Toxicity effects of zinc supply on growth revealed by physiological and transcriptomic evidences in sweet potato (Ipomoea batatas(L.) Lam)

Abstract

Abstract Zinc toxicity affects crop productivity and threatens food security and human health worldwide. Unfortunately, accumulation patterns of zinc and the harm of excessive zinc on sweet potato have not been well explored. In present research, two genotypes sweet potato varieties with different accumulation patterns of zinc were selected for analyzing the effects of excessive zinc on sweet potato via hydroponic and field cultivation experiments. The results indicated that transfer coefficient was closely related to zinc concentration in storage root of sweet potato. Excessive zinc inhibited the growth of sweet potato plants by causing imbalanced mineral concentration, destroying the cellular structure and reducing photosynthesis. Further, a total of 17,945 differentially expressed genes were identified in in the two genotypes under zinc stress by transcriptomic analysis. And differentially expressed genes involved in absorption and transport of zinc, defense network and transcription factors played important roles in responding to zinc stress. In conclusion, this study provides a reference for the selection of sweet potato varieties in zinc contaminated soil and lays a foundation of investigating the tolerance of sweet potato for excessive zinc, which is meaningful for environmental safety and human health.