Drought stress is a major abiotic stress of common bean (Phaseolus vulgaris L.) throughout the world. Increasing the proline accumulation contributes to enhance crop drought tolerance. A cDNA for δ-ornithine aminotransferase (δ-OAT), an enzyme involved in the biosynthesis of proline, was isolated from Phaseolus vulgaris (PvOAT). PvOAT exhibits 87.4 and 39.8% similarity of the deduced amino acid sequences with δ-OAT from Glycine max and Vigna aconitifolia, respectively. The transcriptional analysis revealed that PvOAT was strongly induced by drought stress. And the expression of PvOAT was higher in leaves than that in the root and stem of common bean by drought stress. Similar increase of the proline accumulation was observed in leaves and roots of common bean by drought stress. Furthermore, the proline content, the PvOAT expression and the PvOAT enzyme activity in cultivar F5575 was significantly (P<0.01) higher than that in cultivar F4851 under drought-stress conditions. Interestingly, it had been observed that, in the later stage of drought stress, the proline steadily maintained at the maximum level maybe result from the PvOAT enzyme activity increasing steadily. These results indicated that the expression of PvOAT and the accumulation of proline induced by drought stress treatment were related to the degree of common bean drought tolerance. So our results support the view that δ-OAT is associated with proline synthesis under drought stress conditions.

Soybean cyst nematode (SCN) is one of the most devastating pathogen for soybean. Therefore, identification of resistant germplasm resources and resistant genes is needed to improve SCN resistance for soybean. Soybean varieties Huipizhiheidou and Wuzhaiheidou were distributed in China and exhibited broad spectrums of resistance to various SCN races. In this study, these two resistant varieties, combined with standard susceptible varieties (Lee and Essex), were utilized to identify the differentially expressed transcripts after infection with SCN race 4 between resistant and susceptible reactions by using the Affymetrix Soybean Genome GeneChip. Comparative analyses indicated that 21 common genes changed significantly in the resistant group, of which 16 increased and 5 decreased. However, 12 common genes changed significantly in the susceptible group, of which 9 increased and 3 decreased. Additionally, 27 genes were found in common between resistant and susceptible reactions. The 21 significantly changed genes in resistant reaction were associated with disease and defense, cell structure, transcription, metabolism, and signal transduction. The fold induction of 4 from the 21 genes was confirmed by quantitative RT-PCR (qRTPCR) analysis. Moreover, the gene ontology (GO) enrichment analyses demonstrated the serine family amino acid metabolic process and arginine metabolic process may play important roles in SCN resistance. This study provided a new insight on the genetic basis of soybean resistance to SCN race 4, and the identified resistant or resistant-related genes are potentially useful for SCN-resistance breeding in soybean.

Hydrogen peroxide (H2O2) is an important signaling molecule in ethylene-induced stomatal closure in Arabidopsis thaliana. Early studies on the sources of H2O2 mainly focused on NADPH oxidases and cell-wall peroxidases. Here, we report the involvement of polyamine oxidases (PAOs) in ethylene-induced H2O2 production in guard cells. In Arabidopsis epidermal peels, application of PAO inhibitors caused the failure of ethylene to induce H2O2 production and stomatal closure. Results of quantitative RT-PCR analysis and pharmacological experiments showed that AtPAO2 and AtPAO4 transcripts and activities of PAOs were both induced by ethylene. In transgenic Arabidopsis plants over-expressing AtPAO2 and AtPAO4, stomatal movement was more sensitive to ethylene treatment and H2O2 production was also significantly induced. The increased H2O2 production in the transgenic lines compared to the wild-type plants suggests that AtPAO2 and AtPAO4 probably are involved in ethylene-induced H2O2 production. Several factors which induce stomatal closure such as dehydration and high salinity all enhanced the expression of AtPAO2 and AtPAO4 to different degrees. Moreover, GFPAtPAOs fusion protein localized in the nucleus, cytoplasm, and cell wall of the guard cells. Therefore, our results strongly indicated that PAO is a source of H2O2 generation in Arabidopsis guard cells and plays crucial roles in stomatal movement.

Various fishery information systems have been developed in different times and on different platforms. Web service application composition is crucial in the sharing and integration of fishery data and information. In the present paper, a heuristic web service composition method based on fishery ontology is presented, and the proposed web services are described. Ontology reasoning capability was applied to generate a service composition graph. The heuristic function was introduced to reduce the searching space. The experimental results show that the algorithm used considers the services semantic similarity and adjusts web service composition plan by dynamically relying on the empirical data.