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Salt is one of the main stresses that limit plant growth, especially at the seedling stage, reducing crop production and severely impacting food security. However, the relationship between salt stress and sugar content regulated by sugar transporters remains unknown. Here, we investigated the salt tolerance of transgenic tomato seedlings ectopically expressing MdHT2.2, which is a fructose and glucose/H+ symporter located on the plasma membrane in apple. Although the contents of fructose, glucose and sucrose in the leaves of seedlings ectopically expressing MdHT2.2 obviously increased compared with those of WT seedlings, the transgenic seedlings were significantly less tolerance to salt stress. Under salt stress, the SlSOS1/2 and SlNHX1 genes were highly expressed, and the accumulation of Na+ was lower in the transgenic seedlings than in WT, however, ROS accumulated to a greater degree in the former, and the ROS-scavenging-related enzyme activities and AsA content were lower in the transgenic seedlings than WT. Taken together, these results indicated that the relatively low salt tolerance of the MdHT2.2 transgenic seedlings was related with the accumulation of ROS, which was caused by reduced ROS-scavenging ability. Our results offer proof that changes in sugar content caused by sugar transporters are related to salt tolerance, and provide new insight into the regulation of sugar content, quality improvement and stress tolerance.

Based on the fixed-point observation data in Qianhai Bay of Shenzhen in May 2020, the horizontal and vertical distribution characteristics of tidal current, wave in summer near Qianhai Bay of Shenzhen are analyzed. The results show that the correlation coefficient of high and low tide level between the Qianhai Bay and Chiwan hydrological station is 0.98. The former Bay is dominated by irregular semidiurnal tidal current, which basically rotates anticlockwise. Due to the special shape of Qianwan Bay, the average velocity in the bay is small, but the maximum velocity of flood tide is 0.48m/s, the maximum velocity of ebb tide is 0.45m/s, the possible maximum velocity is 0.64m/s at the bay mouth. The average wave height is 0.07m, the normal wave direction is southwest West (WSW), and the average period is 2.9s.

Phase shifting interferometry has become an important part of optical measurement field. In this paper, we described the phase shifting measurement principle, the analyzer interference model and the typical phase unwrapping methods. A novel phase unwrapping algorithm based on K-means clustering was proposed, and its calculation method and design process provided in order to complete three-dimensional morphology measurement. In the end, the algorithm was validated by experimental analysis of the standard sample that were consistent with the nominal and practical calibration values.

Developmental characteristics of dam-break research on earth-rock dam were reviewed and nowadays researchers emphasized corporation and paid more attention to quantitative description, multiple processes coupling and system integration in research. Combining with most concerned problems in dam safety management (DSM), achievements were reviewed in three fields: causal factors of disasters, dam-break process and flood propagation. In order to perfect a DSM system, researches on variations of dam material properties and corresponding effect in dam-break process, scale effect, similarity criteria of dam-break process and uncertainty analysis of common used models should be enhanced.