Mechanisms of increasing salt resistance of vegetables by grafting

Abstract

Soil salinity is a serious threat to horticultural production. Improving salt tolerance of vegetables by breeding is a difficult task as salt tolerance is a quantitative trait, regulated by a large number of genes. As a traditional agronomic method, grafting, which is widely practiced in vegetables, especially among members of Cucurbitaceae and Solanaceae, is a useful tool for reducing yield loss caused by salinity. However, the underlying mechanisms of this phenomenon remain largely unknown. Numerous studies have been conducted to uncover these mechanisms by which grafting improves salt tolerance in vegetables. This review summarizes the studies that have been conducted on this topic. In this review, the effects of salt stress on vegetable crops were discussed, and the four main mechanisms by which grafting increases the salt resistance of vegetables, namely, restricting the transport of toxic ions, enhancing the antioxidant system, enhancing the stability of the photosynthetic system, and sending root signals, were discussed. This review concludes by identifying several prospects for future research on increasing the adoption of grafting in vegetables under salinity stress.