Tolerance of dark septate endophytic fungi (DSE) to 1 agrochemicals in vitro / Tolerancia de hongos endofíticos septados oscuros a agroquímicos in vitro

Abstract Dark septate endophytes (DSE) are a heterogeneous group of fungi, mostly belonging to the Phylum Ascomycota, that are involved in a mutualistic symbiosis with plant roots. The aim of this study is to evaluate the behavior of two strains of DSE isolated from wheat roots of two cropping areas in the province of Buenos Aires, Argentina, against some agrochemicals. Of all the isolates obtained, two strains were identified as Alternaria alternata and Cochliobolus sp. These DSE were found to be tolerant to glyphosate, carbendazim and cypermethrin when evaluated at the recommended agronomic dose (AD), 2 AD and, in some cases, 10 AD. This work contributes to the study of the biology of this group of fungi and their tolerance in the presence of xenobiotics widely used in agriculture.© 2019 Asociaci´on Argentina de Microbiolog´ıa. Published by Elsevier Espa˜na, S.L.U. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/bync-nd/4.0/).

Resumen Los endófitos septados oscuros (DSE) son un grupo heterogéneo de hongos que participan de una simbiosis mutualista con raíces de plantas, perteneciendo principalmente al Phylum Ascomycota. El objetivo de este estudio fue aislar DSE de raíces de trigo proveniente de dos áreas de cultivo de la provincia de Buenos Aires y evaluar el comportamiento de dos cepas de DSE aisladas de raíces de trigo frente a algunos agroquímicos en dos áreas de cultivo de la provincia de Buenos Aires. De todos los aislamientos obtenidos se seleccionaron dos cepas que se identificaron como Alternaria alternata y Cochliobolus sp. Se encontró que estos DSE son tolerantes al glifosato, el carbendazim y la cipermetrina, evaluados a las dosis agronómicas recomendadas (AD), a 2x AD y, en algunos casos, a 10x AD. Este trabajo contribuye al conocimiento de la biología de este grupo de hongos y su tolerancia a xenobióticos ampliamente utilizados en la agricultura.

Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety

In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i-6m and 8f-8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive.

Antagonistic potential of fluorescent pseudomonads and control of charcoal rot of chickpea caused by Macrophomina phaseolina.

The effectiveness of plant growth promoting rhizobacteria especially Pseudomonas fluorescens isolates were tested against charcoal rot of chickpea both in green house as well as in field conditions. Most of the isolates reduced charcoal rot disease and promoted plant growth in green house. A marked increase in shoot and root length was observed in P. fluorescens treated plants. Among all the P. fluorescens isolates Pf4-99, was found most effective in the improvement of chickpea crop in green house as well as in field. Pf4-99 effectively promoted plant growth and produced indole acetic acid in culture medium. This isolate also inhibited the mycelial growth of the M. phaseolina under in vitro conditions and reduced the disease severity Potential isolate (Pf4-99) also significantly increased the biomass of the chickpea plants, shoot length, root length and protein content of the chickpea seeds. A part from these, the total number of seeds per plant and their weight were also enhanced. The colonization of Pf4-99 reduced the incidence of seed mycoflora by which indirectly enhanced the seed germination and vigour index of seedlings. The observations revealed that isolate Pf4-99 is quite effective to reduce the charcoal rot disease both in field and greenhouse, and also increases seed yields significantly Therefore, this isolate appears to be an efficient biocontrol agent against charcoal rot disease as well as yield increasing rhizobacterium.

Custo adaptativo associado à resistência de Aphis gossypii Glover (Hemiptera: Aphididae) ao inseticida carbosulfam / Fitness cost associated with carbosulfan resistance in Aphis gossypii Glover (Hemiptera: Aphididae)

Com o objetivo de prover subsídios a um programa de manejo de resistência de Aphis gossypii Glover ao carbosulfam, foram avaliados os possíveis custos adaptativos associados a essa resistência em condições laboratoriais. Para tanto, avaliou-se a estabilidade da resistência ao carbosulfam em populações de A. gossypii com diferentes freqüências iniciais de resistência e compararam-se parâmetros biológicos das linhagens suscetível e resistente ao inseticida. A estabilidade da resistência foi avaliada a partir de populações com freqüências iniciais de 20, 50 e 80 por cento de pulgões resistentes ao carbosulfam. A suscetibilidade ao carbosulfam foi estimada mensalmente durante seis meses, utilizando-se de concentração diagnóstica de 32 ppm. A biologia das linhagens suscetível e resistente foi avaliada em plantas de algodão mantidas em condições climáticas controladas. A resistência ao carbosulfam foi instável, ou seja, a suscetibilidade ao inseticida aumentou significativamente em diferentes populações de A. gossypii na ausência de pressão seletiva. Comparações de parâmetros biológicos entre as linhagens suscetível e resistente ao carbosulfam mostraram que há custo adaptativo associado à resistência. A linhagem resistente apresentou menor fecundidade, menor período reprodutivo e menor longevidade do que a linhagem suscetível. A taxa líquida de reprodução (Ro) de 14,04 e 43,18 vezes e razão finita de aumento (lambda) de 1,25 e 1,30 fêmeas/fêmea/dia para as linhagens resistente e suscetível respectivamente. Portanto, a instabilidade da resistência de A. gossypii ao carbosulfam pode ser explorada em programas de manejo da resistência.

Interactive effects of imidacloprid, profenofos and carbosulfan at low concentrations on homeostasis and haematological indices in male albino rats

Toxicity data with single pesticides to test animals are far more abundant than with mixtures [Flipo et al., 1992]. Consequently, these data cannot be used directly to predict the effect of pesticide combinations. Three pesticides; imidacloprid, profenofos and carbosulfan, administered to rats per OS at low level dose equal 1/30 LD50 for each insecticide, which represent 111, 70 and 43 ppm, respectively on homeostasis status and haematological indices [El-Kashory and El-Said, 2001], were selected to explore their combined action of subchronic exposure studies for 90 days in adult male albino rats. Homeostasis-related parameters such as; aldosterone [Ald.], sodium ions [Na+], potassium ions [K+], total chloride ions [T.Cl-] levels, pH value and haematological indices were examined in rats after an administration with different insecticide combinations. Moreover, after withdrawal the pesticide combinations for 30 days, as a recovery period, the above mentioned parameters were evaluated, in comparison with the control group. Results showed that, pesticide combination imidacloprid/profenofos [I + P] induced significant decrease in Na+ and T.Cl- ions levels and significant increase in pH value. While, it did not alter both Ald. and K+ ions levels. Combination imidacloprid/carbosulfan [I + C] increased significantly Ald., T.Cl- ions levels and pH values. On the contrary, it reduced Na+ and K+ ions levels significantly. Combination of profenofos/carbosulfan [P + C] decreased Ald. and Na+ significantly, while, K+ and T.Cl- level and pH value did not alter. In addition, tri-combination imidacloprid/ profenofos/carbosulfan [I + P + C] increased Na+ and T.Cl- ions level and pH value; while, a marked decline in Na+ ions level was occurred, as well as, no appreciable changes in K+ ion levels were observed. The combinations of I + P and I + C caused erythropenia [reduced RBC mass] associated with a significant decrease in PCV in I + C-treated rats. While, di-combinations P + C, I + P and I + P + C tri-combinations increased markedly of PCV and MCV. However, leukocytosis [elevated WBCS count] was observed in I + P + C-treated rats. After the pesticides combination withdrawal, changes in some parameters returned to the normal values, in comparison with the control group; while, the others still altered. Moreover, some parameters did not exhibit any changes unless after the stop of the treatment. In conclusion, this study supports the notion that; an interactions effects of pesticide combinations may be consider as contributor factor enhance their side effects

Inhibition of endocytotic functions in Dictyostelium discoideum treated with a carbamate pesticide.

Administration of a carbamate pesticide carbaryl (1-Naphthyl-N-methyl carbamate) at a concentration of 60 and 100 ppm greatly inhibits the endocytotic functions during growth of the cellular slime mold D. discoideum. The ingestion of fluorescien isothiocynate (FITC) labeled E. coli is reduced between 30 and 40% in the treated cells as compared to controls. Similarly, the uptake of FITC-labeled dextran, which has been used as fluid-phase marker for pinocytosis also show 40-50% inhibition in the treated cells. 3H-leucine uptake and incorporation are also inhibited in the treated cells. SDS-PAGE analysis of cytoskeletal proteins shows a higher actin association with the membrane of treated cells. The results demonstrate the detrimental effects of Carbamate on the soil microbe even at a very low concentration and the efficacy of the slime mold cells as a biosensor for the carbamate-induced cytotoxicity.

Histochemical studies on the effect of propoxur on yolk synthesis in the ovarioles of the blow fly, chrysomyia albiceps [Wiedemann] [diptera: calliphoridae]

The effect of the carbamate insecticide, propoxur, on yolk synthesis in the ovarioles of the blow fly, Chrysomyia albiceps [Wiedemann] was studied. Histochemical studies showed that DNA, RNA, protein and lipid synthesis in propoxur-treated ovarioles decreased as compared with that in non-treated ovarioles, with some deteriorations in the chromatin in the nuclei of some nurse cells. On the other hand, the synthesis of carbohydrate is more or less not affected

Influence of pretreatment of carbamates on dynamic pulmonary mechanics in rats exposed to sarin aerosols.

The effect of pretreatment of two carbamates, pyridostigmine and physostigmine on dynamic pulmonary mechanics has been studied in rats exposed to sarin aerosols. Sign-free dose of pyridostigmine (0.075 mg/kg, i.m.) or physostigmine (0.1 mg/kg, i.m.) did not significantly alter the parameters of the dynamic pulmonary mechanics 20 min after treatment. However, sarin (51.2 mg/m3, for 15 min) depressed the respiratory rate, air flow and minute volume and enhanced the transthoracic pressure and tidal volume. Pretreatment with carbamates 20 min prior to sarin exposure significantly modified or counteracted the above induced changes. It is concluded that the protective effect of carbamates is mainly due to the correction of respiratory changes caused by sarin aerosols in rats.

Alterations in metabolic activity of Cysticercus fasciolaris on some anthelmintic treatments.

Effect of candidate compounds 81-470 i.e. methyl [5[4-(2-pyridinyl)-1-piperazinyl]carbonyl]-1H-benzimidazole-2-yl]- carbamate and 86-162 i.e. methyl-5(6)-(alpha-hydroxyphenyl methyl) benzimidazole-2-carbamate along with reference drugs mebendazole and praziquantel on energy metabolism of C. fasciolaris recovered from rats treated with single dose of 500 mg/kg, ip was investigated. All the drugs significantly lowered the rate of uptake of glucose and alanine by the parasite. Suppression in the formation of lactate, the major end-product, was also noticed. Nonetheless the ratio of lactate produced versus the substrates consumed was not substantially affected. The recovered cysticerci also possessed less glycogen and ATP compared to the normal parasites. Although the effects exerted by the drugs were of the identical nature, they significantly differed in the magnitude of their action. Mebendazole followed by praziquantel maximally affected all the above metabolic activities while 86-162 proved to be the weakest in action. The results suggest that the examined drugs exert their chemotherapeutic activity by interfering with uptake of glucose and alanine but do not significantly alter their catabolism.

Effects of carbamates on the hemodynamic parameterns of rats treated or not with (alpha) - Pyridylaldoxime methylsulfomethylate (P2S)

O objetivo da presente investigaçäo foi determinar os efeitos de doses tóxicas de agentes anticolinesterasicos carbamatos, fisostigmina e carbaril, na pressäo arterial e freqüência cardíaca de ratos, bem como a açäo protetora do reativador de colinesterase, a pralidoxima, contra estes efeitos. A acetilcolina injetada intravenosamente, em ratos, causou uma imediata queda dose-dependente na Pressäo Arterial Média (PAM), seguida por um aumento na PAM que apresentava duraçäo maior que a queda. Houve também uma queda na Freqüência Cardíaca (F.C). Injeçäo intravenosa de carbaril em rato normal causou uma queda na PAM dentro de 5 segundos, seguida pelo aumento significante na mesma em relaçäo ao valor do controle, 5 minutos após a injeçäo Carbaril näo provocou nenhum efeito na F.C. Quando o carbaril foi precedido pela injeçäo de pralidoxima, as alteraçöes na PAM foram similares àquelas observadas após a injeçäo de carbaril isoladamente, porém a F.C. diminuiu de maneira significante nos grupos que receberam doses maiores. Fisostigma injetada intravenosamente em ratos normais näo apresentou efeito imediato (5 segundos) na PAM, porém ocorreu um aumento significante na PAM 5 minutos após a injeçäo. Nenhuma alteraçäo significante ocorreu na F.C. Em animais previamente tratados com pralicoxima, a fisostigmina causou uma queda imediata na PAM que foi seguida por um aumento significante em relaçäo ao controle, 5 minutos após a injeçäo. Uma queda na F.C. também ocorreu. Administraçäo prévia de pralitoxima potenciou os efeitos cardiovasculares causados pela fisostigmina, porém näo os efeitos do carbaril.

Estudios del efecto anticolinesterásico del ditiocarbamato 43GVO40 en ratones, ratas y perros / Study of the anticholinesterasic effects of dithiocarbamate 43GVO40 in mice, rats and dogs

Se realiza un estudio sobre los efectos anticolinesterásicos del ditiocarbamato 43GVO40 en ratones, ratas y perros, por estar determinado que los carbamatos ejercen una acción directa sobre los receptores colinérgicos y por ser criterio utilizable para la evaluación de la capacidad neurotóxica de un compuesto el análisis de su posible influencia sobre los sistemas de inactivación de los neurotransmisores. Se hacen las determinaciones de actividad colinesterásica en sangre total y en suero y se obtienen como resultado que este ditiocarbamato posee un bajo poder anticolinesterásico, que no explica las reacciones neurotóxicas que se presentan al administrar dicha droga en dosis letales

Effects of methyl [5 [[4-(2-pyridinyl)-1-piperazinyl]carbonyl]-1H-benzimidazol-2-yl] carbamate on energy metabolism of Ancylostoma ceylanicum and Nippostrongylus brasiliensis.

Effects of methyl [5[[4-(2-pyridinyl)-1-piperazinyl] carbonyl] 1H-benzimidazol-2-yl] carbamate (CDRI Comp. 81-470) and mebendazole on the energy metabolism of A. ceylanicum and N. brasiliensis were compared. At 10 and 50 microM concentration both compounds inhibited glucose uptake and its conversion into metabolic endproducts. The shift towards the increased production of lactic acid appeared to be the result of inhibition of PEP carboxykinase and increase in LDH activity. The compounds also caused significant inhibition of ATP production in mitochondria.