Search Results (139)

Soil salinity is a major abiotic stress limiting rice growth and grain productivity worldwide. Basic leucine zipper (bZIP) transcription factors serve as central regulators of plant environmental stress responses, yet the biological function and molecular regulatory mechanism of rice OsbZIP60 (LOC_Os07g44950) underlying salinity tolerance remain largely uncharacterized. In this study, we systematically characterized the salt-stress regulatory function of OsbZIP60 in rice. Tissue expression profiling revealed that OsbZIP60 was ubiquitously transcribed across all examined rice tissues, and its encoded protein predominantly localizes to the cell nucleus. Transcript abundance of OsbZIP60 was significantly induced by salt, the osmotic phase, abscisic acid (ABA), and oxidative stress signals. Phenotypic assays demonstrated that overexpression of OsbZIP60 substantially enhanced rice salt tolerance, whereas the bzip60 knockout mutant exhibited aggravated salt hypersensitivity. Physiological quantification revealed that OsbZIP60 promoted the accumulation of osmoprotectants, alleviated salt-triggered oxidative damage, and elevated the activities of core antioxidant enzymes under saline conditions. Moreover, OsbZIP60 maintained intracellular Na⁺/K⁺ homeostasis and positively modulated the transcript levels of a series of salt-responsive downstream genes. Collectively, our results demonstrate that OsbZIP60 acts as a positive regulatory hub that coordinates osmotic adjustment, antioxidant defense, and ion balance to confer salt tolerance in rice, providing a promising genetic target for molecular breeding of salt-tolerant rice varieties. Full article

Melon (Cucumis melo L.) is a globally significant horticultural crop whose fruit quality and postharvest shelf life are profoundly influenced by oxidative stress. Abscisic acid (ABA)-responsive element binding factors (ABFs), which represent the Group A subfamily of the basic leucine zipper (bZIP) transcription factor family, serve as pivotal components in the ABA signaling pathway. These factors play essential roles in regulating plant responses to abiotic stress as well as fruit development and maturation processes. In this study, a total of nine CmABF gene family members (CmABF1–CmABF9) were successfully identified within the melon genome using genome-wide identification techniques. Bioinformatic analysis indicated that all CmABF proteins contain a conserved bZIP domain. Physicochemical property analysis revealed that most of these proteins are unstable hydrophilic proteins and all are localized to the cell nucleus. Phylogenetic analysis categorized the CmABF family into three distinct evolutionary branches (Groups A, B, and C), exhibiting high conservation with homologous genes in Arabidopsis thaliana, Solanum tuberosum, and other species. Promoter analysis demonstrated that CmABF genes are rich in hormone-responsive elements (such as abscisic acid-responsive element (ABRE) and gibberellin-responsive element (GARE)) and stress-responsive elements (such as MYB binding sites (MBS) and anaerobic-response element (ARE)). To investigate their responses to oxidative stress and ABA signaling, we analyzed the expression patterns of these genes in melon fruit at 0, 7, 14, 21, 28, and 35 days of postharvest storage under ozone (O₃, an oxidative stressor), exogenous abscisic acid (ABA), and the ABA synthesis inhibitor nordihydroguaiaretic acid (NDGA) using RNA-seq and qRT-PCR. The results showed that ozone treatment significantly induced the up-regulation of CmABF9 while inhibiting the early expression of CmABF2 and CmABF4. ABA treatment generally promoted the transcription of family members during the late stages of storage (35 d). NDGA treatment suppressed the expression of CmABF2 and CmABF4 during the early storage stage (7 d), while markedly increasing their expression levels at later storage stages (28 d and 35 d), suggesting a compensatory feedback response under endogenous ABA deficiency. Furthermore, protein–protein interaction predictions indicated potential close interactions between CmABF proteins and SnRK2 protein kinases. This study provides a theoretical basis for elucidating the molecular mechanisms of the CmABF family in regulating postharvest oxidative stress in melon and provides candidate gene resources for molecular breeding aimed at enhancing resistance and extending the shelf life of melon fruit. Full article

Basic leucine zipper (bZIP) transcription factors regulate plant development and stress responses, but their genus-wide diversity in Populus remains unclear. We analyzed 19 Populus genomes and retained 1764 bZIP proteins, including 21 independent new loci and four annotation corrections. Of these, 1762 were assigned to 79 orthologous gene groups (OGGs), comprising 43 core, 20 soft-core, 15 shell and one cloud OGG, of which 59 showed copy-number variation. Phylogenetic analysis assigned 74 representative pangenes to 13 subfamilies, with five remaining unclassified and motif patterns differing among subfamilies. Whole-genome duplication (WGD)/segmental duplication accounted for 81.0% of OGG-assigned proteins and contributed predominantly to the conserved component. Although 72.2% of bZIP proteins overlapped a transposable element within the gene body or 2-kb flanks, this proportion was modestly lower than in matched non-bZIP genes, and copy-number-variable OGGs showed no greater TE coverage than invariant OGGs. Among retained homologous comparisons, 97.6% had Ka/Ks ≤ 1, supporting predominant purifying selection. Across the heterogeneous public salt-stress RNA-seq datasets analyzed, no OGG showed a significant, directionally concordant response in at least two Populus taxa. These results reveal a conserved bZIP framework shaped mainly by ancient duplication alongside variable genomic contexts and transcriptional responses. Full article

Redox regulation plays an important role in plant stress responses. Our previous study revealed that rice GLUTATHIONE PEROXIDASE 1 (GPX1) acts as a redox sensor and transducer and promotes osmotic stress tolerance by transfer of cytosolic oxidative signals to transcription factor BASIC LEUCINE ZIPPER 68 (bZIP68). However, the mechanisms governing GPX1 activity and nuclear localization remain unclear. Here, we show that osmotic stress increases GPX1 acetylation. Peroxidase activity and subcellular localization assay indicated that the effects of acetylation on GPX1 function are site-specific, as the acetylation of K94 and K121 enhances GPX1 enzymatic activity, whereas the C-terminal K159/K162/K163 cluster is required for its nuclear translocation. Transgenic complementation and physiological assays confirmed that substitution of K159/K162/K163 sites into arginine abolished GPX1-mediated osmotic stress tolerance and the activation of bZIP68 target genes. Furthermore, we discovered that HISTONE DEACETYLASE 15 (HDA15) interacts with and deacetylates GPX1. HDA15-mediated deacetylation reduced enzymatic activity, nuclear translocation and subsequently the interaction with bZIP68 of GPX1. Accordingly, HDA15-overexpressing rice showed greater membrane damage, weaker induction of bZIP68-regulated genes and increased sensitivity to osmotic stress. These results identify HDA15-mediated GPX1 deacetylation as a negative regulatory mechanism that connects redox enzyme activity, protein localization and stress-responsive transcription in rice. Full article

Strawberry is a globally important yet stress-sensitive crop, increasingly threatened by combined abiotic and biotic stresses. Unlike single stresses, combined stresses elicit unique, non-additive responses through complex signaling and gene regulatory networks. This review synthesizes current knowledge on the molecular mechanisms underlying strawberry responses to combined stresses, focusing on signal perception and transduction as well as gene regulation. We examine how combined stresses are perceived by membrane-localized sensors and calcium channels, and how these signals are transduced through MAPK (mitogen-activated protein kinase) cascades, CDPKs (calcium-dependent protein kinases), and hormonal crosstalk involving ABA (abscisic acid), JA (jasmonic acid), and ethylene. At the gene regulation level, we discuss the roles of key transcription factors (WRKY, NAC (NAM, ATAF1, ATAF2 and CUC2), GRAS (GAI-RGA-and-SCR), DREB (Dehydration-Responsive Element-Binding protein), bZIP (basic leucine zipper transcription factor), CAMTA (calmodulin-binding transcription activator), ARF (auxin response factor), and LAV (Leafy Cotyledon2–Abscisic Acid Insensitive3–Val)), transcriptional cascades, epigenetic regulation via DNA methylation, and post-transcriptional (miRNAs such as Fan-miR73) and post-translational (ubiquitination and phosphorylation) control mechanisms. The review also evaluates emerging mitigation strategies informed by these molecular insights, including genomic selection, and explores future directions such as CRISPR (clustered regularly interspaced short palindromic repeats)-based genome editing and multi-omics integration. We conclude that understanding the integrated signaling and gene regulatory networks is essential for developing climate-resilient strawberry cultivars capable of withstanding increasingly complex stress combinations. Full article

Astragalus membranaceus is an important medicinal plant with considerable pharmacological and economic value; however, its growth and productivity are frequently threatened by drought stress. Basic leucine zipper (bZIP) transcription factors play crucial roles in plant growth, development, and abiotic stress responses, yet a comprehensive investigation of the bZIP gene family in A. membranaceus remains unavailable. In this study, 74 bZIP genes (AmbZIPs) were identified in the A. membranaceus genome and classified into 12 subfamilies based on phylogenetic relationships with Arabidopsis thaliana. Analyses of gene structure, conserved motifs, chromosomal distribution, and duplication events revealed high conservation within subfamilies and indicated that segmental duplication was the major driver of AmbZIP family expansion. Codon usage analysis showed that AmbZIP genes exhibited relatively weak codon usage bias, with codon preference predominantly shaped by natural selection rather than mutation pressure. A total of 23 optimal codons were identified, of which 91.3% were A/T-ending codons. Codon adaptability analysis further demonstrated that tobacco possessed the highest codon compatibility among five tested hosts, whereas Escherichia coli exhibited the lowest adaptability, suggesting that plant expression systems may be more suitable for functional studies of AmbZIP genes. Promoter analysis identified numerous cis-acting elements associated with phytohormone signaling and abiotic stress responses, particularly those related to abscisic acid, methyl jasmonate, salicylic acid, and drought responsiveness. Transcriptome analysis and quantitative real-time polymerase chain reaction (qRT-PCR) validation revealed that several AmbZIP genes were significantly induced under drought stress. Among them, AmbZIP46 displayed strong drought-responsive expression, transcriptional activation activity, and exclusive nuclear localization. These findings provide the first comprehensive characterization of the bZIP gene family in A. membranaceus and establish a valuable foundation for elucidating drought-tolerance mechanisms and facilitating molecular breeding in this medicinal plant. Full article

Basic leucine zipper (bZIP) transcription factors are widely involved in plant development and stress responses. Cymbidium goeringii (Rchb.f.) Rchb.f. is a globally important ornamental orchid whose growth is frequently constrained by extreme heat, yet genome-wide information on its bZIP genes and their responses to heat treatment remains limited. In this study, 67 CgbZIP genes were identified from the C. goeringii genome; 63 were assigned to 10 subfamilies based on phylogenetic relationships, while four remained unclassified. RT-qPCR analysis showed that selected CgbZIP genes displayed different transcript-level responses under heat treatment. CgbZIP4 showed increased transcript abundance under heat treatment, whereas CgbZIP49, CgbZIP50, CgbZIP53, and CgbZIP2 showed reduced transcript abundance. CgbZIP25 displayed a fluctuating expression pattern during the 24 h treatment. Yeast two-hybrid assays supported a possible physical interaction between CgbZIP4 and CgbZIP25 in yeast. These results provide candidate CgbZIP genes for further functional studies of heat-stress responses in C. goeringii. Full article

Background/Objectives: Myelodysplastic syndromes (MDS) carry a highly variable prognosis, stratified by the Revised International Prognostic Scoring System (IPSS-R) and the Molecular IPSS (IPSS-M). CEBPA mutations define a favorable-risk subgroup in acute myeloid leukemia (AML), yet their prognostic significance in MDS has not been characterized. Methods: We analyzed 2442 patients from the International Working Group (IWG) 2022 multi-center MDS registry after pre-specified exclusions. Overall survival (OS) and leukemia-free survival (LFS) were compared between CEBPA-mutated (n = 66; 2.7%) and wild-type patients using Kaplan–Meier estimation and Cox proportional hazards regression, adjusting for age, sex, and IPSS-R score; pre-specified subgroup, sensitivity, competing-risk, and mutation subtype analyses were performed. Results:CEBPA-mutated patients had markedly inferior OS (median 17.2 versus 42.2 months; HR 2.05, 95% CI 1.50–2.79; p < 0.001). After IPSS-R adjustment, the hazard ratio remained adverse (HR 1.39, 95% CI 1.00–1.94; p = 0.053), with uniform directionality across all 13 evaluable subgroups and no significant interaction. Co-mutation adjustment for ASXL1 and STAG2 further attenuated the hazard ratio to HR 1.11 (95% CI 0.79–1.57; p = 0.54), suggesting part of the observed signal reflects co-mutation burden rather than an independent CEBPA effect. Competing-risk analysis suggested that the excess mortality is mediated through AML transformation (CEBPA-mutated versus wild-type subdistribution hazard ratio of 1.89, 95% CI 1.20–2.99; p = 0.006) rather than non-transformative MDS mortality (cause-specific HR 0.97; p = 0.890). Truncating mutations drove the adverse signal (HR 2.21; p = 0.023), while basic leucine zipper (bZIP) domain mutations showed no significant effect (HR 1.25; p = 0.470). Conclusions:CEBPA mutations identify a rare MDS subgroup with markedly inferior survival, driven by truncating loss-of-function mutations and associated with leukemic transformation; the AML-derived bZIP-favorable paradigm does not translate to MDS, and CEBPA mutation status merits a prospective study to assess clinical utility for risk stratification. Full article

Basic-region leucine zipper (bZIP) transcription factors are crucial for plant stress responses, but their characterization in the wild species Juglans mandshurica remains limited. Here, we identified 80 bZIP genes in the J. mandshurica genome and classified them into 13 subgroups, with notable enrichment in subgroups S, A, D, and I. All subgroup D members contain both bZIP and DELAY OF GERMINATION 1 (DOG1) domains, forming characteristic dual-module fusion proteins. Evolutionary analysis detected three orthologous gene pairs under positive selection since divergence from Juglans regia. Promoter cis-elements, especially MYB and MYC motifs, are abundant in JmbZIP genes. Protein–protein interaction networks suggest potential functional specialization and coordination among JmbZIP members. Expression profiling revealed distinct patterns across subgroups, with S, A, and D showing high activity across various physiological processes and light stress responses. qRT-PCR validated the dynamic expression of six ABA pathway marker genes, the ABRE-rich JmbZIP41 and JmbZIP42 genes, together with the highly expressed JmbZIP12 gene under salt and drought stress. Our genome-wide analysis enabled the functional screening of bZIP members across subgroups. The key genes identified in this study provide valuable genetic resources for stress-resistance breeding in forest trees, with JmABI5 (JmbZIP40) and JmbZIP42 serving as prime candidates for enhancing tree stress tolerance. Full article

D-box binding protein (DBP) is a high-amplitude proline- and acidic amino acid-rich basic leucine zipper (PAR bZIP) transcription factor that functions as a key circadian output regulator downstream of the core molecular clock. Although DBP is widely recognized as a clock-controlled gene, its broader role in converting circadian timing into tissue-specific physiological programs remains incompletely integrated. In this review, we synthesize current evidence supporting DBP as a context-dependent D-box-centered regulatory node. We first summarize the upstream mechanisms that establish rhythmic Dbp expression, including CLOCK–BMAL1-dependent transcription, promoter-level amplification, signaling-dependent modulation, and post-translational control of DBP stability. We then discuss how DBP, together with related PAR bZIP activators and the opposing repressor E4 promoter-binding protein 4/nuclear factor interleukin 3 regulated (E4BP4/NFIL3), regulates D-box-mediated transcriptional output. Finally, we examine tissue-selective DBP functions in hepatic metabolism, pancreatic β-cell secretory competence, neural and behavioral regulation, reproductive neuroendocrine timing, and T helper 9 (Th9)-associated antitumor immunity. Across these systems, DBP does not act as a universal circadian effector; rather, its function depends on chromatin accessibility, cofactor availability, competing transcription factors, and local signaling context. We also highlight the current limits of human translational evidence and propose that DBP-centered signatures may be useful for interpreting circadian output failure in disease. Overall, DBP provides a mechanistically informative framework for understanding how circadian time is transformed into organ-specific physiological function and pathological vulnerability. Full article

Gene duplication is a primary evolutionary driver of gene family expansion and functional diversification in plants, yet how different duplication processes reshape the evolutionary architecture of transcription factor repertoires remains poorly resolved in lineage-specific genomic contexts. Here, we performed a comprehensive evolutionary and transcriptomic analysis of the basic leucine zipper (bZIP) family across 17 representative species, with a focus on Pooideae. We identified 1878 bZIP genes and found that, although copy numbers were relatively conserved in most diploid grasses, polyploid Triticeae showed substantial expansion. Genome-wide and Ks analyses indicated that bZIP genes were preferentially retained after whole-genome/segmental duplication, with many copies tracing back to the ancient grass-specific ρ-WGD event, the most recent shared polyploidization event in Poaceae. Phylogenetic analyses and orthology inference further resolved four evolutionary models linking ancient duplication with lineage-specific retention and expansion. Transcriptome analyses revealed structured expression divergence across developmental and stress-related contexts, and wheat homoeologous triads exhibited widespread subgenome expression bias that was dynamically reconfigured under stress and hormone treatments. Differences in transposable element landscapes among duplication models and subgenomes further suggest a role for local genomic context in regulatory divergence. Together, these findings establish a unified framework linking ancient duplication, selective retention, and transcriptional diversification of the bZIP family in Pooideae. Full article

Basic leucine zipper (bZIP) transcription factors are widely involved in plant growth, development, environmental adaptation, and secondary metabolism. However, the bZIP gene family in Taxus yunnanensis has not been systematically characterized, and its potential involvement in shading-responsive regulation of paclitaxel biosynthesis remains unclear. In this study, a genome-wide analysis was performed to identify and characterize the bZIP family in T. yunnanensis. Phylogenetic analysis, conserved motif and domain identification, promoter cis-element analysis, chromosomal localization, and expression profiling were conducted to investigate their structural features and regulatory potential. A total of 18 TyubZIP genes were identified and classified into 10 subfamilies. These genes exhibited variation in physicochemical properties but showed conserved structural features and nuclear localization. Promoter analysis revealed abundant light-responsive, hormone-related, and stress-related cis-elements. Expression profiling indicated tissue-specific expression patterns and diverse responses to shading treatment. WGCNA further identified candidate TyubZIP genes potentially associated with paclitaxel biosynthesis. Among them, TyuHY5 was selected for functional analysis. Subcellular localization and transcriptional assays demonstrated that TyuHY5 can bind to the promoter of TyuDBTNBT and positively regulate its activity. These findings provide the first genome-wide characterization of the bZIP family in T. yunnanensis and identify TyuHY5 as a shading-responsive candidate regulator of paclitaxel biosynthesis, providing insights that may inform the genetic improvement and cultivation strategies of Taxus for enhanced paclitaxel production. Full article

Low-temperature stress significantly limits plant growth, development, and productivity, posing a major environmental constraint. The potato (Solanum tuberosum L.) is particularly vulnerable to low temperatures, underscoring the crucial need to enhance cold tolerance in potato breeding efforts for sustainable production. Basic leucine zipper (bZIP) transcription factors serve as central regulators of plant developmental processes and stress responses; however, their functional role in cold tolerance in tetraploid potato remains poorly understood. Here, we report a systematic characterization of the bZIP gene family in tetraploid potato and provide preliminary evidence that StbZIP104 enhances plant cold tolerance. A total of 191 StbZIP genes were identified and classified into 11 subfamilies, exhibiting uneven chromosomal distribution and expansion primarily driven by whole-genome and segmental duplication. Promoter cis-element analysis, together with GO and KEGG enrichment analyses, indicated that StbZIP genes are broadly associated with hormone signaling, stress responses, signal transduction, and environmental adaptation. Expression profiling under low-temperature treatment revealed eight cold-inducible StbZIP genes (log₂FC ≥ 1 and FDR < 0.05), among which StbZIP104 was strongly induced (log₂FC ≥ 2) and showed 5.36-fold higher expression in highly cold-resistant cultivars than in cold-sensitive cultivars. Subcellular localization confirmed that StbZIP104 is a nuclear-localized protein. Functional validation confirmed that overexpressing StbZIP104 notably improved cold tolerance in transgenic Samsun NN tobacco (Nicotiana tabacum cv. Samsun NN). This was supported by heightened superoxide dismutase and peroxidase activities, increased levels of soluble protein and soluble sugars, and decreased malondialdehyde content compared to the wild type under cold stress. This study establishes a basis for the functional characterization of the bZIP gene family in tetraploid potato and serves as a theoretical reference for understanding the mechanisms that govern cold tolerance in this species. Full article

The functions of the putative bZIP (basic leucine zipper) transcription factors ZipV (Afu3g032301) and ZipZ (Afu2g14350) were investigated using wild-type, gene-deficient, and complemented strains of Aspergillus fumigatus. Deletion of zipV increased oxidative stress sensitivity and reduced in vivo virulence in a Galleria mellonella model, whereas complementation restored the wild-type phenotype. In contrast, deletion of zipZ resulted in no detectable phenotypic changes, even though transcription of both genes was modulated by oxidative stress. Phenotypic characterization of conidia, transcriptomic analyses of growing cultures and reverse-transcription quantitative real-time PCR of conidia-producing cultures suggested that ZipV regulates the development of certain conidial traits. The conidia of the ∆zipV mutant showed reduced heat stress tolerance, decreased catalase activity and delayed germination in comparison to the wild-type or the complemented strain. In the ∆zipV mutant, the transcription of catA encoding conidial catalase was impaired. This defect explains the reduced catalase activity and the oxidative stress sensitivity of the mutant and may contribute to its reduced virulence. The increased transcriptional activity of the alternative oxidase gene aoxA observed in the absence of ZipV suggests a compensatory response aimed at mitigating oxidative stress. Full article

Osmotic stress limits rice productivity, yet the crosstalk between hydrogen sulfide signaling and redox regulation remains incompletely understood. We previously showed that redox-dependent oligomerization of the basic (region) leucine zippers transcription factor bZIP68 at Cys245 confers osmotic tolerance. However, the role of an adjacent cysteine, Cys171, was undefined. Here, we demonstrate that osmotic stress induces persulfidation of bZIP68 specifically at Cys171. This modification facilitates Cys245-mediated oxidation-dependent oligomerization, thereby enhancing bZIP68 transcriptional activity toward COLD-REGULATED413-THYLAKOID MEMBRANE1 (COR413-TM1). Transgenic complementation and physiological assays confirmed that Cys171 persulfidation is essential for full bZIP68 function in osmotic adaptation. Transcriptomic analysis further revealed that Cys171 is required for bZIP68-driven transcriptional reprogramming under stress. Our findings establish a hierarchical redox cascade wherein persulfidation primes bZIP68 for oxidative activation, highlighting a regulatory crosstalk between distinct post-translational modifications. These mechanistic insights expand our understanding of H₂S signaling and identify the bZIP68 cysteine network as a potential target for improving crop stress resilience. Full article