Exogenous application of salicylic acid to control coffee rust

The exogenous application of salicylic acid can induce plant resistance against pathogens. However, little is known about the potential uses of this bioregulator for controlling coffee diseases. In this study, we assessed the effect of applying salicylic acid (SA – 150 mg L-1) on the management of coffee rust (Hemileia vastatrix) in a 7-year-old coffee plantation with low crop load (651.6 kg ha-1 in 2017). For comparison, plants were sprayed with protectant fungicide (copper hydroxide – CH) and standard fungicides (SF) used by local farmers (boscalid, pyraclostrobin + epoxiconazole, and copper hydroxide). Non-treated plants were included as a negative control. Five monthly applications were performed from November 2016 to March 2017. Rust incidence and severity, defoliation, and growth of plagiotropic branches were evaluated monthly. The activity of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and total proteins was assessed one day after the first, third, and fifth product applications. Compared to untreated plants, SA reduced the severity and incidence of rust from 36.3 to 54.7%, while CH and SF reduced disease from 31.8 to 54.6% and from 83.8 to 88%, respectively. SA reduced defoliation by 54.1%. SA increased the concentration of CAT, APX, and SOD after the first application. However, this effect was not observed after subsequent applications. Foliar application of SA reduces the severity and incidence of coffee rust and defoliation in plants with a low crop load.

Effect of Salicylic Acid, 2,4-D and 2i-P on the Production of Secondary Metabolites in Garcinia brasiliensis Mart. Callus

Abstract The aim of this work was to evaluate the effect of Salicylic acid, 2,4-D and 2-iP on the production of total phenolic and flavonoids as well in the levels of fukugetin and 7-epiclusianone in callus of Garcinia brasiliensis zygotic embryos. For this, Bacupari callus were exposed to different concentrations (0.0; 0.1; 1; 10; 100 µM) of Salicylic acid (SA) in the presence or in the absence of 72 μM 2-iP and 28.73 μM 2,4-D. The highest concentration of total phenolic occurred in the treatment with 100 μM SA in callus subcultured in the absence of 2,4-D and 2-iP, and with 10 μM SA in callus subcultured in the presence of these regulators. Concerning flavonoids, 2,4-D and 2-iP supplementation without the presence of the SA was sufficient for the highest levels. Additionally, it was possible to identify the fukugetin and 7-epiclusianone. However, the variation in the levels was very high, especially for the fukugetin. Therefore, in most treatments, there was no statistically difference. Except for the treatment with 10 μM SA + 2,4-D and 2-iP, where there was a significant increase in 7-epiclusianone.

Yanomamos: ingestión de sal e hipertensión arterial / Yanomamos: salt intake and arterial hypertension

La nación yanomama es un grupo indigena aislado y autosuficiente que reside en la selva lluviosa al sur de Venezuela y norte de Brasil que ha logrado vivir en armonia con su ambiente y que ha mostrado ancestral respecto a la naturaleza sin producir basura ni contaminación. Deparam la sal que necesitan de un àrbol de la misma región llamado Tavarí. El Estudio Intersalt es una investigación observacional que ha demostrado una asociación entre la presión arterial y el consumo de sal de la dieta a través de la medición de su excreción urinaria. Los hallazgos encontrados en este grupo poblacional fueron extraordinarios: Niveles de presión arterial muy bajos que no se incrementaron con la edad, niveles de colesterol muy reducidos, ausencia de alcoholismo u obesidad. Constituyen un experimento de la naturaleza digno de seguir; desafortunadamente el mundo occidental ha tenido un impacto negativo en sus vidas y cultura

The nation yanomami is an isolated and self-sufficient indigenous group who reside in the rainy forest to the south of Venezuela and north of Brazil that has managed to live in harmony with its atmosphere and that has shown ancestral respect to the nature without producing any sweepings or contamination. They obtain the salt that needs from a local tree of called Tavarí. The Intersalt Study is an observational investigation that has demostrated an association between the arterial pressure and the consumption of salt of the diet through the measurement of its urinary excretion. The findings found in this population group were extraordinary: very low levels of pressure arterial that are not increased with the age, cholesterol levels very reduced, absence of alcoholism or obesity, very low sodium excretion. They constitute an experiment of the nature worthy to follow; unfortunately western world had much of a negative impact on their lives or culture

[Measurement of salicylic acid in poplar's bark [P. deltoides and P. euramerican] by high performance liquid chromatography [HPLC]]

The family salicaceae included salix and populus species. This family especially salix alba is very important in ancient medicinal. Recognition and investigation on other species in this family can help to development of herbal medical in country. This study was done to measuring of salicylic acid in Populus deltoides and Populus euramerican. After collection and drying of barks, extraction was done according to TAPPI standard [T204 om-88] by using acetone, ethanol and water solutions. Measuring of Salicylic acid was done by HPLC [High Performance Liquid Chromatography]. The extractive materials yield of populus deltoides and populus euramerican's bark were obtained 12.2 and 17.7% respectively base on dry weight of bark. HPLC analysis shows that there are 32 compounds in water extractive materials which amount of two compounds are more than others. According to retention time one of two compounds is Salicylic acid. The Salicylic acid values in populus deltoides and euramerican bark extractive materials are 14.7 and 19.5 ppm respectively. Generally, this research show that populus species contains Salicylic acid which is lower than Salix alba. The amount of Salicylic acid in populus euramerican is more than populus deltoids. Hydrophobic compounds in populus euramerican are twice than populus deltoides. There is no significant difference between hydrophilic compounds of two species

Determination of benzoic acid and salicylic acid in commercial benzoic and salicylic acids ointments by spectrophotometric method

Commercial benzoic acid and salicylic acid ointments have been analyzed for benzoic acid and salicylic acid content by using a spectrophotometric method. Since benzoic acid and salicylic acid exhibit overlapping spectra, absorbance measurements are made at two wavelengths, i.e. 271 nm and 303 nm in ethanol [96%v/v] for simultaneous determination of the two compounds. The method is direct and involves only one step of absorbance measurement in the assay. The precision of the method, based on the analysis of synthetic mixtures of the two compounds, is within 2%. The recoveries of benzoic acid and salicylic acid in the ointments range from 99.9 to 100.6% and 99.5 to 101.3%, respectively and are comparable with those of the USP method [99.8 to 100.5% and 100.2 to 101.7%, respectively]. The proposed method is simple, rapid, precise and convenient for the assay of benzoic acid and salicylic acid in commercial preparations

Control of brown spot pathogen of rice (Bipolaris oryzae) using some phenolic antioxidants / Controle da macha-parda do arroz (Bipolaris oryzae) pelo emprego de antioxidantes fenólicos

Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone). The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS) and disease incidence (DI) on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves and in the total carbohydrate and protein contents of the yielded grains.

Bipolaris oryzae é o agente causador da doença mancha-parda do arroz e é responsável por significativas perdas econômicas. Três antioxidantes fenólicos (ácido salicílico, ácido benzóico e hidroquinona) foram avaliados para o controle dessa doença do arroz. A atividade antifúngica destes compostos foi avaliada in vitro contra B. oryzae em diferentes concentrações e a eficiência de sua aplicação exógena no controle da mancha-parda foi avaliada em condições de campo. Nos ensaios in vitro, os ácidos benzóico e salicílico a 9 mM inibiram completamente a multiplicação de B. oryzae. Em condições de campo, a aspersão de ácido benzóico a 20 mM causou uma redução significativa na gravidade e incidência da doença na folhas da planta, além de aumentar significativamente o rendimento dos grãos e seus componentes. Algumas respostas bioquímicas foram também observadas, verificando-se que a aplicação do tratamento prévio causou um aumento significativo nos pigmentos fotossintéticos totais (clorofila a e b e carotenóides) nas folhas e no conteúdo de carboidratos e proteínas nos grãos.

Salicylic acid degradation from aqueous solutions using Pseudomonas fluorescens HK44: parameters studies and application tools

The optimal conditions for salicylic acid biodegradation by Pseudomonas fluorescens HK44 were determined in this study with the intention to create a microbial sensor. Kinetic experiments permitted a definition of 60 and 30min the time needed to achieve the maximum degradation of salicylic acid presented in a medium with and without yeast extract, respectively. The degradation in medium without yeast extract and the quantification by spectrophotometry 230 nm were selected to be used in further tests. The use of preactivated cells or on the exponential growth phase showed better salicylic acid degradation percentages when compared to nonactivated cells or on the stationary growth state. Finally, the best cellular concentration used on the salicylic acid degradation was 0,1 g.L-1. Strain HK44 shows to be capable of degrade salicylic acid presented in simple aqueous systems, making this strain a promising tool for the application on a luminescent microbial sensor.

Com a intenção de criar um sensor microbiano, as condições ótimas para a biodegradação de ácido salicílico por Pseudomonas fluorescens HK44 foram determinadas neste estudo. Os experimentos cinéticos permitiram a definição dos tempos de 60 e 30 minutos como necessários para atingir a máxima degradação de ácido salicílico presente em meio com ou sem extrato de lêvedo, respectivamente. A degradação no meio sem extrato de lêvedo e a quantificação através de espectrofotometria 230 nm foram selecionadas para serem utilizadas em testes posteriores. O uso de células pré-ativadas ou na fase exponencial de crescimento apresentou melhores porcentagens de degradação de ácido salicílico quando comparadas a células não-ativadas ou no estado estacionário de crescimento. Além disso, a melhor concentração celular utilizada nessa degradação foi 0,1 g.L¹. A cepa HK44 parece ser capaz de degradar o ácido salicílico presente em sistemas aquosos simples, tornando este microrganismo uma ferramenta promissora para aplicação em um sensor microbiano luminescente.