The ubiquitination pathway has been found to regulate plant responses to environmental stress. However, the role of E3 ubiquitin ligase in desiccation tolerant moss has not yet been elucidated. Previous research has shown that the abscisic acid (ABA) signaling factor ScABI3 can significantly increase desiccation tolerance and reduce ABA sensitivity in the desert moss Syntrichia caninervis. In this study, we identified a RING-type E3 ubiquitin ligase, ScPRT1, and showed that ScABI3 can directly interact with ScPRT1 in vitro and in vivo. Furthermore, we found that the high expression of ScPRT1 can interfere with the transcription of ScABI3 under ABA treatment. Therefore, we speculate that ScPRT1 may degrade ScABI3 through the ubiquitin-26S proteasome system and participate in ABA-dependent signaling in response to ABA-insensitivity or desiccation tolerance in S. caninervis. The findings from our study may enrich our knowledge of the role of E3 ubiquitin ligase in desiccation tolerance and lay a theoretical foundation for an in-depth study of the relationship between ubiquitination modification and ABA signal transduction under environmental stress.

Autophagy is a conserved degradation pathway essential for cellular homeostasis in plants. Selective autophagy confers cargo specificity through receptors, among which NEIGHBOR OF BRCA1 GENE1 (NBR1) is one of the best-characterized. NBR1 mediates the selective turnover of ubiquitinated or stress-damaged cargoes, including protein aggregates and damaged organelles, by linking them to ATG8-decorated autophagosomes via its AIM and UBA domains. This process supports proteostasis, plant development, and adaptation to abiotic stresses, including heat, drought, chilling, salinity, and heavy metals, as well as biotic stresses from bacteria, fungi, viruses, and oomycetes. In this review, we summarize current advances in understanding NBR1 structure, evolutionary conservation, and cargo recognition mechanisms, and highlight its interplay with phytohormone signaling and the ubiquitin–proteasome system (UPS) in shaping plant growth and stress resilience.

Fruit shape diversity in melon is governed by complex genetic networks, with ethylene biosynthesis playing a pivotal yet poorly characterized role. In this study, we identified a rare CmACS7^{A57V/frameshift} double mutant through fine mapping of the fsq2 locus. Ethylene-mediated ovary growth regulation has been completely lost in the CmACS7^{A57V/frameshift} double mutant, driving a transition from elongated to spherical fruit. Transcriptome analysis was performed to clarify the core role of CmACS7 in the ethylene signaling pathway. The loss of CmACS7 function regulates key genes in the ethylene responsive factor, cytokinin signaling pathway, and auxin-related genes, resulting in an imbalance in hormone levels. This imbalance directly affects the coordination of cell proliferation and expansion and ultimately determines the fruit morphology. A genetic diversity analysis of public melon germplasm resources indicated that while the CmACS7^{A57V/frameshift} mutation accounts for only 0.5% of the germplasm, it is strongly correlated with the round fruit phenotype and is important for breeding in Xinjiang. The results of this study suggest that CmACS7^{A57V/frameshift} could be used as a molecular marker to accelerate the breeding of melon varieties with excellent fruit morphology and, at the same time, reveal the coevolutionary significance of this gene in the domestication of Cucurbitaceae crops.

Verticillium dahliae is a devastating soil-borne fungal pathogen that causes severe yield losses in melon (Cucumis melo L.) and other crops. Identifying novel resistance genes is crucial for sustainable disease management. In this study, we characterized the function of CmVQ23, a candidate gene previously identified through QTL mapping, in mediating defense against V. dahliae using heterologous expression in Arabidopsis thaliana. Subcellular localization assays revealed that the CmVQ23-eGFP fusion protein predominantly localized to the nucleus, consistent with its predicted role as a co-factor of transcription factor. Upon V. dahliae inoculation, CmVQ23-overexpressing Arabidopsis lines exhibited significantly reduced disease indices and restricted fungal proliferation compared with wild-type and mutant plants, although these lines displayed altered vegetative growth, including delayed bolting and reduced plant height. Mechanistically, CmVQ23 overexpression promoted reactive oxygen species (ROS) accumulation and hypersensitive response (HR)-mediated cell death at infection sites, as evidenced by intensified DAB and trypan blue staining. Furthermore, transgenic lines maintained higher photosynthetic efficiency, enhanced antioxidant enzyme activities, and increased lignin deposition via upregulation of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). Notably, CmVQ23 overexpression markedly upregulated both salicylic acid (SA)- and jasmonic acid/ethylene (JA/ET)-responsive marker genes, including AtPR1, AtPR2, AtPR5, AtPAD4, AtPDF1.2, and AtVSP2 upon infection. Collectively, these findings demonstrate that CmVQ23 functions as a positive regulator of resistance to Verticillium dahliae by orchestrating ROS/HR-mediated cell death, antioxidant defense, phenylpropanoid pathway activation, and phytohormone signaling crosstalk, offering a promising genetic resource for improving Verticillium wilt resistance in crops.

Pomegranate peel, a rich source of polyphenols, is largely underutilized. To address the challenges of high polarity, poor solubility, and instability of these bioactive compounds, a green ultrasound-enzyme combined extraction system was developed for sour pomegranate (Punica granatum L.) peels from Xinjiang, China. Process parameters were optimized via single-factor tests, Plackett–Burman design, and Box–Behnken response surface methodology. The optimal conditions (cellulase:pectinase = 7:3, enzyme concentration 2.5%, enzymatic hydrolysis at 40 °C for 60 min, followed by ultrasound at 50 °C for 27 min with a solid–liquid ratio of 1:20) yielded a total polyphenol content of 216.2 mg/g, which closely matched the predicted value (0.76% deviation). This combined approach significantly outperformed individual methods in polyphenol yield and antioxidant activity. HPLC identified punicalagin, ellagic acid, gallic acid, catechin, and chlorogenic acid as major phenolics. The extract exhibited antibacterial activity against the two tested bacterial strains, with a minimum inhibitory concentration of 12.5 mg/mL against both E. coli and S. aureus. This efficient, eco-friendly process offers a promising strategy for valorizing pomegranate peel waste.