Asymmetric preparation of antifungal 1-(4 -chlorophenyl)-1-cyclopropyl methanol and 1-(4 -chlorophenyl)-2-phenylethanol. Study of the detoxification mechanism by Botrytis cinerea

Chiral alcohols are important as bioactive compounds or as precursors to such molecules. On the basis of the different antifungal properties of the enantiopure alcohol derivatives of 4-chlorophenyl cyclopropyl ketone and benzyl 4-chlorophenyl ketone, their enantioselective synthesis by chemical and biocatalytic methods was studied. The detoxification pathways by the phytopathogen fungus Botrytis cinerea are reported

Cladobotryum mycophilum as Potential Biocontrol Agent

A study was conducted to explore the efficacy of potential biocontrol agent Cladobotryum mycophilum against different phytopathogenic fungi. The growth rates of 24 isolates of C. mycophilum were determined, and their antagonistic activity was analysed in vitro and in vivo against Botrytis cinerea, Fusarium oxysporum f. sp. radicis-lycopersici, Fusarium oxysporum f.sp. cucumerinum, Fusarium solani, Phytophthora parasitica, Phytophthora capsici, Pythium aphanidermatum and Mycosphaerella melonis. Most isolates grow rapidly, reaching the opposite end of the Petri dish within 72–96 h. Under dual-culture assays, C. mycophilum showed antagonistic activity in vitro against all phytopathogenic fungi tested, with mycelial growth inhibition ranging from 30 to 90% against all the different phytopathogens tested. Similarly, of all the selected isolates, CL60A, CL17A and CL18A significantly (p < 0.05) reduced the disease incidence and severity in the plant assays compared to the controls for the different pathosystems studied. Based on these results, we conclude that C. mycophilum can be considered as a potential biological control agent in agriculture. This is the first study of Cladobotryum mycophilum as a biological control agent for different diseases caused by highly relevant phytopathogens in horticultur

Plant Growth Promotion and Biocontrol of Pythium ultimum by Saline Tolerant Trichoderma Isolates under Salinity Stress

This present study evaluates three isolates of Trichoderma as plant growth promoting or biological control agents: Trichoderma aggressivum f. sp. europaeum, Trichoderma saturnisporum, and the marine isolate obtained from Posidonia oceanica, Trichoderma longibrachiatum. The purpose is to contribute to an overall reduction in pesticide residues in the fruit and the environment and to a decrease in chemical fertilizers, the excess of which aggravates one of the most serious abiotic stresses, salinity. The tolerance of the different isolates to increasing concentrations of sodium chloride was evaluated in vitro, as well as their antagonistic capacity against Pythium ultimum. The plant growth promoting capacity and effects of Trichoderma strains on the severity of P. ultimum on melon seedlings under saline conditions were also analysed. The results reveal that the three isolates of Trichoderma, regardless of their origin, alleviate the stress produced by salinity, resulting in larger plants with an air-dry weight percentage above 80% in saline stress conditions for T. longibrachiatum, or an increase in root-dry weight close to 50% when T. aggressivum f. sp. europaeum was applied. Likewise, the three isolates showed antagonistic activity against P. ultimum, reducing the incidence of the disease, with the highest response found for T. longibrachiatum. Biological control of P. ultimum by T. aggressivum f. sp. europaeum and T. saturnisporum is reported for the first time, reducing disease severity by 62.96% and 51.85%, respectively. This is the first description of T. aggressivum f. sp. europaeum as a biological control agent and growth promoter. The application of these isolates can be of enormous benefit to horticultural crops, in both seedbeds and greenhouses

Comment on 'Evolutionary transitions between beneficial and phytopathogenic Rhodococcus challenge disease management'

I would like to report significant issues of concern regarding this paper (Savory et al., 2017)

Ga and Gß Proteins Regulate the Cyclic AMP Pathway That Is Required for Development and Pathogenicity of the Phytopathogen Mycosphaerella graminicola

We identified and functionally characterized genes encoding three G alpha proteins and one G beta protein in the dimorphic fungal wheat pathogen Mycosphaerella graminicola, which we designated MgGpa1, MgGpa2, MgGpa3, and MgGpb1, respectively. Sequence comparisons and phylogenetic analyses showed that MgGPA1 and MgGPA3 are most related to the mammalian G alpha(i) and G alpha(s) families, respectively, whereas MgGPA2 is not related to either of these families. On potato dextrose agar (PDA) and in yeast glucose broth (YGB), MgGpa1 mutants produced significantly longer spores than those of the wild type (WT), and these developed into unique fluffy mycelia in the latter medium, indicating that this gene negatively controls filamentation. MgGpa3 mutants showed more pronounced yeast-like growth accompanied with hampered filamentation and secreted a dark-brown pigment into YGB. Germ tubes emerging from spores of MgGpb1 mutants were wavy on water agar and showed a nested type of growth on PDA that was due to hampered filamentation, numerous cell fusions, and increased anastomosis. Intracellular cyclic AMP (cAMP) levels of MgGpb1 and MgGpa3 mutants were decreased, indicating that both genes positively regulate the cAMP pathway, which was confirmed because the WT phenotype was restored by adding cAMP to these mutant cultures. The cAMP levels in MgGpa1 mutants and the WT were not significantly different, suggesting that this gene might be dispensable for cAMP regulation. In planta assays showed that mutants of MgGpa1, MgGpa3, and MgGpb1 are strongly reduced in pathogenicity. We concluded that the heterotrimeric G proteins encoded by MgGpa3 and MgGpb1 regulate the cAMP pathway that is required for development and pathogenicity in M. graminicola

The dual nature of trehalose in citrus canker disease: A virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant's metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant's resources after infection, but on the other hand, it is a tell-tale sign of the pathogen's presence that triggers the plant to defend itself against infection.Fil: Piazza, Ainelén Melanie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Zimaro, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Garavaglia, Betiana Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Ficarra, Florencia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Thomas, Ludivine. King Abdullah University of Science and Technology; Arabia SauditaFil: Marondedze, Claudius. King Abdullah University of Science and Technology; Arabia SauditaFil: Feil, Regina. Max Planck Institute of Molecular Plant Physiology; AlemaniaFil: Lunn, John E.. Max Planck Institute of Molecular Plant Physiology; AlemaniaFil: Gehring, Chris. King Abdullah University of Science and Technology; Arabia SauditaFil: Ottado, Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gottig Schor, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin

Antagonistic capacities of Trichoderma species and their mass multiplication with agricultural wastes

El objetivo de esta investigación fue aislar y caracterizar cepas de Trichoderma nativas de Misiones (Argentina)explorando sus capacidades antagónicas y su multiplicación masiva utilizando diferentes residuos agroindustriales.Quince cepas nativas de Trichoderma spp. fueron aisladas de muestras de suelo. Estos aislamientos secaracterizaron mediante observaciones morfológicas y moleculares basados en secuencias de ADN de la regiónespaciadora transcrita interna del ADNr. Las cepas de Trichoderma spp. fueron identificadas como T. koningiopsis,T. harzianum, T. pleuroticola y T. brevicompactum. Estas cepas mostraron actividades antagónicas in vitro contraAlternaria sp., Fusarium sp. y Botrytis sp.. T. koningiopsis LBM 090, LBM 091, LBM 092 y LBM 098, T. pleuroticolaLBM 097 y T. harzianum LBM 096 presentaron una inhibición del crecimiento micelial mayor del 50% y un índicede antagonismo entre 3 y 4 contra los fitopatógenos ensayados. La cáscara de arroz y el pulido del arroz fueronlas combinaciones más adecuadas para la multiplicación de T. harzianum LBM 096.The aim of this research was to isolate and characterize Trichoderma native strains from Misiones (Argentina) exploring their antagonistic capacities to phytopatogens fungi and their mass multiplication using different agricultural wastes. Fifteen native strains of Trichoderma spp. were isolated from soil samples. These isolates were characterized via morphological observations and molecular phylogenetic analysis based on DNA sequences of the rDNA internal transcribed spacer region. The Trichoderma native strains were identified as T. koningiopsis, T. harzianum, T. pleuroticola and T. brevicompactum. All strains showed antagonistic activities in vitro against Alternaria sp., Fusarium sp. and Botrytis sp. T. koningiopsis LBM 090, LBM 091, LBM 092, and LBM 098 strains, T. pleuroticola LBM 097 and T. harzianum LBM 096 presented radial mycelial growth inhibition higher than 50% and antagonism index between 3 and 4 against the phytopathogens assayed. Among the different substrate sources evaluated, rice husk and rice polishing were the most suitable combination for mass multiplication of T. harzianum LBM 096.Fil: Sadañoski, Marcela Alejandra. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Gutierrez Brower, Gimena. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Castrillo, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Lopez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Ojeda, Paola. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Zapata, Pedro Dario. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Villalba, Laura Lidia. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Otegui, Monica Beatriz. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentin

Biocontrol of root and crown rot in tomatoes under greenhouse conditions using Trichoderma harzianum and Paenibacillus lentimorbus. Additional effect of solarization

Indexación: ScieloTrichoderma harzianum 650 (Th650) and Paenebacillus lentimorbus 629 (Pl629) selected earlier for their ability to control Rhizoctonia solani, Fusarium solani and F. oxysporum in vitro, were applied alone or combined with solarization (summer assay) and/or with methyl bromide (MeBr) (summer and winter assays) to a soil with a high inoculum level, for the control of tomato root rot caused by the complex F. oxysporum f. sp. lycopersici - Pyrenochaeta lycopersici - Rhizoctonia solani. Evaluations were also performed independently for root damage caused by P. lycopersici, and also for R. solani in the summer assay. MeBr decreased tomato root damage caused by the complex from 88.7% to 21.2% and from 78.4% to 35.7% in the summer and in the winter assay, respectively. None of the bio-controllers could replace MeBr in the winter assay, but Th650 and Pl629 reduced root damage caused by this complex in the summer assay. Treatments with bio-controllers were improved by their combination with solarization in this season. Independent evaluations showed that the positive control of Th650 towards R. solani and the lack of effect on P. lycopersici correlates well with the endochitinase pattern expressed by Th650 in response to these phytopathogens. Root damage caused by R. solani can be controlled at a similar level as it does MeBr in summer assays, thus representing an alternative to the use of this chemical fungicide for the control of this phytopathogen.Financial support: Fondecyt 1990785

Evaluation of trichoderma isolates as potential biological control agent against soybean charcoal rot disease caused by Macrophomina phaseolina

Macrophomina phaseolina (Tassi) Goid remains the prevailing causal agent of charcoal rot disease that significantly suppresses the yield of a variety of oilseed crops. Its wide host range and ability to survive under arid conditions, coupled with the ineffective use of fungicides against it, have spurred scientific endeavours for alternative avenues to control this phytopathogen. Hence, the present study aimed to provide empirical evidence of the efficacy of three fungal isolates (T2, T10 and T12) of Trichoderma harzianum as biological control agents against charcoal rot in soybean (Glycine max L.). The results of the in vitro studies revealed that all three fungal isolates significantly inhibited the growth of M. phaseolina phytopathogen, with T12 showing considerably higher inhibition effect than T2 and T10 isolates. T12 inhibited the growth of M. phaseolina in the dual culture (72.31%) and volatile production (63.36%) assays, and the hyperparasitism test indicated cell lysis following the interactions with T12 mycelia. T12 isolate was mostly effective in field experiments, observable in the attained minimum plant disease indices both in the soil incorporation (11.98%) and seed inoculation (5.55%) treatments, in comparison to isolates T2 and T10. Moreover, the stem and root lengths, as well as the seed weight, were considerably increased, as compared to the control. Hence, the findings reported in the present study supported the applicability of T12 isolate as possible alternative to fungicides for the control of charcoal rot in soybean