Characterizing Fluorescence Emissions of Hairpin DNA-Templated Silver Nanoclusters by cDNA Hybridization

Stem-loop hairpin DNA probes have high hybridization specificity and unique selectivity to target molecules such as DNA and small molecules. DNA-templated silver nanoclusters (DNA-AgNCs) has been widely used to detect biomolecules of interest due to the photostable, bright, and efficient methods. In this study, we measured fluorescence emission of hairpin DNA upon hybridization with cDNA and mutant cDNA (cDNA-1) or mutant cDNA containing mismatched bases in the stem region (cDNA-2). Fluorescence intensity of hairpin DNA-AgNCs in the presence of cDNA was 1.80 times higher than that of hairpin DNA-AgNCs alone, but decreased to 66% in the presence of cDNA-1 containing mismatched base corresponding to the hairpin stem region. This study demonstrated that fluorescence intensities of hairpin DNA-AgNCs were dependent on hybridization with either wild-type and mutant cDNAs.

Genes Expressed in Ascochyta raftiei-Inoculated Chickpea Plants and Elicited Cell Cultures as Detected by Differential cDNA-Hybridization

In response to the exogenous application of elicitors and attempted invasion by pathogens, plants exhibit a wide range of defense reactions. To understand the defense mechanism s at the level of gene activation and deactivation, differential screenings were perform ed to isolate cDNA clones which are differentially expressed in pathogen-inoculated resistant chickpea plants and elicitor-treated cell cultures. A plenty of genes were isolated and arranged in 5 groups, namely defense-related pathways, signal transduction pathways, regulation of gene expression, catabolic pathways and primary metabolism . Most of these genes were activated although several genes were also found to be suppressed. We discuss the plausible functions of cDNA products in plant defense responses. The cDNA s provide a variety of tools to investigate m olecular mechanisms of defense responses and clearly reflect the massive genomic and metabolic changes which occur during manifestation of antimicrobial defense.