DAZAP1 promotes OSCC progression via phase separation.

Oxygen consumption rate (OCR) and Extracellular acidification rate (ECAR) analysis in DAZAP1-overexpression and -knockdown Cal27 and HN6 cell lines.

CYTOR promotes DAZAP1 nuclear translocation and phase separation.

Alternative splicing of COX16 in OSCC cells.

DAZAP1 promotes OSCC cell migration, invasion and EMT progression.

Supplementary Materials and Methods

Targeting DAZAP1 suppresses tumor growth and metastasis in OSCC.

Polycomb group (PcG) proteins silence gene expression by depositing histone modifications such as H2Aub and H3K27me3, and this process is essential for maintaining cell type and tissue-specific gene expression patterns. However, the role of PcG proteins in regulating gene expression through H2Aub and H3K27me3 during maize kernel development remains poorly understood. Here, we characterize a maize miniature seed mutant, mn8, and identify the causal gene as ZmEMF1a, a plant-specific PcG protein. A mutation in ZmEMF1a significantly reduces kernel size and weight. Molecular analyses demonstrate that ZmEMF1a interacts with ZmRING1 (a PRC1 component) and ZmMSI1 (a PRC2 component), which are essential for the establishment of H2Aub and H3K27me3 modifications. Loss of ZmEMF1a leads to a significant reduction in genomic levels of both H2Aub and H3K27me3. Integrated ChIP-seq and RNA-seq analyses revealed that H2Aub is negatively correlated with gene expression in maize, contrasting with the positive correlation reported in Arabidopsis. Compared with wild-type endosperms, mn8 endosperms exhibit up-regulated expression of cell proliferation repressor homologs, such as ZmDA1, ZmBB1, ZmES22, ZmMADS8, and ZmMADS14. Concurrently, these loci show reduced levels of H3K27me3 or H2Aub modifications. These findings suggest that ZmEMF1a deficiency disrupts the deposition of H3K27me3 and H2Aub marks at cell division regulators. Our results indicate that ZmEMF1a plays a crucial role in regulating maize kernel development by maintaining H2Aub and H3K27me3 modification levels.

COX16 enhances invasion and mitochondrial respiration in OSCC cells.

The COX16 overexpression rescues the DAZAP1-knockdown induced phenotypes of OSCC cell lines.

Soil salinity is a severe threat to agriculture and plant growth. Under high salinity conditions, ammonium (NH4+) is the predominant inorganic nitrogen source used by plants due to limited nitrification. However, how ammonium shapes the plant response to salt stress remains a mystery. Here, we demonstrate that the growth of Arabidopsis (Arabidopsis thaliana) seedlings is less sensitive to salt stress when provided with ammonium instead of nitrate (NO3-), a response that is mediated by ammonium transporters (AMTs). We further show that the kinase SALT OVERLY SENSITIVE2 (SOS2) physically interacts with and activates AMT1;1 by directly phosphorylating the nonconserved serine residue Ser-450 in the C-terminal region. In agreement with the involvement of SOS2, ammonium uptake was lower in sos2 mutants grown under salt stress relative to the wild type. Moreover, AMT-mediated ammonium uptake enhanced salt-induced SOS2 kinase activity. Together, our study demonstrates that SOS2 activates AMT1;1 to fine-tune and maintain ammonium uptake and optimize the plant salt stress response.

Mini-Chromosome Maintenance 10 (MCM10) is essential for maintaining genome stability by facilitating DNA replication and repair across various organisms. While the role of MCM10 in DNA replication is well-established, its mechanism in DNA repair remains less understood. In this study, we demonstrate that loss of AtMCM10 function leads to increased DNA damage under genotoxic or salinity stress in Arabidopsis thaliana. Detailed analysis reveals that AtMCM10 works primarily downstream of ATM and is crucial for intermolecular homologous recombination (HR) mediated by synthesis-dependent strand annealing (SDSA) in response to DNA damage. Further cytological and biochemical analyses reveal that AtMCM10 possesses DNA annealing activity, colocalizes with the double-strand break (DSB) sites, and undergoes liquid-liquid phase separation (LLPS) upon DNA damage, facilitated by single strand DNA (ssDNA) in vitro. Altogether, our findings indicate that AtMCM10 acts as a single-strand DNA (ssDNA) annealing protein to promote SDSA-mediated intermolecular HR repair via LLPS in somatic cells upon DNA damage, providing new insights into the HR repair mechanisms.

The spur-type trait is an important breeding goal for apple (Malus × domestica Borkh.) cultivar, due to its advantages in yield and orchard mechanical management. MdWRKY50 encoding a transcription factor were identified to have dramatically lower expression in spur type. RNA interference of it leads to significantly shortened internodes in transgenic apple plants, while its overexpression resulted in opposite phenotype. The shortened internode of transgenic apple with RNA interfered MdWRKY50 was in good correlation with the bioactive gibberellin (GA) level. Furthermore, MdWRKY50 was proved to directly binds to the promoter of MdGA3ox, encoding a rate-limiting biosynthetase in GA biosynthesis, as confirmed by Chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) and Electrophoretic Mobility Shift Assay (EMSA). This binding up-regulated the expression of MdGA3ox. The low expression of MdWRKY50-MdGA3ox regulatory pathway is conserved across six spur-type apple cultivars in contrast to the high expressions across six standard-type apple cultivars. Our findings established a MdWRKY50-MdGA3ox module regulating GA-mediated internode elongation and coorelating with spur-type formation, which might contribute to the molecular breeding of spur-type cultivars adapted to high-density, mechanized apple orchards.

Global environmental change poses severe threats to agricultural ecosystems, with soil salinization emerging as a major constraint on crop productivity and sustainability. Salt stress disrupts plant physiological processesby inducing osmotic stress, ionic imbalance, and oxidative damage, thereby impairing growth and development. Therefore, elucidating the mechanisms underlying salt tolerance and developing salt-resistant crops have become critical for ensuring food security. This review synthesizes research from recent decades on plant responses to salt stress, with a focus on advances in the classical Salt Overly Sensitive signaling pathway and its central role in maintaining sodium homeostasis. We also discuss the emerging role of epigenetic regulation in mediating salt adaptation and the integration of salt-stress responses with other environmental cues under combinatorial stress conditions. Finally, we outline future research directions aimed at developing "environmentally intelligent" crops with enhanced salt tolerance through multidisciplinary strategies that combine quantitative biology, genetic engineering, and genome-editing technologies.

The calcineurin B-like protein (CBL)-CBL-interacting protein kinase (CIPK) Ca²⁺ sensors play crucial roles in the plant's response to drought stress. However, there have been few reports on the synergistic regulation of drought stress by CBL-CIPK and abscisic acid (ABA) core signaling components. In this study, we discovered that ZmCIPK33 positively regulates drought resistance in maize. ZmCIPK33 physically interacts with and is enhanced by phosphorylation from ZmSnRK2.10. Drought stress can activate ZmCIPK33, which is partially dependent on ZmSnRK2.10. ZmCIPK33 in combination with ZmSnRK2.10 can activate the slow anion channel ZmSLAC1 in Xenopus laevis oocytes independently of CBLs, whereas ZmCIPK33 or ZmSnRK2.10 alone is unable to do so. Furthermore, ZmCIPK33 phosphorylates ZmPP2C11 at Ser60, which leads to a reduction in the interaction between ZmPP2C11 and ZmEAR1 (the ortholog of Arabidopsis Enhancer of ABA co-Receptor 1) and weakens the phosphatase activity of ZmPP2C11, consequently, enhancing the activity of ZmSnRK2.10 in an in vitro assay and in the in-gel assay of the zmcipk33 mutant. Our findings provide novel insights into the molecular mechanisms underlying the reciprocal enhancement of Ca²⁺ and ABA signaling under drought stress in maize.

The plant-specific FYVE-domain-containing protein FYVE4, a component of the endosomal sorting complex required for transport III (ESCRT-III), participates in membrane protein sorting. However, the mechanism by which FYVE4 coordinates plant growth responses to environmental stress remains unclear. In this study, we reveal a novel function of FYVE4 in positively regulating plant salt resistance by modulating the Salt Overly Sensitive (SOS) signaling pathway. FYVE4 enhances SOS1 phosphorylation by promoting SOS1-SOS2 interactions during salt stress. Loss of FYVE4 reduces the SOS1-SOS2 association, leading to decreased SOS1 phosphorylation and increased plant sensitivity to salt stress. Notably, overexpression of SOS1 does not rescue the salt-sensitive phenotype of fyve4-1, whereas SOS2 overexpression does. In summary, our findings highlight the critical role of FYVE4 in promoting SOS1-SOS2 interactions to mitigate salt stress and reveal a previously unrecognized function of FYVE4 in abiotic stress responses, extending beyond its established role in membrane trafficking regulation.

Salt stress, especially the increasing secondary salt stress, severely compromises apple production worldwide. Mitigation of oxidative damage caused by salt stress is critical for salt tolerance in apple plants. However, it remains unclear how the salt signal triggers the excessive reactive oxygen species (ROS) mitigation system in apple. In this study, we identified a salt-induced gene MdGRF10 (encoding a 14-3-3 protein), whose overexpression conferred transgenic apple plants reduced oxidative damage and enhanced salt tolerance. Furthermore, a salt-activated receptor-like cytoplasmic kinase MdPBL34 was found to interact with and phosphorylate the C-terminal of MdGRF10. This phosphorylation promoted the interaction between MdGRF10 and a melatonin rate-limiting synthetase MdASMT1 (N-acetylserotonin methyltransferase). Its overexpression or knockdown by CRISPR/Cas9 in transgenic apple plants demonstrated that MdASMT1 is critical in melatonin-mediated ROS scavenging for salt tolerance. Their interaction stabilizes MdASMT1 by decreasing its ubiquitin-mediated degradation for increased melatonin level, decreased oxidative damage and therefore promoted salt tolerance. Our findings revealed that 14-3-3 protein could integrate the salt signal in a phosphorylation-dependent manner. Moreover, MdPBL34 was also identified for the first time to be involved in salt signaling. Our research uncovered a novel MdPBL34-MdGRF10-MdASMT1 regulatory module in response to salt stress in apple, which will contribute to the molecular breeding of melatonin-enriched salt-tolerant apple trees.

Soil salinization and alkalization are among the most critical abiotic stresses limiting global agricultural productivity. These environmental constraints affect more than a billion hectares of land worldwide and significantly compromise plant growth, development, and yield. The resulting reduction in arable land and food output poses an escalating threat to global food security and ecosystem sustainability. Understanding how plants sense, respond to, and adapt to salt-alkaline stress at the molecular, cellular, and physiological levels is thus a pressing research objective with profound implications for sustainable crop production and land utilization. Here, we provide a comprehensive overview of recent advances in elucidating the complex regulatory networks and cellular processes that underpin plant salt-alkaline stress responses. It highlights the mechanisms by which plants maintain ionic homeostasis, perceive extracellular signals, transduce those signals via intricate pathways, and reconfigure intracellular architecture to mitigate damage. A central focus is the Salt Overly Sensitive (SOS) signaling cascade, which plays a pivotal role in mediating Na+ extrusion across the plasma membrane. In particular, SOS1, a plasma membrane-localized Na+/H+ antiporter, has been extensively characterized as a key effector of Na+ efflux. Recent findings, however, reveal a novel intracellular role for SOS1, showing that it can be internalized and trafficked to the tonoplast under salt stress conditions. There, it facilitates vacuolar Na+ sequestration through a pathway regulated by the SOS2-FREE1 module, integrating signaling and membrane trafficking to enhance subcellular Na+ compartmentalization. Salt-alkaline stress also induces significant remodeling of cellular organelles, including vacuolar remodelling, mitochondrial turnover, and endoplasmic reticulum (ER) restructuring. These structural changes are essential for maintaining cellular integrity and metabolic balance during stress adaptation. Selective autophagy, especially mitophagy, is increasingly recognized as a key mechanism for the clearance of damaged organelles and the preservation of energy homeostasis under stress. Additionally, reactive oxygen species (ROS) and calcium (Ca2+) signaling operate as core components of the stress response network, integrating environmental stimuli with transcriptional reprogramming and the modulation of stress-induced programmed cell death pathways. The review also emphasizes the critical role of vesicular trafficking and membrane protein sorting in stress adaptation. In particular, the endosomal sorting complexes required for transport (ESCRT) system orchestrates the precise localization and recycling or degradation of membrane proteins, thereby influencing cellular ion transport capacity and signal transduction fidelity. Advances in genomics, including genome-wide association studies (GWAS), gene editing technologies such as CRISPR-Cas systems, and transcriptome-scale functional analyses, have facilitated the identification of key regulatory genes and alleles associated with salt-alkaline tolerance in various crops. These discoveries are being translated into molecular breeding strategies for developing elite germplasm with enhanced resilience. Looking ahead, integrated approaches combining multi-stress regulation, subcellular precision engineering, and synthetic biology are poised to drive the next generation of salt-alkaline tolerant crops, contributing to the sustainable use of marginal lands and ensuring long-term agricultural stability.

Nitrogen (N) is an essential macronutrient for plant development and, ultimately, yield. Identifying the genetic components and mechanisms underlying N use efficiency in maize (Zea mays L.) is thus of great importance. Nitrate (NO3-) is the preferred inorganic N source in maize. Here we performed a genome-wide association study of shoot NO3- accumulation in maize seedlings grown under low-NO3- conditions, identifying the ferredoxin family gene ZmFd4 as a major contributor to this trait. ZmFd4 interacts and co-localizes with nitrite reductases (ZmNiRs) in chloroplasts to promote their enzymatic activity. Furthermore, ZmFd4 forms a high-affinity heterodimer with its closest paralogue, ZmFd9, in a NO3--sensitive manner. Although ZmFd4 exerts similar biochemical functions as ZmFd9, ZmFd4 and ZmFd9 interaction limits their ability to associate with ZmNiRs and stimulate their activity. Knockout lines for ZmFd4 with decreased NO3- contents exhibit more efficient NO3- assimilation, and field experiments show consistently improved N utilization and grain yield under N-deficient conditions. Our work thus provides molecular and mechanistic insights into the natural variation in N utilization, instrumental for genetic improvement of yield in maize and, potentially, in other crops.