A increasing number of microRNAs have been shown to play important regulatory roles in plant responses to various metal stresses. However, little information about miRNAs especially miRNAs responsive to cadmium (Cd) stress is available in wheat. To investigate the role of miRNAs in responses to Cd stress, wheat seedlings were subjected to 250 μM Cd solution for 6, 12, 24 and 48 h, and analyses of morphological and physiological changes as well as the expression of five miRNAs and their corresponding targets were carried out. Our results demonstrated that miRNAs and their targets were differentially expressed in leaves and roots of wheat seedlings exposed to Cd stress. Furthermore, miR398 may involve in oxidative stress tolerance by regulating its target CSD to participate in Cd stress. Among ten miRNA-target pairs studied, nine pairs showed complex regulation relationship in leaves and roots of wheat seedlings exposed to Cd stress. These findings suggested that miRNAs are involved in the mediation of Cd stress signaling responses in wheat. The characterization of the miRNAs and the associated targets in responses to Cd exposure provides a framework for understanding the molecular mechanism of heavy metal tolerance in plants.

In the present paper, aerobic granules were developed in a sequencing batch reactor (SBR) using synthetic wastewater, and 81 % of granular rate was obtained after 15-day cultivation. Aerobic granules have a 96 % BOD removal to the wastewater, and the reactor harbors a mount of biomass including bacteria, fungi and protozoa. In view of the complexity of kinetic behaviors of sludge and biological mechanisms of the granular SBR, a cellular automata model was established to simulate the process of wastewater treatment. The results indicate that the model not only visualized the complex adsorption and degradation process of aerobic granules, but also well described the BOD removal of wastewater and microbial growth in the reactor. Thus, CA model is suitable for simulation of synthetic wastewater treatment. This is the first report about dynamical and visual simulation of treatment process of synthetic wastewater in a granular SBR.

The encryption algorithm has disadvantages like the long key making memory difficult and uneasy safekeeping, which causes a potential threat to the information security.