Fig. 7 Changes of activities of acid invertase (INV) and sucrose synthase (SS) in grains of the semi-winter wheat cultivars Yangmai 158 (A) and Yangmai 931 (B) after soil drying was applied. NN and HN indicate normal and high levels of nitrogen application at heading time, respectively. WW, MD, and SD are well-watered, mildly dried, and severely dried treatments at grain filling, respectively (see details in the Materials and Methods section). Arrows in the figures indicate the start of soil drying treatments. Vertical bars represent ±SE of the mean where these exceed the size of the symbol