FIGURE 1 The growth changes of S. miltiorrhiza seedlings under abiotic stress. (a), (b), and (c) respectively represent the changes in the growth effects of the superposition of various environmental factors under the stress of nitrogen, phosphorus and nitrogen and phosphorus deficiency, and (d) represents the changes in the growth effects of the superposition of drought and high temperature. * indicating a significant difference to the CK treatment, p< 0.05.