The unique importance of sweetpotato: Insights focusing on genetic improvements of salt and drought tolerance

•Sweetpotato provides generous unique advantages over other staple food crops.•Focusing on the limitation of salt and drought on the growth and yield of sweetpotato.•The genetic improvements of salt and drought tolerance are systematically summarized.•Classifying the molecular mechanisms of salt and drought tolerance of sweetpotato.•Exploring gaps and strategies for molecular breeding of highly resistant sweetpotato. Sweetpotato (Ipomoea batatas) is regarded as an all-around crop that provides generous unique advantages over other crops in addressing global problems of food, energy, health, and environmental security. However, salt and drought, as two major devastating stresses, can induce various morphological, physiological and biochemical damages in sweetpotato. Recent progresses in molecular genetics have delivered insights into the pleiotropic regulatory networks of plant responses to salt and drought stress at the organismic, cellular, and molecular levels, mainly involving osmotic adjustment, regulation of ionic homeostasis, transcriptional regulation and post-translation modification, and reactive oxygen species scavenging. In this review, the unique importance of sweetpotato and the growth interruption and yield loss caused by salt and drought stress were reviewed. The research progress concerning genetic improvement of sweetpotato tolerance in the above aspects in recent years was systematically summarized to better understand the genetic network, especially focusing on gene expression regulation and signaling pathways. Moreover, the gaps and strategies in molecular breeding of salt- and drought-tolerant sweetpotato were specifically discussed. The current review will facilitate a comprehensive understanding of the development directions of genetic improvement of sweetpotato tolerance. ‘Little’ sweetpotato makes a big difference, its potential appears limitless.