Nutrient stress harms plant growth and yield. Melatonin is a biologically active, multifunctional hormone that relieves abiotic stress in plants. Although previous studies have shown that melatonin plays an important role in improving nutrient-use efficiency, the mechanism of its regulation of nutrient stress remains unclear. In this study, melatonin was applied to apple plants under nutrient stress, and morphological indices, physiological and biochemical indices, and stomatal morphology were evaluated. The response of apple plants to nutrient deficiency and the melatonin mechanism to alleviate nutrient stress were analyzed by combining ionome, transcriptome, and metabolome. The results showed that exogenous melatonin significantly alleviated the inhibitory effect of nutritional stress on the growth of apple plants by regulating stomatal morphology, improving antioxidant enzyme activity, promoting ion absorption, and utilizing and changing the absorption and distribution of minerals throughout the plant. The transcriptome results showed that melatonin alleviated nutrient stress and promoted nutrient absorption and utilization by regulating glutathione metabolism and upregulating some metal ion transport genes. The metabolome results indicated that levels of oxalic acid, L-ascorbic acid, anthocyanins (cyanidin-3-O-galactoside), lignans (lirioresinol A and syringaresinol), and melatonin significantly increased after exogenous melatonin was applied to plants under nutrient stress. These differentially expressed genes and the increase in beneficial metabolites may explain how melatonin alleviates nutrient stress in plants.

Fruit cracking in jujube is a major constraint on the sustainable development of the jujube industry. In this study, 60 mg L⁻¹ of 6-Benzylaminopurine (6-BA) was foliar-sprayed at the early fruit stage. Fruit cracking incidence was recorded during the green and white fruit periods, and these observations were integrated with transcriptomic and metabolomic analyses to explore the potential mechanisms by which 6-BA influences fruit cracking. The results showed that the fruit cracking in the treatment groups was 53% and 18% of that in the control group during the green period and the white period, respectively. In jujube peel, catalase (CAT) activity was significantly increased in the treated peel during both periods. In the peel metabolites, compounds belonging to the cytokinin (CTK) category exhibited significant accumulation in both periods. Transcriptomic analysis showed that differentially expressed genes (DEGs) were enriched in pathways related to starch and sucrose metabolism, plant hormone signal transduction, and cellular polysaccharide metabolism. These findings suggest that 6-BA treatment may alleviate jujube fruit cracking by enhancing antioxidant capacity, modulating hormone homeostasis, and upregulating genes associated with carbohydrate and cell wall metabolism.

Verticillium wilt, caused primarily by Verticillium dahliae and, in some hosts, V. albo-atrum, causes substantial yield losses in solanaceous crops. The disease is characterized by colonization of the vascular system, which can impair water transport and plant growth. Effective resistance therefore requires restricting vascular colonization while preserving vascular function and plant performance. Although considerable progress has been made in identifying resistance genes and defense responses, the molecular and physiological basis of Verticillium wilt resistance varies widely, and remains incompletely understood across solanaceous crops. Here, we summarize current knowledge of Verticillium wilt resistance in tomato, eggplant, potato, and pepper, focusing on vascular defense, immune signaling, lignification, and major resistance genes, loci, and quantitative genetic factors. We also discuss grafting-mediated resistance, highlighting resistant rootstocks and genetic resources, physiological and rhizosphere mechanisms of rootstock-mediated protection, and the potential roles of mobile signals in rootstock–scion communication. Furthermore, we examine the potential role of lignin remodeling as an interface between vascular defense and plant performance, while distinguishing disease-associated growth losses from potential defense-associated costs. We propose an integrative framework for evaluating resistance through pathogen restriction, vascular function, and agronomic performance, emphasizing that the relationships among these processes require further experimental validation. Finally, we outline future research priorities, including the identification and functional validation of resistance genes, quantitative assessment of vascular defense and its potential growth costs, and investigation of the causal contributions of grafting-associated signals and rhizosphere microbiomes. This review provides a framework for understanding Verticillium wilt resistance across solanaceous crops and highlights research priorities for developing durable resistance while maintaining crop productivity and quality.

Apple (Malus domestica Borkh.) is one of the most widely cultivated fruit crops globally. However, fruit sunburn, induced by excessive heat and intense solar radiation, poses a significant threat to apple production and fruit quality. Although numerous studies have investigated individual mitigation strategies, a comprehensive synthesis of sustainable management approaches and their practical applicability remains limited. This review provides an overview of advances in apple sunburn management, encompassing cultural practices such as canopy management and irrigation, physical protection methods including shade nets and evaporative cooling, protective treatments such as reflective sprays and particle films, and emerging approaches such as nanocoatings and gene editing. The review compares the reported effectiveness, physiological mechanisms, limitations, and practical considerations of these strategies. The evidence indicates that integrating complementary approaches may improve sunburn management, although their effectiveness varies with cultivar characteristics, climatic conditions, orchard practices, and resource availability. Accordingly, a practical framework is presented to guide strategy selection according to local sunburn risk, cultivar susceptibility, and economic feasibility. Future research priorities include improved risk-prediction models, standardized field trials, precision monitoring, and functional validation of candidate genes. This synthesis provides a basis for developing site-specific, economically feasible, and sustainable strategies to mitigate apple sunburn under changing climatic conditions.

Apple (Malus domestica Borkh.) is a major fruit crop of global economic importance, and China ranks first worldwide in both apple cultivation area and total production. With the large-scale renewal of aging orchards, apple replant disease (ARD) has become increasingly prevalent in major apple-producing regions. ARD is typically characterized by severe growth suppression, impaired root development, increased incidence of soil-borne diseases, and, in severe cases, seedling mortality. These symptoms substantially constrain orchard renewal, limit improvements in fruit yield and quality, and threaten the sustainable development of the apple industry. The etiology of ARD is complex and involves the synergistic interaction of three factors: soil microbial dysbiosis characterized by pathogen enrichment and the depletion of beneficial microorganisms; allelopathic autotoxicity caused by the accumulation of phenolic acids, especially phloridzin; and degraded soil physicochemical properties, including acidification, compaction, and nutrient imbalance. Current management strategies mainly include the use of ARD-tolerant rootstocks, microbial regulation, chemical and physical soil disinfection, and agronomic practices such as crop rotation and organic amendment application. Among these approaches, biological regulation mediated by beneficial rhizosphere and endophytic microorganisms has attracted increasing attention because of its environmental compatibility and sustainability. This review summarizes the occurrence patterns, regional characteristics, core pathogenic mechanisms, and integrated management strategies of ARD, with particular emphasis on the functional roles of rhizosphere and endophytic microbiomes in disease alleviation. The review provides a theoretical basis and practical reference for the development of green, efficient, and sustainable strategies for ARD control and apple orchard management.