RESUMEN
Soil salinity is one of the major plant growth and yield-limiting constraints in arid and semi-arid regions of the world. In addition to the oxidative damage, increasing salt stress is associated with elevated cellular ethylene levels due to the synthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) in large amounts. The objective of the current study was to elucidate the inoculation effect of an ACC deaminase (ACCD)-producing phytobeneficial strain Achromobacter sp. FB-14 on rice plants to alleviate the salinity effects by upregulation of the stress-responsive CIPK genes. The strain FB-14 was isolated by using nutrient agar medium at 855 mM NaCl concentration and it was taxonomically identified as Achromobacter sp. with more than 99% 16S rRNA gene sequence similarity with many Achromobacter species. The strain FB-14 demonstrated substantial in vitro potential for ACCD activity, synthesis of indole compounds, and phosphate solubilization up to 100 mM NaCl concentration in the culture medium. The gene corresponding to ACCD activity (acdS) was amplified and sequenced in order to confirm the inherent enzyme activity of the strain at a molecular level. The rifampicin-resistant derivative of strain FB-14 was recovered from the rice rhizosphere on antibiotic medium up to 21 days of sowing. Moreover, the strain FB-14 was inoculated on rice plants under salinity and it not only enhanced the growth of rice plants in terms of root and shoot length, and fresh and dry weight, but also upregulated the expression of stress-responsive CIPK genes (OsCIPK03, OsCIPK12, and OsCIPK15) according to the results of qRT-PCR analysis. To the best of our knowledge, this is the first report deciphering the role of plant-beneficial Achromobacter strain relieving the rice plants from salt stress by promoting the growth and enhancing the expression of stress-responsive CIPK genes.
Asunto(s)
Achromobacter/enzimología , Liasas de Carbono-Carbono/metabolismo , Oryza/crecimiento & desarrollo , Oryza/microbiología , Proteínas Serina-Treonina Quinasas/genética , Estrés Salino/genética , Achromobacter/genética , Regulación de la Expresión Génica de las Plantas , Oryza/genética , ARN Ribosómico 16S/genética , Suelo/química , Microbiología del Suelo , Regulación hacia ArribaRESUMEN
The normal distribution has a central place in distribution theory and statistics. We propose the log-odd normal generalized (LONG) family of distributions based on log-odds and obtain some of its mathematical properties including a useful linear representation for the new family. We investigate, as a special model, the log-odd normal power-Cauchy (LONPC) distribution. Some structural properties of LONPC distribution are obtained including quantile function, ordinary and incomplete moments, generating function and some asymptotics. We estimate the model parameters using the maximum likelihood method. The usefulness of the proposed family is proved empirically by means of a real air pollution data set.
RESUMEN
Abstract In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Estabilidad de Medicamentos , Cromatografía de Fase Inversa/métodos , Antibacterianos/análisis , Dexametasona/análisis , Estudio de ValidaciónRESUMEN
BACKGROUND: Current study has been designed to evaluate the chemical composition of essential and fixed oils from stem and leaves of Perovskia abrotanoides and antioxidant and antimicrobial activities of these oils. RESULTS: GC-MS analysis of essential oil identified 19 compounds with (E)-9-dodecenal being the major component in stem and hexadecanoic acid in leaves. In contrast, GC-MS analysis of fixed oil showed 40 constituents with α-amyrin the major component in stem and α-copaene in leaves. The antioxidant activity showed the highest value of 76.7% in essential oil from leaves in comparison with fixed oil from stem (45.9%) through inhibition of peroxidation in linoleic acid system. The antimicrobial assay tested on different microorganisms (e.g. E. coli, S. aureus, B. cereus, Nitrospira, S. epidermis, A. niger, A. flavus and C. albicans) showed the higher inhibition zone at essential oil from leaves (15.2 mm on B. cereus) as compared to fixed oil from stem (8.34 mm on S. aureus) and leaves (11.2 mm on S. aureus). CONCLUSIONS: The present study revealed the fact that essential oil analyzed from Perovskia abrotanoides stem and leaves could be a promising source of natural products with potential antioxidant and antimicrobial activities, as compared to fixed oil.
Asunto(s)
Antiinfecciosos/química , Antioxidantes/química , Lamiaceae/química , Hojas de la Planta/química , Aceites de Plantas/farmacología , Tallos de la Planta/química , Alcanos/análisis , Alcanos/farmacología , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Aspergillus/efectos de los fármacos , Bacillus cereus/efectos de los fármacos , Candida albicans/efectos de los fármacos , Pruebas Antimicrobianas de Difusión por Disco , Escherichia coli/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Peroxidación de Lípido/efectos de los fármacos , Éteres Metílicos/análisis , Éteres Metílicos/farmacología , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/análisis , Ácido Oleanólico/farmacología , Ácido Palmítico/análisis , Ácido Palmítico/farmacología , Triterpenos Pentacíclicos/análisis , Triterpenos Pentacíclicos/farmacología , Aceites de Plantas/química , Sustancias Reductoras/análisis , Sesquiterpenos/análisis , Sesquiterpenos/farmacología , Staphylococcus/efectos de los fármacos , Ácidos Esteáricos/análisis , Ácidos Esteáricos/farmacologíaRESUMEN
BACKGROUND: Current study has been designed to evaluate the chemical composition of essential and fixed oils from stem and leaves of Perovskia abrotanoides and antioxidant and antimicrobial activities of these oils. RESULTS: GC-MS analysis of essential oil identified 19 compounds with (E)-9-dodecenal being the major component in stem and hexadecanoic acid in leaves. In contrast, GC-MS analysis of fixed oil showed 40 constituents with α-amyrin the major component in stem and α-copaene in leaves. The antioxidant activity showed the highest value of 76.7% in essential oil from leaves in comparison with fixed oil from stem (45.9%) through inhibition of peroxidation in linoleic acid system. The antimicrobial assay tested on different microorganisms (e.g. E. coli, S. aureus, B. cereus, Nitrospira, S. epidermis, A. niger, A. flavus and C. albicans) showed the higher inhibition zone at essential oil from leaves (15.2 mm on B. cereus) as compared to fixed oil from stem (8.34 mm onS. aureus) and leaves (11.2 mm on S. aureus). CONCLUSIONS: The present study revealed the fact that essential oil analyzed from Perovskia abrotanoides stem and leaves could be a promising source of natural products with potential antioxidant and antimicrobial activities, as compared to fixed oil.