Fleshy fruit ripening is a unique biological process that involves dramatic changes in a diverse array of cellular metabolisms. The regulation of these metabolisms is essentially mediated by cellular signal transduction of internal (e.g., hormones) and external cues (i.e., environmental stimuli). Mitogen-activated protein kinase (MAPK) signaling pathways play crucial roles in a diverse array of biological processes, such as plant growth, development and biotic/abiotic responses. Accumulating evidence suggests that MAPK signaling pathways are also implicated in fruit ripening and quality formation. However, while MAPK signaling has been extensively reviewed in Arabidopsis and some crop plants, the comprehensive picture of how MAPK signaling regulates fruit ripening and quality formation remains unclear. In this review, we summarize and discuss research in this area. We first summarize recent studies on the expression patterns of related kinase members in relation to fruit development and ripening and then summarize and discuss the crucial evidence of the involvement of MAPK signaling in fruit ripening and quality formation. Finally, we propose several perspectives, highlighting the research matters and questions that should be afforded particular attention in future studies.

The texture of fresh jujube fruit is related to its popularity and commercial value. The metabolic networks and essential genes that regulate the texture of jujube (Ziziphus jujuba) fruit are still unknown. In this study, two jujube cultivars with significantly different textures were selected by a texture analyzer. The four developmental stages of the exocarp and mesocarp of jujube fruit were studied separately using metabolomic and transcriptomic analyses. Differentially accumulated metabolites were enriched in several critical pathways related to cell wall substance synthesis and metabolism. Transcriptome analysis confirmed this by finding enriched differential expression genes in these pathways. Combined analysis showed that ‘Galactose metabolism’ was the most overlapping pathway in two omics. Genes such as β-Gal, MYB and DOF may affect fruit texture by regulating cell wall substances. Overall, this study provides an essential reference for the establishment of texture-related metabolic and gene networks of jujube fruit.

Aiming at the problems of tree vigor decline and unstable fruit quality caused by soil impoverishment and easy nutrient loss in the Ziziphus jujuba Mill. ‘Huizao’ (Huizao) producing areas of southern Xinjiang, the application effect of bag-controlled slow-release fertilizer (BCSRF) in this region remains unclear. In this study, a field experiment was conducted with four fertilization concentration gradients, including CK (0 kg/ha), T1 (22 kg/ha), T2 (44 kg/ha), and T3 (66 kg/ha), to investigate the effects of BCSRF on soil nutrient dynamics and plant growth, as well as the fruit yield and quality of Huizao. The results showed that BCSRF could effectively maintain the supply levels of soil alkali-hydrolysable nitrogen, available phosphorus, and available potassium during key growth periods, among which the T3 treatment exhibited the most significant effect. This treatment not only significantly increased the yield per plant of Huizao by 39.34% compared with the control, but also markedly enhanced the contents of the endogenous substance, including soluble sugar and cyclic adenosine monophosphate. This study confirms that under the condition of sandy loam soil in southern Xinjiang, a single basal application of an appropriate amount of BCSRF can achieve continuous nutrient supply, simultaneously improve soil fertility and fruit quality, providing a theoretical basis and technical guidance for simplified and efficient fertilization in local jujube orchards.