Novel Multiresistant Osmotin-like Protein from Sweetpotato as a Promising Biofungicide to Control Ceratocystis fimbriata by Destroying Spores through Accumulation of Reactive Oxygen Species.

Osmotin-like proteins (OLPs) play an important role in host-plant defense. In this study, a novel multiresistant OLP (IbOLP1) was screened from sweetpotato (Ipomoea batatas) with a molecular weight of 26.3 kDa. The expression level of IbOLP1 was significantly higher in resistant cultivars than susceptible ones after inoculation with Ceratocystis fimbriata, which causes black rot disease in sweetpotato. The expression of IbOLP1 in Pichia pastoris led to the lysis of yeast cells themselves. The recombinant IbOLP1 displayed antifungal, antibacterial, and antinematode activity and stability. IbOLP1 could restrain the mycelial growth and lyse spores of C. fimbriata, distinctly reducing the incidence of black rot in sweetpotato. The IbOLP1 can trigger the apoptosis of black rot spores by elevating the intracellular levels of reactive oxygen species. Collectively, these findings suggest that IbOLP1 can be used to develop natural antimicrobial resources instead of chemical agents and generate new, disease-resistant germplasm.

[Characteristics of Stable Isotope in Precipitation and Its Relationship with ENSO in Shanghai].

A total of 70 precipitation samples were collected from August 2014 to August 2015 in Shanghai and the oxygen and hydrogen isotope of precipitation were analyzed. The relationship between the δ18O and deuterium excess of precipitation and ENSO events was addressed. The results showed that δD and δ18O of precipitation in Shanghai were higher in winter and spring than in summer and fall. The slope of meteoric water line with these data was a little smaller than the global meteoric water line. The main reason could be the unbalanced secondary evaporation in the process of precipitation. The correlation between the δ18O in precipitation and temperature and precipitation varied in different time scales. On a seasonal scale, this work revealed that there was no significant temperature effect in winter, but significant precipitation effect was found in the annual scales, which was obviously affected by the atmospheric circulation. δ18O values and deuterium excess in precipitation recorded the La Niña and El Niño conversion process. During the La Niña event, the δ18O and d values were more negative than those in the El Niño event.