Cloning and characterization of defense-related genes from Populus szechuanica infected with rust fungus Melampsora larici-populina.

Characterization of defense-related genes is critical for breeding disease-resistant poplar varieties and for better management and control of leaf rust disease. In the present study, full-length cDNAs of five Populus szechuanica defense-related (PsDR) genes, pathogen-related protein 1 (PsPR1), ß-1,3-glucanase (PsGns), thaumatin-like protein 1 (PsTLP1), thaumatin-like protein 2 (PsTLP2), and phenylalanine ammonia-lyase (PsPAL), were cloned from the leaves of P. szechuanica infected with Melampsora larici-populina (MLP). PsPR1 (728 bp), PsGns (1189 bp), PsTLP1 (929 bp), PsTLP2 (885 bp), and PsPAL (2586 bp) were predicted to encode 161, 347, 245, 225, and 711 amino acid residue-containing proteins with isoelectric points of 8.53, 4.96, 4.51, 7.32, and 5.87, respectively. Moreover, the deduced PsDR proteins displayed more than 90% similarity to proteins from other Populus species. In response to the avirulent isolate, Sb052, and the virulent isolate, Th053, of MLP, the expression of PsDR genes was rapidly up-regulated in the leaves of P. szechuanica, peaked at 2 or 7 days post-inoculation (dpi), with levels in the incompatible interaction being higher than those in the compatible interaction. Meanwhile, the expression of PsDR genes (except for PsGns) was also differentially up-regulated at 3, 7, or 18 dpi in the petioles of the infected leaves, leaves next to the inoculated leaves, and in the top buds of the infected plants, respectively, compared to that at 0 dpi. These results suggest that these PsDR genes could play distinctive roles in the defense response of poplar against rust infection.

Molecular cloning and expression profile of an ATP-binding cassette (ABC) transporter gene from the hemipteran insect Nilaparvata lugens.

The ATP-binding cassette (ABC) transporters belong to a large superfamily of proteins that have important physiological functions in all living organisms. In insects, ABC transporters have important functions in the transport of molecules, and are also involved in insecticide resistance, metabolism, and development. In this study, the Nilaparvata lugens Stal (Hemiptera: Delphacidae) ABCG (NlABCG) gene was identified and characterized. The complete mRNA sequence of NlABCG was 2608-bp long, with an open reading frame of 2064 bp encoding a protein comprised of 687 amino acids. The conserved regions include three N-glycosylation and 34 phosphorylation sites, as well as seven transmembrane domains. The amino acid identity with the closely related species Acyrthosiphon pisum was 42.8%. Developmental expression analysis using quantitative real-time reverse transcriptase PCR suggested that the NlABCG transcript was expressed at all developmental stages of N. lugens. The lowest expression of NlABCG was in the 1st instar, and levels increased with larval growth. The transcript profiles of NlABCG were analyzed in various tissues from a 5th instar nymph, and the highest expression was observed in the midgut. These results suggest that the sequence, characteristics, and expression of NlABCG are highly conserved, and basic information is provided for its functional analysis.

Formation of and countermeasures for subacute coronary stent thrombosis in elderly diabetic patients.

The aim of this study was to evaluate and investigate the pathogenetic mechanism and countermeasures of subacute thrombosis (SAT) after coronary stenting in elderly diabetic patients. The clinical characteristics and pathogenetic mechanisms in 3 cases of SAT after stent implantations in elderly diabetic patients were retrospectively examined to determine the treatment strategies for SAT. Among 98 patients with diabetes who had coronary stents implanted or were >60 years of age, three (3.06%) had SAT. One case of SAT was diagnosed by angiography; coronary balloon dilatation, thrombolysis, and re-perfusion resulted in full recovery in this case. The second case involved potential SAT, and in the third case, SAT was not ruled out. Two cases were characteristic of ST-segment elevation myocardial infarction, and one case, in which SAT was not ruled out, resulted in sudden death. SAT within a stent may be related to intraoperative stent malapposition caused by a grade C lesion, age, diabetes, chronic total occlusion, or postoperative irregular administration of medication.

Identification and characterization of differentially expressed genes during incompatible interaction between the foliar rust Melampsora larici-populina and poplar.

Poplars are extensively cultivated worldwide, and their susceptibility to the foliar rust fungus leads to considerable damages in plantations. To better understand the molecular basis of poplar responses to the foliar rust, suppression subtractive hybridization was used to identify the potential important or novel genes involved in the Populus szechuanica infection by Melampsora larici-populina. A total of 515 expressed sequence tags (ESTs) with high quality were obtained and clustered into 66 contigs and 75 singletons to give a set of 141 uniESTs. The nucleotide Basic Local Alignment Search Tool (BLASTn) program was used to search for homologous sequences of the uniESTs in the GenBank database. Among them, 92.9% showed homology to the poplar genome, and 2% showed similarity to the rust fungus genome. In addition, homology to known genes was analyzed by the BLASTx algorithm, and approximately 50% of the uniESTs were significantly homologous to genes encoding proteins with known functions. Based on a reverse transcription-polymerase chain reaction (PCR) and quantitative PCR approach, five uniESTs were analyzed, and the results showed that the expression level of the thaumatin-like gene was highest at 72 h post-inoculation, and the pathogenesis-related protein 1 gene was highest at 48 h post-inoculation. The information generated in this study provides new clues to aid in the understanding of incompatibility between poplar and the foliar rust.