plantilla o lentes demo, de unas lentes esfero-cilíndricas orgánicas y/o minerales, sobre monturas de acetato y/o metal

Montaje con biseladora automática 3_B con tracer, plantilla o lentes demo, de unas lentes esfero-cilíndricas orgánicas y/o minerales, sobre monturas de acetato y/o metal

Práctica 12. Montaje con biseladora automática 3_A con tracer, plantilla o lentes demo, de unas lentes esfero-cilíndricas orgánicas y/o minerales, sobre monturas de acetato y/o metal.

Montaje con biseladora automática 3_A con tracer, plantilla o lentes demo, de unas lentes esfero-cilíndricas orgánicas y/o minerales, sobre monturas de acetato y/o metal

The veil of flor’s structure, composition and interactions in biological ageing wines

Biological ageing occurs after fermentation of the grape must and it is due to the appearance of a biofilm on the surface of the wine called "veil of flor". Yeast involved in veil formation are mainly Saccharomyces cerevisiae and they have traditionally been divided into four races according to their ability to metabolize different sugars. The growth of flor yeasts depends on different factors, such as the aerobic assimilation of the wine ethanol, since the medium is deficient in both sugars and nitrogen. Actually, flor yeast metabolism is different from wine S. cerevisiae yeast, but it hasn't been analysed yet. Thus, the aim of this work is to study the diversity of flor yeast strains and to analyse the composition and the structure of the veil of flor in Jerez-Xeres-Sherry D.O. The results of this work revealed 14 different genotypes of S. cerevisiae strains using multiplex-microsatellite PCR and these strains showed 8 different biochemical profiles using a similar procedure than traditionally. In addition, mannose and glucose were found in veil of flor complex using UHPLC-MS

Artificial Intelligence: A Promising Tool for Application in Phytopathology

Artificial intelligence (AI) is revolutionizing approaches in plant disease management and phytopathological research. This review analyzes current applications and future directions of AI in addressing evolving agricultural challenges. Plant diseases annually cause 10–16% yield losses in major crops, prompting urgent innovations. Artificial intelligence (AI) shows an aptitude for automated disease detection and diagnosis utilizing image recognition techniques, with reported accuracies exceeding 95% and surpassing human visual assessment. Forecasting models integrating weather, soil, and crop data enable preemptive interventions by predicting spatial-temporal outbreak risks weeks in advance at 81–95% precision, minimizing pesticide usage. Precision agriculture powered by AI optimizes data-driven, tailored crop protection strategies boosting resilience. Real-time monitoring leveraging AI discerns pre-symptomatic anomalies from plant and environmental data for early alerts. These applications highlight AI’s proficiency in illuminating opaque disease patterns within increasingly complex agricultural data. Machine learning techniques overcome human cognitive constraints by discovering multivariate correlations unnoticed before. AI is poised to transform in-field decision-making around disease prevention and precision management. Overall, AI constitutes a strategic innovation pathway to strengthen ecological plant health management amidst climate change, globalization, and agricultural intensification pressures. With prudent and ethical implementation, AI-enabled tools promise to enable next-generation phytopathology, enhancing crop resilience worldwide

In Vitro Analysis of the Antagonistic Biological and Chemical Interactions between the Endophyte Sordaria tomento-alba and the Phytopathogen Botrytis cinerea

Plant pathogenic infections causing substantial global food losses are a persistent challenge. This study investigates a potential biocontrol strategy against the necrotrophic fungus Botrytis cinerea using the endophytic fungus Sordaria tomento-alba isolated from Gliricidia sepium in Colombia. Today, synthetic fungicides dominate B. cinerea control, raising environmental and health concerns. S. tomento-alba exhibits notable in vitro effects, inhibiting B. cinerea growth by approximately 60% during co-culture and 50% in double disc co-culture. Additionally, it suppresses botryanes production and produces the compound heptacyclosordariolone, which has proven effective in inhibiting B. cinerea mycelial growth and spore germination in vitro. This biocontrol agent could be a potential eco-friendly alternative to replace synthetic fungicides. Our study provides insights into the chemical and biological mechanisms underpinning the antagonistic activity of S. tomento-alba, emphasizing the need for further research to understand its biosynthesis pathways and optimize its biocontrol potential. It also contributes molecular evidence of fungal interactions with implications for advanced forums in molecular studies in biology and chemistry, particularly in addressing plant pathogenic infections and promoting sustainable agriculture

Identification of polyketide synthase genes required for aspinolide biosynthesis in Trichoderma arundinaceum

https://link.springer.com/article/10.1007/s00253-022-12182-9[EN] The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T. arundinaceum. Comparative genomics identified two polyketide synthase genes (asp1 and asp2) that occur in T. arundinaceum and Aspergillus ochraceus, which also produces aspinolides. Gene deletion and biochemical analyses in T. arundinaceum indicated that both genes are required for aspinolide production: asp2 for formation of a 10-member lactone ring and asp1 for formation of a butenoyl subsituent at position 8 of the lactone ring. Gene expression and comparative genomics analyses indicated that asp1 and asp2 are located within a gene cluster that occurs in both T. arundinaceum and A. ochraceus. A survey of genome sequences representing 35 phylogenetically diverse Trichoderma species revealed that intact homologs of the cluster occurred in only two other species, which also produced aspinolides. An asp2 mutant inhibited fungal growth more than the wild type, but an asp1 mutant did not, and the greater inhibition by the asp2 mutant coincided with increased HA production. These findings indicate that asp1 and asp2 are aspinolide biosynthetic genes and that loss of either aspinolide or HA production in T. arundinaceum can be accompanied by increased production of the other metabolite(s).SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Biosynthesis of abscisic acid in fungi: identification of a sesquiterpene cyclase as the key enzyme in Botrytis cinerea

While abscisic acid (ABA) is known as a hormone produced by plants through the carotenoid pathway, a small number of phytopathogenic fungi are also able to produce this sesquiterpene but they use a dis- tinct pathway that starts with the cyclization of farnesyl diphosphate (FPP) into 2Z,4E-a-ionylidene- ethane which is then subjected to several oxidation steps. To identify the sesquiterpene cyclase (STC) responsible for the biosynthesis of ABA in fungi, we conducted a genomic approach in Botrytis cinerea. The genome of the ABA-overproducing strain ATCC58025 was fully sequenced and five STC-coding genes were identified. Among them, Bcstc5 exhibits an expression profile concomitant with ABA produc- tion. Gene inactivation, complementation and chemical analysis demonstrated that BcStc5/BcAba5 is the key enzyme responsible for the key step of ABA biosynthesis in fungi. Unlike what is observed for most of the fungal secondary metabolism genes the key enzyme-coding gene Bcstc5/Bcaba5 is not clustered with the other biosynthetic genes, i.e. Bcaba1 to Bcaba4 that are responsible for the oxida- tive transformation of 2Z,4E-a-ionylideneethane. Finally, our study revealed that the presence of the Bcaba genes among Botrytis species is rare and that the majority of them do not possess the ability to pro- duce ABA

Botrydial and botcinins produced by Botrytis cinerea regulate the expression of Trichoderma arundinaceum genes involved in trichothecene biosynthesis

Trichoderma arundinaceum IBT 40837 (Ta37) and Botrytis cinerea produce the sesquiterpenes harzianum A (HA) and botrydial (BOT), respectively, and also the polyketides aspinolides and botcinins (Botcs), respectively. We analysed the role of BOT and Botcs in the Ta37-B. cinerea interaction, including the transcriptomic changes in the genes involved in HA (tri) and ergosterol biosynthesis, as well as changes in the level of HA and squalene-ergosterol. We found that, when confronted with B. cinerea, the tri biosynthetic genes were up-regulated in all dual cultures analysed, but at higher levels when Ta37 was confronted with the BOT non-producer mutant bcbot2Δ. The production of HA was also higher in the interaction area with this mutant. In Ta37-bcbot2Δ confrontation experiments, the expression of the hmgR gene, encoding the 3-hydroxy-3-methylglutaryl coenzyme A reductase, which is the first enzyme of the terpene biosynthetic pathway, was also up-regulated, resulting in an increase in squalene production compared with the confrontation with B. cinerea B05.10. Botcs had an up-regulatory effect on the tri biosynthetic genes, with BotcA having a stronger effect than BotcB. The results indicate that the interaction between Ta37 and B. cinerea exerts a stimulatory effect on the expression of the tri biosynthetic genes, which, in the interaction zone, can be attenuated by BOT produced by B. cinerea B05.10. The present work provides evidence for a metabolic dialogue between T. arundinaceum and B. cinerea that is mediated by sesquiterpenes and polyketides, and that affects the outcome of the interaction of these fungi with each other and their environmentSIFunding was obtained from the Junta de Castilla y Leon (SA260A11-2,LE125A12-2 and LE228U14) and Spanish Government grants MICINN-AGL2009-13431-C02-02, MINECO-AGL2012-40041-C02-01, AGL2012-40041-C02-02 and AGL2012-39798-C02-01. MGM and II-B were granted fellowships from the Spanish Ministry of Science and Innovation(AP2007-02835, BES-2013-063411