Jujube (Ziziphus jujuba Mill.) is one of the three traditional woody crop species in China, where it originated from the middle and lower reaches of the Yellow River. Jujube is considered one of the oldest cultivated fruit trees species in the world, as its utilization can be traced back to more than 7000 years ago. The jujube has important nutritional, economic, and ecological values, hence it is well received by both planters and consumers. At present, jujube cultivation has spread to more than 48 countries and provides a pathway for Chinese farmers to produce a lucrative cash crop. Jujube is regarded as a superfruit of the future due to its excellent nutritional profile. Social progress and economic shifts leading to the improvement of living standards influence the value of jujube to consumers, who have gradually shifted toward functional foods, while at the same time, consumer desires and environmental pressures change the breeding goals for new jujube varieties. In this review, we summarize the origin, classification, and historical, as well as modern, uses of jujube. We also provide some advice on the establishment of breeding objectives in this new period of jujube development. This review aims to provide useful references for researchers new to jujube, to guide shareholders in the jujube industry, and to formulate breeding objectives for the modern development of elite jujube cultivars.

Controlling the tree size of fruit species such as peach can reduce the amount of labor and input needed for orchard management. The phytohormone gibberellin (GA) positively regulates tree size by inducing degradation of the GA signaling repressor DELLA. The N-terminal DELLA domain in this protein is critical for its GA-dependent interaction with the GA receptor GID1 and the resulting degradation of the DELLA protein, which allows for growth-promoting GA signaling. In this study, a DELLA family member, PpeDGYLA, contains a DELLA domain but has amino acid changes in three conserved motifs (DELLA into DGYLA, LEQLE into LERLE, and TVHYNP into AVLYNP). In the absence or presence of GA₃, the PpeDGYLA protein did not interact with PpeGID1c and was stable in 35S-PpeDGYLA peach transgenic callus. The overexpression of PpeDGYLA in both polar and Arabidopsis showed an extremely dwarfed phenotype, and these transgenic plants were insensitive to GA₃ treatment. PpeDGYLA could interact with PpeARF6-1 and -2, supposed growth-promoting factors. It is suggested that the changes in the DELLA domain of PpeDGYLA may, to some extent, account for the severe dwarf phenotype of poplar and Arabidopsis transgenic plants. In addition, our study showed that the DELLA family contained three clades (DELLA-like, DELLA, and DGLLA). PpeDGYLA clustered into the DGLLA clade and was expressed in all of the analyzed tissues. These results lay the foundation for the further study of the repression of tree size by PpeDGYLA.