RESUMEN
To research whether poly-L-lysine-starch nanoparticle (PLL-StNP) could protect DNA from ultrasound damage or not, a series experiments were carried out: plasmid DNA-PLL-StNP complexes were treated with ultrasound for diverse times; the electrophoresis result proved that DNA bound to the complexes all the same. To investigate whether the conjugated DNA was completely protected or not, cDNA fragments bound to PLL-StNP were treated with ultrasound, and matched molecular beacons (MBs) were added. The cDNA-MB-PLL-StNP complexes exhibited dramatically increasing fluorescence, and had the same intensity as that of those MBs that were hybridized with free cDNA fragments. After being treated by ultrasound, the pIRGFP plasmid DNA-PLL-StNP complexes were transferred into COS-7 cells mediated by ultrasound. Green fluorescence protein expressed in most of the cells. Those results indicated that PLL-StNP could completely protect DNA from ultrasound damage. Furthermore, the DNA kept the same function as untreated one.
Asunto(s)
ADN/química , Nanoestructuras/química , Polilisina/química , Almidón/química , Ultrasonido , Materiales BiocompatiblesRESUMEN
Gibberellin 2-oxidase (GA 2-oxidase) plays very important roles in plant growth and development. In this study, the AtGA2ox8 gene, derived from Arabidopsis (Arabidopsis thaliana), was transformed and over-expressed in rapeseed (Brassica napus L.) to assess the role of AtGA2ox8 in biomass accumulation and lignification in plants. The transgenic plants, identified by resistant selection, polymerase chain reaction (PCR) and reverse-transcription PCR (RT-PCR) analyses, and green fluorescence examination, showed growth retardation, flowering delay, and dwarf stature. The fresh weight and dry weight in transgenic lines were about 21% and 29% lower than those in wild type (WT), respectively, and the fresh to dry weight ratios were higher than that of WT. Quantitative measurements demonstrated that the lignin content in transgenic lines decreased by 10%-20%, and histochemical staining results also showed reduced lignification in transgenic lines. Quantitative real-time PCR analysis indicated that the transcript levels of lignin biosynthetic genes in transgenic lines were markedly decreased and were consistent with the reduced lignification. These results suggest that the reduced biomass accumulation and lignification in the AtGA2ox8 over-expression rapeseed might be due to altered lignin biosynthetic gene expression.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/enzimología , Arabidopsis/genética , Brassica napus/crecimiento & desarrollo , Brassica napus/genética , Genes de Plantas , Oxigenasas de Función Mixta/genética , Proteínas de Arabidopsis/metabolismo , Secuencia de Bases , Biomasa , Brassica napus/metabolismo , Cartilla de ADN/genética , ADN de Plantas/genética , Expresión Génica , Lignina/metabolismo , Oxigenasas de Función Mixta/metabolismo , Plantas Modificadas Genéticamente , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transformación GenéticaRESUMEN
An amperometric biosensor has been developed for the determination of H(2)O(2) in plant samples. Horseradish peroxidase (HRP) is immobilized on a sandwiched nano-Au particle / m-phenylenediamine polymer film by glutaraldehyde cross-linking. The film is formulated on the carbon paste electrode (CPE) blended with ferrocene as an electron transfer mediator. On the low concentration range, the current response is related to the H(2)O(2) concentration linearly from 0 to 8x10(-6) M with a detection limit of 1.3x10(-7) M. On a wider concentration range of 8x10(-6) to 1.4x10(-4) M, the reciprocal of current response is linearly related to the reciprocal of H(2)O(2) concentration. The apparent Michaelis-Menten constant (K(m)(app)) was calculated to be 0.0334 mM. The sensor has been tested by determining H(2)O(2) concentration in plant leaf samples.