沈阳农业大学

Shelf-life is a key indicator for measuring the postharvest quality and commercial value of fruits. During the shelf-life period, the flavor and texture of Nanguo pears undergo rapid changes. While single near-infrared spectroscopy (NIRS) technology can capture variations in the chemical composition of Nanguo pears, it struggles to accurately characterize their physical texture. The study constructed a dual-modal shelf-life evaluation system for Nanguo pears that integrates NIRS and electrochemical impedance spectroscopy (EIS). Using a support vector machine (SVM) classifier, a shelf-life grading model for Nanguo pears was established. The results demonstrated that the dual-modal fusion model achieved an overall grading accuracy of 95.8% on an independent test set across four shelf-life stages (unripe, partially ripe, ripe, and overripe). This model significantly outperformed single-modal models based solely on NIRS (87.5% accuracy) or EIS (84.2% accuracy). The dual-modal fusion strategy effectively eliminates the detection blind spots of single sensing technologies. Spectral information ensures high accuracy in identifying early ripeness stages, while EIS reflects the physical texture and cell membrane damage of fruits in the overripe stage, thereby compensating for the limitations of NIRS in late-stage physical assessment. The dual-modal fusion approach offers a novel non-destructive testing pathway for precise shelf-life grading of Nanguo pears.

To mitigate the storage intolerance problem of Actinidia arguta, clarify the sources of suitable male pollen. This study investigates the effects of different male pollens on the storage quality of late-maturing A. arguta and establishes a storage evaluation system. The study uses four late-maturing resources and four types of pollen for pollination experiments, through sensory and flavor analysis, the compatible male plants for each resource are selected as SNWS1 ×XZ1, SNWS2 ×XZ1, SNWS3 ×XZ2, and SNWS4 ×XZ1. The fruit from the compatible combinations are stored at 25 °C and 2 °C, and their quality changes are systematically analyzed. Based on correlation analysis, principal component analysis, the CRITIC method, and grey relational analysis, a comprehensive evaluation model for storage quality was established. The results shows that a weighted grey relational model is constructed based on six core indicators: rot rate, relative conductivity, vitamin C, catalase enzyme, chromatic aberration, and flavone. The evaluation indicates that SNWS4 has the best quality in the early storage period, SNWS2 and SNWS3 perform better in the middle and late stages, while SNWS1 is least suitable. This study provides a theoretical basis for the selection of pollination combinations and postharvest storage management of late-maturing A. arguta.

Abscisic acid (ABA) promotes climacteric ethylene biosynthesis and fruit ripening, but the underlying regulatory mechanisms remain unclear. Here, exogenous ABA treatment enhanced ethylene production and induced the expression of MdACS1 and MdACO1 in postharvest apple fruit. Transcriptome analysis identified MdZF-HD11 as an ABA-induced transcription factor that directly bound to the promoters of MdACS1 and MdACO1 and activated their transcription. In contrast, MdWRKY28, whose expression was repressed by ABA, directly inhibited the transcription of MdACS1 and MdACO1, thereby negatively regulating ethylene biosynthesis. Importantly, MdZF-HD11 interacted with MdWRKY28 and attenuated its transcriptional repression activity. Moreover, MdWRKY28 directly suppressed MdZF-HD11 transcription, whereas their interaction weakened this repression, forming a positive feedback loop that amplified downstream ethylene biosynthesis. Taken together, our findings elucidate an ABA-mediated MdZF-HD11/MdWRKY28 regulatory module that promotes ethylene biosynthesis in apple fruit, providing important mechanistic insights into the crosstalk between ABA and ethylene signaling in climacteric fruit ripening.

Broccoli is prone to rapid postharvest senescence and quality deterioration. Strigolactones (SLs) can mitigate postharvest quality deterioration by coordinating multiple physiological and biochemical processes. However, studies investigating the postharvest effects of SLs on broccoli remain limited. This study investigated the effects of GR24, a synthetic SL analog, and Tis-108, an SL biosynthesis inhibitor, on broccoli during storage using integrated physicochemical and transcriptomic analyses. GR24 (2 μM) delayed senescence by maintaining stomatal function, chloroplast morphology, and cell wall integrity while preserving texture, bioactive compounds, color attributes, and water content. GR24 reduced membrane lipid peroxidation and enhanced antioxidant capacity, as reflected by reduced malondialdehyde accumulation, maintained 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity, modulated lignin and polyamine metabolism, enhanced phenylpropanoid metabolism and antioxidant enzyme activities, suppressed ethylene release, increased abscisic acid levels, and decreased jasmonic acid levels in postharvest broccoli. Transcriptome analysis identified key pathways, including starch and sucrose metabolism, flavonoid biosynthesis, phenylpropanoid biosynthesis, the plant MAPK signaling pathway, and pentose and glucuronate interconversions. Six candidate transcription factors (ERF95, bHLH3, bHLH22, bZIP21, WRKY6, and WRKY8) were identified. Conversely, Tis-108 (3 μM) aggravated senescence at both the physiological and transcriptional levels. These findings define an SL-associated regulatory framework underlying the GR24-mediated delay of postharvest senescence in broccoli and provide experimental evidence to inform future research on vegetable senescence management.

Ethylene is the key hormone triggering ripening and senescence in climacteric fruit, while postharvest heat shock treatment is an effective physical strategy to suppress ethylene biosynthesis. However, the transcriptional regulatory network underlying heat-induced inhibition of ethylene production in apple remains largely unclear. In this study, we found that a 72 h heat shock treatment at 38 °C significantly suppressed ethylene biosynthesis and delayed senescence in ‘Golden Delicious’ apples, which was closely associated with the downregulation of key ethylene biosynthesis genes (MdACS1 and MdACO1) and ethylene biosynthesis activator MdERF3. We identified a heat shock transcription factor, MdHSFB3b, strongly induced by 38 °C heat shock treatment. MdHSFB3b directly binds to the promoters of MdACS1 and MdACO1 and represses their transcription. Moreover, MdHSFB3b interacts with the transcriptional activator MdERF3, antagonizing its activation of MdACS1. Transient overexpression of MdHSFB3b in apple fruit significantly reduced MdACS1 and MdACO1 transcript levels and ethylene production, thereby delaying fruit ripening, whereas transient silencing of MdHSFB3b increased MdACS1 and MdACO1 transcription and ethylene production, accelerating fruit ripening. Collectively, our results demonstrate that MdHSFB3b functions via a dual mechanism: it directly represses ethylene biosynthesis genes and interferes with MdERF3-mediated transcriptional activation, ultimately inhibiting postharvest ethylene production in apple. This study elucidates the gene regulatory network underlying heat shock-induced suppression of ethylene biosynthesis and provides potential molecular targets for extending apple shelf life.