In a jujube orchard, cropping withgrass may influence bacterial diversity and ecological networks due to changes of physicochemical properties in soil, which has a serious effect on the stability of soil ecosystems. The aim of this study was to analyze the effects of different cultivation methods (CK: cleaning tillage; NG: cropping with native grass; VV: cropping with Vicia villosa) on the soil’s bacterial structure and its co-occurrence network in a jujube orchard. The results showed that the highest moisture content, total nitrogen, and organic matter in the rhizosphere soil of a jujube orchard was found in the VV group. The soil’s moisture content, total nitrogen, and organic matter in the VV group were 2.66%, 0.87 g kg⁻¹, and 5.55 mg kg⁻¹ higher than that found in the CK group. Compared to the CK group, the number of unique species in the rhizosphere soil in the NG and the VV groups increased by 7.33% and 21.44%. The PICRUSt and FAPROTAX analysis showed that sown grass had a greater influence on the ecological function of the soil’s bacteria. Cropping with Vicia villosa and native grass significantly increased aerobic chemoheterotrophy, nitrogen respiration, nitrate reduction related to biochemical cycles, and the relative abundance of genes related to carbohydrate metabolism and the biodegradation of xenobiotics. The bacterial network complexity in the NG group was higher than that in the CK and VV groups and was greatest in the hub nodes (OTU42, Bacteroidota; OTU541, Nitrospiraceae). In this study, the ecological benefit seen in the soil’s microbial function provides support to the theory that cropping with grass (Vicia villosa) increases the sustainable development of a jujube orchard.

The jujube witches’ broom (JWB) disease is a severe threat to jujube trees, with only a few cultivars being genuinely tolerant or resistant to phytoplasma. The defense mechanism of jujube trees against phytoplasma is still unclear. In this study, we aimed to investigate the tolerance mechanism of Indian jujube ‘Cuimi’ to JWB and identify the key genes that contribute to JWB high tolerance. Based on the symptoms and phytoplasma concentrations after infection, we confirmed the high tolerance of ‘Cuimi’ to JWB. Comparative transcriptome analysis was subsequently performed between ‘Cuimi’ and ‘Huping’, a susceptible cultivar of Chinese jujube. Unique gene ontology (GO) terms were identified in ‘Cuimi’, such as protein ubiquitination, cell wall biogenesis, cell surface receptor signaling pathway, oxylipin biosynthetic process, and transcription factor activity. These terms may relate to the normal development and growth of ‘Cuimi’ under phytoplasma infection. We identified 194 differential expressed genes related to JWB high tolerance, involved in various processes, such as reactive oxygen species (ROS), Ca²⁺ sensors, protein kinases, transcription factors (TFs), lignin, and hormones. Calmodulin-like (CML) genes were significantly down-regulated in infected ‘Cuimi’. We speculated that the CML gene may act as a negative regulatory factor related to JWB high tolerance. Additionally, the cinnamoyl-CoA reductase-like SNL6 gene was significantly up-regulated in infected ‘Cuimi’, which may cause lignin deposition, limit the growth of phytoplasma, and mediate immune response of ‘Cuimi’ to phytoplasma. Overall, this study provides insights into the contribution of key genes to the high tolerance of JWB in Indian jujube ‘Cuimi’.

WPR (WEB1/PMI2-related) genes play a crucial role in regulating chloroplast movement and leaf coloration in plants. Previous studies have shown that these genes are implicated in leaf yellowing, both in Arabidopsis thaliana and in Paulownia fortunei following infection with Paulownia witches’ broom. To investigate the functions of the ZjWPR genes in jujube, bioinformatics methods were employed to identify the ZjWPR gene family in jujube, analyze their protein physicochemical properties, gene structure, evolutionary relationships, and cis-acting elements in this study. The results revealed that the ZjWPR gene family in jujube comprised 10 members. Phylogenetic analysis showed that WPR genes were divided into two classes, with ZjWPR genes distributed across three subgroups within Class II. Conserved motif analysis indicated that motif 2, motif 3, motif 7, and motif 8 were the most highly conserved and most genes exhibited similar structures. Cis-element analysis in their promoter suggested that ZjWPR genes were regulated by multiple hormones and were associated with stress responses such as low temperature and drought. Moreover, all ZjWPR genes contained light-responsive elements. Expression analysis of the ZjWPR gene family under Jujube Witches’ Broom (JWB) stress showed that ZjWPR4 and ZjWPR5 were significantly up-regulated in JWB-susceptible jujube cultivars following phytoplasma infection, whereas no significant changes were detected in JWB-resistant cultivars. Additionally, the expression levels of ZjWPR2, ZjWPR3, and ZjWPR6 were also altered in response to infection, suggesting their potential involvement in the response to JWB stress and the associated leaf chlorosis process. Moreover, transient overexpression of ZjWPR4 and ZjWPR5 in sour jujube leaves led to significant reductions, in critical photosynthetic parameters, including Fv/Fm, Fq′/Fm′, and ETR compared with WT, thereby reinforcing their functional contribution to JWB-associated leaf yellowing. This study provides valuable insights for further functional characterization of the ZjWPR gene family in mediating JWB-induced leaf yellowing and related metabolic pathways.

Ascorbic acid (vitamin C) is a critical antioxidant influencing the nutritional quality of fruits. This study integrates metabolomic and transcriptomic analyses to investigate high-ascorbic-acid (HAA), medium-ascorbic-acid (MAA), and low-ascorbic-acid (LAA) jujube cultivars. Metabolomic profiling revealed significant enrichment of ascorbic acid and its precursors in HAA cultivars, whereas MAA and LAA cultivars showed lower levels. Transcriptomic analysis identified 107 differentially expressed genes (DEGs) across the three groups. Compared with LAA, 139 differentially accumulated metabolites (DAMs) were identified in HAA, with more down-accumulated (77) than up-accumulated (62); compared with MAA, 235 DAMs were found in HAA, with significantly more up-accumulated (180) than down-accumulated (55); 250 DAMs with different accumulation patterns between LAA and MAA included 199 up-accumulated and 51 down-accumulated; and 16 DAMs were common in all three comparison combinations. Potential key regulatory genes such as GDP-mannose-3′,5′-epimerase (GME) and L-galactose-1-phosphate phosphatase (GPP) were highlighted. Weighted Gene Co-expression Network Analysis (WGCNA) detected possible core genes participating in ascorbic acid biosynthesis pathways. This study provides novel insights into the genetic and metabolic basis of ascorbic acid accumulation, potentially providing valuable targets for molecular breeding.