**5. Conclusions**

In the present study, we found that 10 mg L−<sup>1</sup> V treatment improved the growth and biomass of the sweet potato plant. However, V at higher levels (25, 50, and 75 mg L−1) significantly reduced the growth of sweet potato by altering its physiological and biochemical mechanisms. The higher level of V treatments (25, 50, and 75 mg L<sup>−</sup>1) significantly reduced the RWC, chlorophyll content, gas exchange elements of leaf, and stomatal traits, which eventually affected the growth of sweet potato. The decline in root morphological traits was observed at the higher V treatment, and we also detected maximum V concentration and uptake in the roots than in the shoots of sweet potato. It was also observed that the V application increased ROS production. Overall, this study will help to understand the physiological tolerance mechanism of V in sweet potato plants. In this study, we focused on the effect of V stress on the morphological and physiological aspects of sweet potato. Besides, this study was conducted in a hydroponically controlled environment, and thus, open-field experiments are encouraged to unravel the more precise effects of V on sweet potato, as in open-field conditions the plants are exposed to several other biotic and abiotic stresses. Moreover, further studies are also required to investigate the molecular mechanism underlying cell death induced by V toxicity in the sweet potato plant. Furthermore, we suggest using various chemicals, phytohormones, and nanoparticles to prevent V toxicity and stimulate sweet potato growth and production.

**Author Contributions:** All authors contributed to the manuscript. Conceptualization: G.Z. and S.K. Funding acquisition: G.Z. Data curation, investigation, validation, and writing—original draft: S.K. Methodology: S.K., Y.L. and M.W. Writing—review and editing: S.K., S.F., A.Q. and Z.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** The earmarked fund for CARS-10-Sweetpotato supported this work.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this article will be made available without any reservation.

**Acknowledgments:** The authors acknowledge all the staff members of the Laboratory of Analytical and Testing Center, Hainan University, for providing technical support and help during the experimental work.

**Conflicts of Interest:** The authors declare that they have no conflict of interest.
