Search Results (195)

Actinidia arguta possesses great commercial value as an economically important fruit crop, which accumulates abundant nutrients and bioactive components with medicinal potential. However, adverse abiotic environments, especially cold and drought stress, severely restrict its vegetative growth, reproductive development and fruit yield. Numerous studies have established MYB transcription factors as core regulators of plant abiotic stress adaptation. Here, we cloned AaMYB4 from A. arguta ‘Fenglü’ and systematically characterized its function in cold and drought tolerance. AaMYB4 encodes a 241-amino-acid R2R3-MYB protein localized to the nucleus, with highest expression in stems and young leaves. Its transcription is markedly induced by cold, drought and abscisic acid (ABA) within 24 h with a single peak expression pattern. Heterologous overexpression of AaMYB4 in Arabidopsis alleviated cold-induced oxidative damage, accompanied by reduced malondialdehyde (MDA) and reactive oxygen species (ROS) accumulation as well as increased proline contents and enhanced superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. Virus-induced gene silencing (VIGS)-mediated silencing of AaMYB4 impaired cold tolerance in Actinidia arguta seedlings, while stable AaMYB4 overexpression significantly improved plant survival and physiological performance under cold and drought conditions, concurrent with attenuated ROS accumulation. At the transcriptional level, AaMYB4 overexpression is positively associated with elevated transcript levels of stress marker genes in the ABA signaling and ICE1-CBF-COR pathways. This study lays a theoretical foundation for exploring abiotic stress tolerance mechanisms and conducting stress-resistant molecular breeding in A. arguta. Full article

SARS-CoV-2 infection leads to extrapulmonary complications in multiple organs, including the brain, both in the short-term and long-term. The neurological manifestation of SARS-CoV-2 infection ranges from benign signs like loss of smell and loss of taste to severe complications like encephalitis, stroke, and exacerbation of Alzheimer’s disease (AD) progression. Pericytes are mural cells of the brain vasculature that help maintain the blood–brain barrier (BBB), regulate cerebral blood flow (CBF), modulate neuroinflammation, and clear toxic materials, including amyloid beta. Pericytes express ACE2, the receptor for SARS-CoV-2, and therefore may be targeted by either direct virus infection or virus-induced inflammatory cytokines induced by the virus in the brain. To further study the effects of SARS-CoV-2 on pericytes and BBB integrity, the long-term effects of SARS-CoV-2 infection on brain pericytes, inflammation, and other neuropathological complications were analyzed in mice. K18 (human ACE2 transgenic) mice were infected with 10³ PFU of SARS-CoV-2 (delta strain), and the brains were analyzed at 6, 14, and 30 days post-infection (dpi). A significant reduction in the weight of infected mice was observed by 6 dpi. Viral nucleocapsid protein and infectious SARS-CoV-2 were observed in the brains of all mice by 6 dpi, and in some mice by 14 dpi, but not at 30 dpi. This observation suggests viral neurotropism with subsequent clearance at later timepoints. Despite virus clearance, the levels of inflammatory mediators, including TNF-α and IFN-γ were significantly elevated up to 30 dpi. We also observed a significant reduction in the level of brain pericytes by 14 dpi up to 30 dpi. Importantly, an increase was observed in the level of Friend Leukemia Integration 1 (FLI-1), a transcription factor known to promote pericyte cell death, from 14 dpi up to 30 dpi. The level of amyloid beta 1–42 was elevated in the brain of infected mice at 6 dpi, and this was maintained up to 30 dpi, and there was a decrease in neuronal density from 14 to 30 dpi. Furthermore, we observed an increased expression of Alzheimer’s disease (AD)-associated genes like PSEN1, BACE1, and APP. Furthermore, there was increased activation of several neurodegenerative pathways, including “G alpha (z) signaling pathway”, “Apelin muscle signaling pathway”, and “G beta-gamma (Gβγ) signaling”, in the brains of infected mice compared to control mice. Collectively, the observed neuropathology and unique molecular markers of neurodegenerative disease progression provide a novel mechanism by which COVID-19 may promote dementia/AD by contributing to pericyte loss and BBB dysfunction during infection. Full article

Low-temperature stress severely limits early-spring melon (Cucumis melo L.) production. However, the regulatory roles of NAC transcription factors in melon responses to abiotic stress remain insufficiently understood. In this study, the melon cultivar ‘Xizhoumi No. 17’ was used as the experimental material, and an Agrobacterium-mediated root transformation system was employed to generate CmNAC29-overexpressing and empty-vector control plants. Phenotypic analysis, physiological measurements, transcriptome sequencing, and molecular interaction assays were performed to systematically investigate the regulatory mechanism by which CmNAC29 mediates chilling tolerance in melon roots. The results showed that CmNAC29 overexpression significantly alleviated cold stress-induced growth inhibition in melon seedlings, reduced membrane lipid peroxidation, and enhanced antioxidant enzyme activities and proline accumulation. Transcriptome analysis revealed that differentially expressed genes associated with CmNAC29 overexpression were significantly enriched in functional categories related to oxidoreductase activity. Further validation showed that CmNAC29 upregulated the expression of antioxidant enzyme genes, the key proline biosynthesis gene CmP5CS1, and core components of the Inducer of CBF Expression–C-repeat Binding Factor–Cold-Regulated pathway. Molecular assays confirmed that CmNAC29 possesses transcriptional activation activity and directly binds to the promoters of CmP5CS1-1 and CmCOR413 by recognizing NAC-binding sites, thereby activating their transcription. Taken together, these findings demonstrate that CmNAC29 positively regulates chilling tolerance in melon seedlings by coordinately enhancing antioxidant defense, osmotic adjustment, and cold signal transduction. This study provides an important genetic resource and theoretical basis for the molecular breeding of cold-tolerant melon cultivars. Full article

Abiotic stresses severely restrict plant growth, development, and crop yield. Histone modification functions as a key epigenetic regulator in plant stress adaptation. This review systematically summarizes the major types of histone modifications (e.g., acetylation, methylation) and their catalytic enzyme systems. It clarifies the regulatory patterns of chromatin remodeling and gene expression under diverse abiotic stress conditions, like extreme temperature changes, persistent drought, elevated salinity, and heavy metal exposure, and reveals the crosstalk networks between histone modifications and ABA, CBF/DREB, and ROS signaling pathways. It also discusses the transgenerational inheritance of stress-induced histone modification variations and their molecular basis, and introduces the application of CRISPR/Cas9 and dCas9-based epigenetic editing in improving crop stress resistance. Currently, research on histone modification in plateau crops remains fragmented: studies mostly focus on single stress rather than combined multiple abiotic stresses, lack tissue-specific epigenetic regulatory maps for native plateau plants, and the field application of epigenetic breeding technologies is seriously insufficient. Considering the compound stresses, including low temperature, drought, salinization, and heavy metals, on the Qinghai–Tibet Plateau, this review identifies current research gaps, such as tissue specificity, multi-stress crosstalk, and field application, and proposes future directions, including multi-omics analysis, stress adaptation mechanisms of plateau plants, and precise epigenetic breeding. Overall, this review fills the research gap of systematic collation on histone-mediated stress tolerance epigenetics under plateau combined abiotic stresses, and provides a theoretical reference for epigenetic research on plant stress resistance and for the improvement of plateau crops. Full article

Identifying cold-resistance genes is essential for improving the ability of apples (Malus × domestica) to tolerate low temperatures, as cold stress significantly limits their growth and productivity. The MdWRKY31 gene was cloned from apple, and its sequence characteristics, expression pattern, and biological function were systematically investigated. Bioinformatic analysis indicated that MdWRKY31 belongs to the group II WRKY transcription factors and is localized in the nucleus. Expression analysis revealed that MdWRKY31 transcript levels were markedly upregulated under low-temperature stress. To further explore its function, MdWRKY31 was heterologously overexpressed in tomato (Solanum lycopersicum). Following low-temperature treatment, transgenic tomato plants exhibited significantly reduced accumulation of reactive oxygen species, markedly enhanced activities of antioxidant enzymes (SOD, POD, and CAT), increased contents of proline and soluble protein, and a notable decrease in malondialdehyde levels. Additionally, transcript levels of SlCBF1, SlCBF2, SlCBF3, SlICE1, along with the ABA signaling-related genes SlNCED1 and SlABI5, were markedly elevated. Further molecular docking showed that the MdWRKY31 protein has strong binding affinity to the W-box elements in the promoters of SlCBF1 suggesting that it may regulate the expression of these genes through direct protein–DNA interactions. These findings indicate that MdWRKY31 improves plant cold tolerance by CBF-dependent pathways to modulate antioxidant defenses and osmotic balance. These findings identify candidate genetic resources for breeding cold-resistant apple cultivation. Full article

Background/Objectives: Snow Chrysanthemum (Coreopsis tinctoria Nutt.), a traditional medicinal and edible plant rich in flavonoids (TFSC) with antihypertensive and neuroprotective activities, has unclear effects and mechanisms on vascular dementia (VaD) comorbid with hypertension, a key risk factor accelerating VaD. This study aimed to investigate TFSC’s ameliorative effects on cognitive impairment in hypertensive VaD rats and elucidate its holistic therapeutic mechanisms. Methods: Spontaneously hypertensive rats (SHRs) with unilateral common carotid artery ligation were used to establish the hypertensive VaD model. TFSC was intragastrically administered for 11 weeks. Systolic blood pressure (BP) and cerebral blood flow (CBF) were monitored; cognitive function was assessed via open field, novel object recognition and Morris water maze tests. Histopathological changes were evaluated by H&E and Nissl staining, serum oxidative stress and inflammatory markers were measured, and hippocampal transcriptome sequencing plus RT-qPCR was performed to identify key pathways and genes. Results: The chemical profile of TFSC was characterized, showing a total flavonoid content of 84.96%; 49 compounds were identified, 39 of which were flavonoids. TFSC reduced BP, improved CBF, alleviated cognitive dysfunction and neuronal damage, enhanced antioxidant capacity (increased SOD, CAT, GSH; decreased ROS), and exerted anti-inflammatory effects (reduced TNF-α, IL-1β, IL-6, Ang-II). It modulated multiple pathways, with the PI3K-Akt and MAPK pathways enriched, and validated key differentially expressed genes. Conclusions: This study provides preliminary evidence for the holistic therapeutic potential of TFSC against hypertensive VaD. With integrated vascular regulatory and neuroprotective effects, TFSC serves as a promising candidate for VaD by targeting both vascular risk factors and neuropathological damage. Full article

Winter rapeseed (Brassica rapa L.) is an important crop for vegetable oil production in China. However, its productivity is frequently threatened by severe cold waves during winter. To investigate the role of the microtubule cytoskeleton in cold adaptation of winter rapeseed, a microtubule stabilizer paclitaxel (Tax) and a microtubule depolymerizer colchicine (Col) were sprayed on winter rapeseed and transgenic proBrAFP1 Arabidopsis, respectively. The mRNA levels of cold-induced genes, along with cell membrane stability, antioxidant enzyme activities, and hormone levels were assessed under cold stresses of 4 °C and −4 °C. The results showed that low temperature significantly activated the proBrAFP1 promoter activity and increased the mRNA levels of core cold signaling pathway genes, such as C-REPEAT BINDING FACTORS (CBFs), Cyclic Nucleotide-Gated Channel (CNGC), OPEN STOMATA 1 (OST1) and Inducer of CBF EXPRESSION 1 (ICE1). Notably, under low-temperature stress, exogenous application of the microtubule stabilizer Tax markedly suppressed proBrAFP1-driven reporter activity in transgenic Arabidopsis, with consistent inhibition observed across both stem and leaf tissues; meanwhile, the Tax application alleviated reactive oxygen species (ROS) accumulation and mitigated membrane damage. In contrast, under the same low-temperature stress, the Col treatment exacerbated oxidative stress, enhanced lipid peroxidation, and elevated membrane damage. Collectively, these findings establish that microtubule regulators play indispensable roles in the cold stress response of winter rapeseed. It provides new insights into the mechanism by which plant microtubule cytoskeleton regulators mediate the cold response. Full article

The jujube (Ziziphus jujuba Mill.) is a significant economic fruit tree, valued for its nutritional and medicinal properties. However, advances in functional genomics are hindered by the lack of an efficient transformation system. To overcome the limitations of conventional explant, we established a fruit-pulp-derived, callus-based Agrobacterium-mediated transformation system using fruit-pulp harvested 50 days after pollination. Through orthogonal experimental design, 6-benzylaminopurine and 2,4-dichlorophenoxyacetic acid were identified as key regulators for inducing high-quality, friable callus in two jujube genotypes, ‘JZ60’ and ‘LWCZ’. This system revealed significant genotype-specific variation in auxin requirements for callus proliferation and in differential antibiotic sensitivity. Transformation efficiency, as evaluated by fluorescence screening, was primarily determined by acetosyringone concentration and the binary vector architecture. The results revealed that the compact pCY (kanamycin resistance) vector achieved higher transformation efficiency (up to 77.8%) than pCAMBIA1301, whereas the pCAMBIA1301 (hygromycin resistance) vector enabled more uniform transgene expression. Integration and expression of the ZjCBF3 transgene were confirmed by polymerase chain reaction (PCR), reverse transcription quantitative PCR, and green fluorescent protein fluorescence assays. This study established a fruit-pulp-based callus transformation system for jujube, providing a rapid platform for its functional genomic studies. Full article

Nuclear Factor Y (NF-Y) transcription factors play pivotal roles in plant adaptation to abiotic stress, yet their genomic landscape and functional mechanisms in cabbage (Brassica oleracea var. capitata L.) remain underexplored. Here, we performed a genome-wide identification of the NF-Ys in cabbage, identifying 53 BoNF-Ys classified into three subfamilies: 20 BoNF-YAs, 22 BoNF-YBs, and 11 BoNF-YCs. Phylogenetic clustering revealed evolutionary conservation with their Arabidopsis orthologs. Domain analysis revealed that all BoNF-YA members contain the CBF_NF-YA domain, while all BoNF-YB and BoNF-YC members possess the CBFD_NFYB_HMF conserved domain. The BoNF-Y genes were named according to their chromosomal locations. Bioinformatic analysis showed that BoNF-Y proteins range in size from 131 to 642 amino acids, with molecular weights of 14.82–73.18 kDa, theoretical pI values of 4.57–9.96, instability indices between 33.02 and 73.48, aliphatic indices of 45.3–86.26, and grand average of hydropathicity (GRAVY) values ranging from −1.139 to −0.367. Promoter cis-element profiling uncovered stress- and hormone-responsive motifs, including abscisic acid-responsive elements (ABREs), TC-rich repeats, and ethylene-responsive elements (EREs). RNA sequencing (RNA-seq) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) conducted under salt stress (256 mM) identified three salt-responsive candidate genes (BoNF-YA14, BoNF-YB9, and BoNF-YC8). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses highlighted significantly expressed genes’ roles in MAPK signaling, proline metabolism, and phytohormone transduction pathways. This study conducted a comprehensive survey of the BoNF-Y gene family in cabbage. It could serve as a theoretical foundation for further functional identification and utilization of BoNF-Y family members and their role in the interaction between cabbage and salt stress. Full article

Longan (Dimocarpus longan Lour.) is highly sensitive to low temperature, which severely restricts its cultivation and industrial development. MYB transcription factors serve as key regulators in plant responses to cold stress. In this study, an R2R3-MYB gene DlMYB108 was cloned from ‘Shixia’ longan. Sequence analysis showed that DlMYB108 contains two typical MYB repeats and shares high homology with cold-responsive MYB108 proteins from other plants. Expression pattern analysis revealed that DlMYB108 is highly expressed in young leaves, which are more sensitive to cold stress, and is significantly induced by low-temperature treatment. Subcellular localization and transcriptional activation assays confirmed that DlMYB108 is a nuclear-localized transcriptional activator. Yeast one-hybrid and dual-luciferase assays demonstrated that DlMYB108 specifically binds to the promoters of DlCBF2 and DlCBF3 and activates their transcription. Heterologous expression of DlMYB108 in Arabidopsis significantly enhanced cold tolerance, accompanied by reduced ion leakage, malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation, as well as upregulated expression of CBF and cold-responsive genes. Collectively, DlMYB108 positively regulates longan cold tolerance through activating DlCBF2 and DlCBF3 expression, providing a valuable candidate gene for cold-tolerant longan breeding. Full article

Potato tubers can be dormant for 1–15 weeks after harvest, and the germination of tuber eye-buds is suppressed by cold. Genetic mechanisms regulating bud dormancy at low temperatures are not completely understood. We performed RNA-seq to compare gene expression in tubers after 0.5, 3.5, and 6.5 months of cold storage. Differentially expressed genes (DEGs) in non-dormant (3.5/6.5 months) vs. dormant (0.5 months) tubers were associated with transcriptional and translational activation, cell growth, metabolism, hormonal signaling, meristem development, dormancy break, and reproduction, confirming the non-dormant state of the meristem in the middle of storage. DEGs encoding transcription factors (TFs) (CBF1, FLC, SVP, HY5, GI, CO, FT, SOC1, CDF1, POTM1) were associated with the regulation of dormancy, flowering, and tuberization. TF DEGs upregulated (78) or downregulated (224) over four times in non-dormant vs. dormant tubers are considered potential coordinators of the endo- to non-dormancy transition and upcoming tuber sprouting during cold storage. RT-qPCR analysis of non-dormant and germinating buds revealed the upregulation of tuberigens (StSP3D, StFTL1-1, StFTL1-2), anti-tuberigens (StSP5G-like), and TF genes positively associated with tuberization or flowering/germination (StFDL1, StFDL, StCDF1, StCO-like). Our results should further investigation of the mechanisms underlying tuber meristem dormancy release and sprouting during long-term cold storage. Full article

Designing provably safe controllers for high-dimensional nonlinear systems with formal guarantees represents a fundamental challenge in control theory. While control barrier functions (CBFs) provide safety certificates through forward invariance, manually crafting these barriers for complex systems becomes intractable. Neural network approximation offers expressiveness but traditionally lacks formal guarantees on approximation error and Lipschitz continuity essential for safety-critical applications. This work establishes rigorous theoretical foundations for learned barrier functions through explicit probabilistic bounds relating neural approximation error to safety failure probability. The framework integrates Lipschitz-constrained neural networks trained via PAC learning within multi-objective model predictive control. Three principal results emerge: a probabilistic forward invariance theorem establishing $\mathbb{P}\left(\mathrm{violation}\right)\le T{\delta }_{\mathrm{local}}+exp(-h_{min}^2/\left(2L^{2}T{\sigma }^2\right))$, explicitly connecting network parameters to failure probability; sample complexity analysis proving $\mathcal{O}\left(N^{-1/4}\right)$ safe set expansion; and computational complexity bounds of $\mathcal{O}\left(H^3{m}^3\right)$ enabling 50 Hz real-time control. An experimental validation across 648,000 time steps demonstrates a 99.8% success rate with zero violations, a measured approximation error of $\sigma =0.047$ m, a matching theoretical bound of $\sigma \le 0.05$ m, and a 16.2 ms average solution time. The framework achieves a 52% conservatism reduction compared to manual barriers and a 21% improvement in multi-objective Pareto hypervolume while maintaining formal safety guarantees. Full article

When kept at a low temperature, yellow melons are prone to chilling injury. It is widely known that applying putrescine (Put) after harvest can prevent chilling harm in fruit. The best dosage of Put for treating yellow melon remains unknown, and the underlying mechanisms are not well understood. This study aimed to investigate the effects of exogenous putrescine application on chilling injury in melons and to elucidate the underlying physiological and molecular mechanisms involved. In this study, melons were treated with various concentrations of Put (0, 1, 2, and 4 mM), and the phenotype, chilling injury index, endogenous polyamine content, activities of crucial enzymes, and expression levels of associated genes (CmADC, CmODC, CmSAMDC1-4, CmSPDS1-2, CmSPMS1-2, and CmCBF1-4) were measured during storage. In our study on yellow melon, we found that treatment with 2 mM Put optimally alleviated chilling injury. This effect was achieved by enhancing the activities of ADC, AIH, CPA, ODC, SAMDC, DAP, and PAO, thereby regulating the endogenous levels of Put, Spd, and Spm. Furthermore, Put mainly impacted the expression of CmCBFs, which might help regulate downstream cold-inducible genes, leading to the improvement of tolerance in yellow melon fruit. Exogenous Put enhances melon chilling tolerance by activating endogenous polyamine biosynthesis and the CBF signaling pathway. This provides an effective strategy for post-harvest preservation of melons and might serve as a guide for future research into the mechanism involved in Put-induced chilling tolerance in horticulture crops. Full article

Spring frost poses a major threat to grape-producing regions, severely reducing grape yield and quality. Grafting rootstocks is an effective strategy for enhancing scion resistance to spring frost and mitigating damage. In this study, the two wine grape cultivars (‘Cabernet Sauvignon’ and ‘Chardonnay’) grafted onto three rootstocks (‘Beta’, ‘Kober 5BB’, and ‘3309 Couderc’) were evaluated for their spring frost resistance on one-year-old vines. The scion–rootstock combinations exhibited significantly less photosynthetic impairment under frost stress compared with own-rooted vines. Rootstock also showed lower levels of proline accumulation in the roots and APX activities in the leaves under frost conditions. Compared with own-rooted vines, VvCBF1 gene expression were significantly upregulated in the grafted combinations under frost stress conditions. Among the tested rootstocks, ‘Kober 5BB’ markedly improved the spring frost resistance of both cultivars. CH/5BB exhibited the highest activities of POD and APX activity and the greatest induction of VvCBF genes, along with the lowest relative electrical conductivity and H₂O₂ content. These results highlight the critical role of rootstocks in improving scion spring frost resistance and provide important guidance for selecting suitable rootstocks to mitigate the impact of late frosts. Full article

MicroRNAs (miRNAs) act as pivotal post-transcriptional regulators of gene expression in plant stress responses. However, the transcriptional regulation mechanisms governing miRNA genes themselves remain insufficiently characterized. This study focuses on Eca-miR482f, a previously identified cold-responsive miRNA from Eucalyptus camaldulensis that targets EcaSIZ1—a key component of the ICE1–CBFs–CORs cold signaling pathway. We first investigated the expression pattern of Eca-miR482f and found it exhibited root-preferential accumulation in E. camaldulensis. Under cold stress, it displayed divergent organ-specific responses: strong induction in roots and suppression in aerial tissues. To elucidate its transcriptional regulation, we cloned a 1938 bp promoter sequence upstream of the Eca-miR482f precursor. Bioinformatics analysis revealed that this promoter was highly conserved within the Eucalyptus genus and enriched with multiple cis-acting elements associated with stress responses—including a low-temperature-responsive element (LTR)—as well as hormone signaling, such as abscisic acid (ABA) and methyl jasmonate (MeJA)-responsive motifs. A series of 5′-deletion fragments were generated to delineate the functional regions within the promoter. Through transgenic approaches in both tobacco and Arabidopsis, we demonstrated that this promoter drove strong, root-preferential expression. Furthermore, it exhibited significant inducibility under cold and MeJA treatments. Systematic truncation analysis delineated specific promoter regions essential for maintaining this organ specificity and stress responsiveness, thus identifying potential functional modules. Briefly, our findings provide crucial insights into the transcriptional regulation of Eca-miR482f and uncover a valuable genetic tool for future biotechnological engineering of stress-tolerant woody plants via precise spatiotemporal modulation of gene expression. Full article