Analysis of the spatio-temporal patterns of dry and wet conditions in the Huai River Basin using the standardized precipitation index

Located in a transition zone between the northern and southern climates in China, the Huai River Basin is prone to extreme events such as drought and flood. Based on the daily precipitation data at 134 stations between 1961 and 2013, this paper analyzed the spatial and temporal patterns of the dry and wet conditions in the Huai River Basin through the statistical analysis of the rainfall stations' annual and seasonal standard precipitation index (SPI) series. Annual SPI series exhibited a decreasing trend at 86 stations and an increasing trend at the remaining stations. None of the increasing trend was significant, while the decreasing trend was significant at two stations at 5% significance level (α = 0.05) and one station at 10% level. Seasonal-wise, there has been a prevailing trend of drying in spring and autumn, and wetting in summer and winter. The trends in the spring and summer SPI series have been mostly insignificant, while those in autumn and winter, significant (α = 0.10) at over 30 stations. The Pettitt test results indicated that the significant transitions (α = 0.10) in the autumn and winter SPI series mostly occurred in the middle to late 1980s. Comparison of the average number of dry and wet years between the two sub-periods of 1961–1984 and 1990–2013 suggested a significant increase (α = 0.05) in the average number of severely wet years across much of the basin. Overall, significant changes have already occurred in the dry and wet conditions of the Huai River Basin, which could have profound impacts on the food and water safety situation of the region

Red Light-Induced Systemic Resistance Against Root-Knot Nematode Is Mediated by a Coordinated Regulation of Salicylic Acid, Jasmonic Acid and Redox Signaling in Watermelon

Red light (RL) can stimulate plant defense against foliar diseases; however, its role in activation of systemic defense against root diseases remains unclear. Here, the effect of RL on root knot nematode Meloidogyne incognita (RKN) infestation was investigated in watermelon plants (Citrullus lanatus L.). Plants were exposed to 200 μmol m-2 s-1 photosynthetic photon flux density RL at the canopy level for 21 days using light-emitting photodiodes. The results showed that RL significantly suppressed gall formation and nematode development, which was closely associated with the RL-induced attenuation of oxidative stress in roots. Gene expression analysis showed that RL caused a transient upregulation of PR1 and WRKY70 transcripts at 7 days post inoculation in RKN-infected plants. Further investigation revealed that RL-induced systemic defense against RKN was attributed to increased jasmonic acid (JA) and salicylic acid (SA) content, and transcript levels of their biosynthetic genes in roots. Interestingly, while malondialdehyde content decreased, H2O2 accumulation increased in RL-treated RKN-plants, indicating a potential signaling role of H2O2 in mediating RL-induced systemic defense. Furthermore, analysis of enzymatic and non-enzymatic antidoxidants revealed that RL-induced enhanced defense agaist RKN was also attributed to increased activities of antioxidant enzymes as well as redox homeostasis. Taken together, these findings suggest that RL could enhance systemic resistance against RKN, which is mediated by a coordinated regulation of JA- and SA-dependent signaling, antioxidants, and redox homeostasis in watermelon plants

Development of Monoclonal Hybridoma Cell Lines and Extracting Antibody Against Fummonisin B1

Objective:To acquire monoclonal hybridoma cell lines against fummonisin B1(FB1) and extract monoclonal antibody against FB1.Methods: Coupling antigens of FB1-KLH and FB1-BSA with chemical methods and immune 6-8 weeks old femaleBALB/c mice with FB1-KLH. Integrating spleen cells with sp2/0 myeloma cells to acquire hybridoma cell lines secreting McAb against FB1. The method of multiple subclones was used to select cell lines stably secreting McAb. McAbs was got from ascites and purified. The subclass of antibody was measured and the molecular weight was identified. The specificity and sensitivity of McAb were identified with indirect competitive inhibition ELISA.Results:The results of serum from immuned mice showed that after five times of immunization the titer stables at 1×10-6, and the McAb belongs to IgG1 subclass, the light chain was ?, the molecular weight of heavy and light chain were 55kDa and 32kDa, respectively. ELISA results showed that McAb could react with FB1. The linear range indirect competitive inhibition ELISA is 10-500ng/ml.Conclusion:The monoclonal hybridoma cell lines and the high specificity,high sensitivity of FB1-McAb was got

Development of Monoclonal Hybridoma Cell Lines and Extracting Antibody Against Fummonisin B1

Objective:To acquire monoclonal hybridoma cell lines against fummonisin B1(FB1) and extract monoclonal antibody against FB1.Methods: Coupling antigens of FB1-KLH and FB1-BSA with chemical methods and immune 6-8 weeks old femaleBALB/c mice with FB1-KLH. Integrating spleen cells with sp2/0 myeloma cells to acquire hybridoma cell lines secreting McAb against FB1. The method of multiple subclones was used to select cell lines stably secreting McAb. McAbs was got from ascites and purified. The subclass of antibody was measured and the molecular weight was identified. The specificity and sensitivity of McAb were identified with indirect competitive inhibition ELISA.Results:The results of serum from immuned mice showed that after five times of immunization the titer stables at 1×10-6, and the McAb belongs to IgG1 subclass, the light chain was ?, the molecular weight of heavy and light chain were 55kDa and 32kDa, respectively. ELISA results showed that McAb could react with FB1. The linear range indirect competitive inhibition ELISA is 10-500ng/ml.Conclusion:The monoclonal hybridoma cell lines and the high specificity,high sensitivity of FB1-McAb was got