bZIP Transcription Factor Research Articles

Translation elongation defects activate the Caenorhabditis elegans ZIP-2 bZIP transcription factor-mediated toxin defense.

The Caenorhabditis elegans bZIP transcription factor ZIP-2 is activated by toxins or mutations that inhibit translational elongation. The zip-2 DNA-binding protein is encoded in a downstream main open reading frame (mORF), but under normal translation elongation conditions only an upstream overlapping oORF -1 frameshifted from mORF is translated. Mutations or toxins that slow translational elongation, but not inhibitors of translational initiation or termination, activate ZIP-2. An mORF initiation codon mutation does not disrupt the normal zip-2 response to translational elongation defects, suggesting that zip-2 activation does not depend on this ATG. An mORF early termination mutant can be activated by strong translation elongation inhibition, suggesting that translation initiated upstream on oORF +1 frameshifts when elongation is inhibited to the mORF reading frame downstream of the stop codon to activate a fused oORF/mORF ZIP-2 transcription factor. The protein and DNA sequences of zip-2 oORF and mORF are conserved across the Caenorhabditis, suggesting selection for particular codons sensitive to translational elongation defects. Mutations that disrupt the oORF initiation codon constitutively activate zip-2, but not if the mORF initiation codon is also mutant, showing that zip-2 oORF competes with mORF for translational initiation. oORF initiation codon mutation-activated zip-2 slows C. elegans growth, and this slow growth is suppressed by a zip-2 null mutation. A zip-2 null mutant also strongly suppresses the growth arrest caused by translational elongation inhibitors. Thus, ZIP-2 is both a sensor of translational elongation attack, and a defense regulatory output via its activation of response genes.

OsbZIP23 delays flowering by repressing OsMADS14 expression in rice

Flowering time is a fundamental factor determining the global distribution and final yield of rice (Oryza sativa L.). The initiation of the floral transition process signifies the beginning of the reproductive phase. The florigens Heading Date 3a (Hd3a) and Rice Flowering Locus T 1 (RFT1) combine with GF14 proteins and OsFD-like basic leucine zipper (bZIP) transcription factors to form florigen activation/repressor complexes (FACs/FRCs) that regulate the transition to flowering. We herein report that a bZIP transcription factor (OsbZIP23) functions as a flowering repressor. Transgenic plants overexpressing OsbZIP23 exhibited delayed flowering, which was in contrast to the slightly early flowering of the osbzip23 mutants, under natural short-day and long-day conditions. Molecular and biochemical analyses indicated that OsbZIP23 can bind to the 5′ untranslated region of OsMADS14 and suppress expression. Moreover, it delays the floral transition probably by interacting with OsFTL1/Hd3a/RFT1 and 14-3-3 proteins to form FRCs. Our findings have further elucidated the molecular mechanisms regulating the flowering time in rice.

Carbon dioxide suppresses filamentous growth in the human fungal pathogen Candida tropicalis.

A striking characteristic of the human fungal pathogen Candida albicans is its ability to switch between budding yeast morphology and the filamentous form, facilitating its adaptation to changing host environments. The filamentous growth of C. albicans is mediated by various environmental factors, such as carbon dioxide (CO2), N-acetylglucosamine (GlcNAc), serum, and high temperature. Despite extensive studies in C. albicans, the regulatory mechanism of filamentation in Candida tropicalis, a fungal species that is closely related to C. albicans, has not been well characterized. In this study, we reveal opposite roles of CO2 in regulating filamentation among Candida species: CO2 promotes filamentous growth in C. albicans and Candida dubliniensis, whereas it inhibits filamentation in C. tropicalis. Despite the critical role of the canonical cAMP pathway in filamentation, it is dispensable in CO2-regulated filamentation in C. tropicalis. A CO2-specific signaling is involved in the regulation of filamentous growth in C. tropicalis. Additionally, we identify two key elements involved in CO2 sensing in C. tropicalis: a single carbonic anhydrase (CA) Nce103 and the bZIP transcription factor Rca1. Both Nce103 and Rca1 are important for cellular growth in ambient air and negatively regulate filamentous development in response to CO2 in C. tropicalis. These findings reveal a distinct mechanism underlying CO2-regulated filamentation in C. tropicalis, contributing to a deeper understanding of its unique survival strategies in diverse environmental niches and providing new insights into the adaptive evolution of CO2 sensing mechanisms among various fungal pathogens.

Identification of Leaf Stripe Resistance Genes in Hulless Barley Landrace Teliteqingke from Qinghai-Tibet Plateau

Leaf stripe disease, caused by Pyrenophora graminea, is a seed-borne fungal disease that significantly impacts hulless barley (Hordeum vulgare var. nudum) production on the Qinghai-Tibet Plateau. This study aimed to identify genetic factors conferring resistance to the leaf stripe by analyzing an F3 population derived from a cross between the resistant landrace Teliteqingke and the susceptible landrace Dulihuang. Genetic analysis revealed that resistance in Teliteqingke was governed by two dominant genes. Using bulked segregant analysis combined with an SNP array (BSA-SNP) and RNA-seq, we identified two candidate regions on chromosomes 3H and 7H. Further analysis focused on chromosome 3H, which revealed a candidate genomic region containing seven potential disease-resistance genes. Among these, RT-qPCR experiments demonstrated significant expression induction of HORVU.MOREX.r3.3HG0232110.1 (encoding a RING/U-box superfamily protein) and HORVU.MOREX.r3.3HG0232410.1 (encoding a bZIP transcription factor) showed significant expression induction following inoculation with P. graminea. These genes are strong candidates for the resistance mechanism against leaf stripes in Teliteqingke. These results provide a foundation for functional validation of these genes and offer valuable insights for breeding disease-resistant hulless barley.

Dancing Molecules: Group A bZIPs and PEBPs at the Heart of Plant Development and Stress Responses.

Group A basic leucine zipper (bZIP) transcription factors play critical roles in abscisic acid (ABA) signaling and plant development. In Arabidopsis thaliana, these factors are defined by a highly conserved core bZIP domain, and four conserved domains throughout their length: three at the N-terminus (C1 to C3) and a phosphorylatable C-terminal SAP motif located at the C4 domain. Initially, members such as ABI5 and ABFs were studied for their roles in ABA signaling during seed germination or stress responses. Later, a sub-clade of group A bZIPs, including FD, was found to play important roles in floral induction by interacting with the florigen FLOWERING LOCUS T (FT) at the shoot apical meristem. Recent research has expanded our understanding of these transcription factors by identifying intriguing parallels between those involved in ABA signaling and those promoting floral induction, and revealing dynamic interactions with FT and other phosphatidylethanolamine-binding proteins (PEBP) such as TERMINAL FLOWER 1. Studies in crop plants and non-model species demonstrate broader roles, functions, and molecular targets of group A bZIPs. This review highlights common features of group A bZIPs and their post-translational regulation in enabling the activation of gene regulatory networks with important functions in plant development and stress responses.

Regulatory networks of bZIPs in drought, salt and cold stress response and signaling.

Abiotic stresses adversely impact plants survival and growth, which in turn affect plants especially crop yields worldwide. To cope with these stresses, plant responses depend on the activation of molecular networks cascades, including stress perception, signal transduction, and the expression of specific stress-related genes. Plant bZIP (basic leucine zipper) transcription factors are important regulators that respond to diverse abiotic stresses.By binding to specific cis-elements, bZIPs can control the transcription of target genes, giving plants stress resistance. This review describes the structural characteristics of bZIPs and summarizes recent progress in analyzing the molecular mechanisms regulating plant responses to salinity, drought, and cold in different plant species. The main goal is to deepen the understanding of bZIPs and explore their value in genetic improvement of plants.

Multiple regulators constrain the abundance of C. elegans DLK-1 in ciliated sensory neurons.

The conserved MAP3K DLKs are widely known for their functions in synapse formation, axonal regeneration and degeneration, and neuronal survival, notably under traumatic injury and chronic disease conditions. In contrast, their roles in other neuronal compartments are much less explored. Through an unbiased forward genetic screening in C. elegans for altered patterns of GFP-tagged DLK-1 expressed from the endogenous locus, we have recently uncovered a mechanism by which the abundance of DLK-1 is tightly regulated by intraflagellar transport in ciliated sensory neurons. Here, we report additional mutants identified from the genetic screen. Most mutants exhibit increased accumulation of GFP::DLK-1 in sensory endings, and the levels of misaccumulated GFP::DLK-1 are exacerbated by loss of function in cebp-1, the b-Zip transcription factor acting downstream of DLK-1. We identify several new mutations in genes encoding proteins functioning in intraflagellar transport and cilia assembly, in components of BBSome, MAPK-15 and DYF-5 kinases. We report a novel mutation in the chaperone HSP90 that causes misaccumulation of GFP::DLK-1 and up-regulation of CEBP-1 selectively in ciliated sensory neurons. We also find that the guanylate cyclase ODR-1 constrains GFP::DLK-1 abundance throughout cilia and dendrites of AWC neurons. Moreover, in odr-1 mutants, AWC cilia display distorted morphology, which is ameliorated by loss of function in dlk-1 or cebp-1. These data expand the landscape of DLK-1 signaling in ciliated sensory neurons and underscore a high degree of cell- and neurite- specific regulation.

Genome-Wide Analysis of bZIP Transcription Factors and Expression Patterns in Response to Salt and Drought Stress in Vaccinium corymbosum.

The basic leucine zipper (bZIP) transcription factors play essential roles in multiple stress responses and have been identified and functionally characterized in many plant species. However, the bZIP family members in blueberry are unclear. In this study, we identified 102 VcbZIP genes in Vaccinium corymbosum. VcbZIPs were divided into 10 groups based on phylogenetic analysis, and each group shared similar motifs, domains, and gene structures. Predictions of cis-regulatory elements in the upstream sequences of VcbZIP genes indicated that VcbZIP proteins are likely involved in phytohormone signaling pathways and abiotic stress responses. Analyses of RNA deep sequencing data showed that 18, 13, and 7 VcbZIP genes were differentially expressed in response to salt, drought, and ABA stress, respectively, for the blueberry cultivar Northland. Ten VcbZIP genes responded to both salt and drought stress, indicating that salt and drought have unique and overlapping signals. Of these genes, VcbZIP1-3 are responsive to salt, drought, and abscisic acid treatments, and their encoded proteins may integrate salt, drought, and ABA signaling. Furthermore, VcbZIP1-3 from group A and VcbZIP83-84 and VcbZIP75 from group S exhibited high or low expression under salt or drought stress and might be important regulators for improving drought or salt tolerance. Pearson correlation analyses revealed that VcbZIP transcription factors may regulate stress-responsive genes to improve drought or salt tolerance in a functionally redundant manner. Our study provides a useful reference for functional analyses of VcbZIP genes and for improving salt and drought stress tolerance in blueberry.

Deletion of bZIP Transcription Factor PratfA Reveals Specialized Metabolites Potentially Regulating Stress Response in Penicillium raistrickii.

Fungal secondary metabolism (SM) is highly correlated with physiological processes that are typically regulated by pleiotropic regulators. In this study, we purposefully altered PratfA, a crucial regulator associated with oxidative stress in Penicillium raistrickii CGMCC 3.1066. After the knockout of PratfA, a novel polyketide (PK) raistrilide A (1) and the known nonribosomal peptide (NRP) tunicoidine (2) subsequently disappeared. Notably, compound 1 is a rare octaketone derivative and contains two unsubstituted cis-double bonds, demonstrating its unique biosynthetic mechanism. The knockout of PratfA resulted in the disappearance of 1-2 and greatly increased the susceptibility of ΔPratfA mutant strain to oxidative stress, rendering it nearly impossible to survive in such environments. At present, the OE⸬PratfA strain showed no phenotypic or oxidative stress sensitivity differences compared to the wild-type strain. Our findings highlight that the oxidative-stress-related transcription factor (TF) PratfA influences SM pathways in P. raistrickii. The manipulation of regulatory factors can guide the discovery of novel natural products (NPs).

Nitrogen availability modulates carotene biosynthesis, chromoplast biogenesis, and cell wall composition in carrot callus.

Carrot callus grown on a medium with increased nitrogen have reduced carotenoid accumulation, changed gene expression, high amount of vesicular plastids and altered cell wall composition. Carotenoid biosynthesis is vital for plant development and quality, yet its regulation under varying nutrient conditions remains unclear. To explore the effects of nitrogen (N) availability, we used carrot (Daucus carota L.) model callus cultures in vitro as a controlled system for studying nutrient-regulated metabolic processes. Two mineral media differing in N content and NO₃⁻/NH₄⁺ ratios were used. Comprehensive analyses, HPLC, transmission electron microscopy, immunochemistry, and RNA sequencing, revealed notable cellular and molecular responses to N treatments. The results demonstrated that N supplementation reduced carotenoid content by 50%, particularly β-carotene and α-carotene. The composition of chromoplast types shifted, with vesicular chromoplasts dominating (55%), followed by a globular type (23%), while in the control callus, globular and crystalline types predominated (57% and 33%, respectively). Immunohistochemistry showed increased presence of high-esterified pectins and arabinogalactan proteins in N-treated cells. Transcriptomic analysis identified 1704 differentially expressed genes (DEGs), including only two in the carotenoid biosynthesis pathway: phytoene synthase 2 (PSY2) and zeaxanthin epoxidase (ZEP). PSY2, which encodes the carotenoid rate-limiting enzyme, showed expression levels that corresponded with reduced carotene content. Other DEGs included 15 involved in nitrogen transport, 1 in nitrogen assimilation, 40 in cell wall biosynthesis and modification, and 9 in phenylpropanoid/flavonoid pathways. N-treated callus exhibited altered expression of MADS-box, NLP, bZIP, and ethylene-responsive transcription factors. These findings reveal how nitrogen availability disrupts carotenoid biosynthesis and triggers extensive chromoplast and cell wall remodeling, providing a cellular framework for understanding nutrient-regulated metabolic shifts.

Identification of the Granule-Bound Starch Synthase (GBSS) Genes Involved in Amylose Biosynthesis in Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn.).

Tartary buckwheat is a nutrient-rich pseudo-cereal whose starch contents, including amylose and amylopectin contents, and their properties hold significant importance for enhancing yield and quality. The granule-bound starch synthase (GBSS) is a key enzyme responsible for the synthesis of amylose, directly determining the amylose content and amylose-to-amylopectin ratio in crops. Although one has already been cloned, the GBSS genes at the genome-wide level have not yet been fully assessed and thoroughly analyzed in Tartary buckwheat. This study comprehensively analyzed the FtGBSSs in Tartary buckwheat. Based on the genome data of Tartary buckwheat, five FtGBSS genes, namely FtGBSS-1 to FtGBSS-5, were identified on three chromosomes, exhibiting about 1800 bp lengths in their CDSs and numerous exons and introns in gene structures. Amino acid analyses revealed high homology in ten GBSS proteins from Tartary buckwheat, rice, maize, and Arabidopsis thaliana, with a specific starch synthase catalytic domain and ten conserved motifs. The Tartary buckwheat GBSS proteins had a closer relationship with GBSS proteins from monocot based on evolutionary relationship analysis. Expression analyses suggested that the FtGBSS genes showed distinct tissue-specific expression patterns in Tartary buckwheat and rice-Tartary buckwheat. Among them, FtGBSS-1, FtGBSS-2, and FtGBSS-4 were higher expressed in the root, stem, or flower, suggesting that they have a role in the amylose synthesis of these tissues. Notably, FtGBSS-3 and FtGBSS-5 were more highly expressed in seeds than in other tissues, suggesting that they have a pivotal role in amylose synthesis of the seeds of Tartary buckwheat. Furthermore, the cis acting elements in the promoters of FtGBSSs and their binding transcription factors (TFs) were investigated. A protein-protein interaction network was constructed and co-expression was analyzed based on the gene expression patterns of the FtGBSSs, and the identified TFs, belonging to bZIP, ERF, bHLH, and MADS-box TF families, were identified within this network, and their expression patterns were significantly correlated to the expression patterns of two seed-specific FtGBSS genes (FtGBSS-3 and FtGBSS-5). Finally, FtGBSS1-5 was successfully transformed into rice through transgenic manipulation, and the FtGBSS1-5 overexpression lines showed an increase in amylose content accompanied by a reduction in amylopectin and total starch contents compared with WT. Overall, this research not only deepens our understanding of the molecular mechanisms of amylose synthesis in Tartary buckwheat, but also provides scientific insights for enhancing crop amylose content and quality through molecular breeding.

The ecdysone-induced bZIP transcription factor MafB establishes a positive feedback loop to enhance vitellogenesis and reproduction in the Aedes aegypti mosquito

Female mosquitoes require a vertebrate blood meal to activate reproduction, transmitting numerous devastating human diseases. Vitellogenesis is a central event of female reproduction that involves the massive production of vitellogenin (Vg) in the fat body and the maturation of ovaries. This process is controlled by the steroid hormone 20-hydroxyecdysone (20E); however, its molecular regulatory basis remains not completely understood. We found that the expression of Aedes aegypti muscle aponeurosis fibromatosis B (AaMafB), coding for a basic leucine zipper (bZIP) transcription factor, was significantly up-regulated after a blood meal. The 20E-bound ecdysone receptor-ultraspiracle heterodimer directly targeted the ecdysone response element in the promoter of AaMafB, activating its transcription. Coimmunoprecipitation assays illustrated the interaction between AaMafB and Cap "n" collar C (AaCncC), another bZIP transcription factor. RNA interference-mediated depletion of AaMafB or AaCncC led to impaired ovarian growth, decreased expression of AaVg and Halloween genes, and reduced 20E levels. The AaMafB-AaCncC heterodimer directly activated the transcription of AaVg and AaShade by targeting the antioxidant response element in their promoters. Together, our results indicate that AaMafB functions as an early 20E response gene, the product of which heterodimerizes with AaCncC to maintain high 20E levels and facilitates activation of AaVg in mosquitoes after a blood meal.

A Basic Leucine Zipper Transcription Factor, AsbZIP26, Positively Regulates the Synthesis of Alliin in Garlic (Allium sativum L.)

Garlic is a significant medicinal and culinary plant, with its primary bioactive compound being alliin. The bZIP transcription factor is pivotal in plant secondary metabolism and growth, yet its function in garlic remains unexplored. The previously identified key enzyme gene, AsFMO1 in garlic, is known to directly regulate alliin synthesis, however, the specific molecular mechanism is still unknown. In this research, the transcription factor AsbZIP26 was discovered in the leaves of purple-skinned garlic in PiZhou, demonstrating a positive regulatory role in alliin biosynthesis. Transcriptomic data indicated that mechanical damage stress highly induced the expression of the AsbZIP26 gene, a favorable condition for alliin synthesis. Subcellular localization revealed nuclear targeting of AsbZIP26. Employing yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA) analysis, and chromatin immunoprecipitation (ChIP), it was confirmed that AsbZIP26 specifically binds to the G-box region of the AsFMO1 promoter, directly activating its expression and playing a crucial function in garlic biosynthesis. Overexpression of AsbZIP26 in garlic callus tissues resulted in increased alliin levels. Overall, this study discovered a functional transcription factor AsbZIP26 in garlic, which can regulate the synthesis of alliin in garlic, filling the gap in the alliin synthesis pathway and providing new ideas for garlic breeding and selection for improving garlic varieties.

Sakuranetin Prevents Acetaminophen-Induced Liver Injury via Nrf2-Induced Inhibition of Hepatocyte Ferroptosis.

Oxidative stress is an important cause of acetaminophen (APAP)-induced liver injury (AILI). Sakuranetin (Sak) is an antitoxin from the cherry flavonoid plant with good antioxidant effects. However, whether sakuranetine has a protective effect on APAP-induced liver injury is not clear. Mouse and HepG2 cell models of APAP injury were used to investigate the effect of sakuranetin on AILI and its mechanism. Serum transaminase levels, histological changes, inflammatory mediators, oxidative stress, ferroptosis-related markers and Nrf2 signaling pathway proteins were analyzed. Sakuranetin significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as inflammatory factor; increased HepG2 activity and decreased cell death; inhibited ROS production, increased glutathione (GSH) content, expression of Glutathione Peroxidase 4 (GPX4) and Solute Carrier Family 7 Member 11 (SLC7A11), and decreased malondialdehyde and Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) expression in mice and HepG2 cells after APAP treatment. Further analysis showed that sakuranetin induced the activation of the NFE2 Like BZIP Transcription Factor 2 (Nrf2) signaling pathway in liver tissue and HepG2 cells and promoted the nuclear translocation of Nrf2. Moreover, the hepatoprotective effect of sakuranetin and its inhibitory effect on ferroptosis were significantly attenuated by the Nrf2 inhibitor ML385. Sakuranetin alleviates AILI by activating the Nrf2 signaling pathway and inhibiting ferroptosis, and sakuranetin may be a potential therapeutic agent for the treatment of AILI.

Systematic characterization of the bZIP gene family in Colletotrichum siamense and functional analysis of three family members

The basic leucine zipper (bZIP) transcription factors (TFs) play important roles in many physiological processes of plant-pathogenic fungi, especially concerning fungal development, fungicide resistance, and pathogenicity. Colletotrichum siamense is the predominant species causing Colletotrichum leaf disease (CLD) in rubber trees. However, little is known about the bZIP genes in C. siamense. In this study, 25 bZIP genes were systematically identified in the genome of C. siamense, and molecular features were characterized. Evolutionarily, the CsbZIP genes were divided into 11 groups, with the members in the same group sharing similar gene structures and conserved protein motif organizations. Furthermore, protein-protein interaction (PPI) analysis revealed that 15 bZIP proteins had functional partners in common or interacted with other CsbZIP proteins. Additionally, the expression of 23 CsbZIP genes changed in response to the antifungal chemicals melatonin, prochloraz, and thymol, and the genes could be divided into three clusters based on their expression patterns. Finally, gene deletion mutants of CsbZIP01/09/17 were constructed and functional analysis indicated that these genes operated as important regulators of mycelial growth, fungicide resistance, ergosterol biosynthesis, and virulence in C. siamense. This study provided the foundations crucial for further investigation of the functions of CsbZIP TFs in fungicide resistance and virulence.

Somatic mutations and DNA methylation identify a subgroup of poor prognosis within lower-risk myelodysplastic syndromes.

Lower risk (LR) myelodysplastic syndromes (MDS) are heterogeneous hematopoietic stem and progenitor disorders caused by the accumulation of somatic mutations in various genes including epigenetic regulators that may produce convergent DNA methylation patterns driving specific gene expression profiles. The integration of genomic, epigenomic, and transcriptomic profiling has the potential to spotlight distinct LR-MDS categories on the basis of pathophysiological mechanisms. We performed a comprehensive study of somatic mutations and DNA methylation in a large and clinically well-annotated cohort of treatment-naive patients with LR-MDS at diagnosis from the EUMDS registry (ClinicalTrials.gov.NCT00600860). Unsupervised clustering analyses identified six clusters based on genetic profiling that concentrate into four clusters on the basis of genome-wide methylation profiling with significant overlap between the two clustering modes. The four methylation clusters showed distinct clinical and genetic features and distinct methylation landscape. All clusters shared hypermethylated enhancers enriched in binding motifs for ETS and bZIP (C/EBP) transcription factor families, involved in the regulation of myeloid cell differentiation. By contrast, one cluster gathering patients with early leukemic evolution exhibited a specific pattern of hypermethylated promoters and, distinctly from other clusters, the upregulation of AP-1 complex members FOS/FOSL2 together with the absence of hypermethylation of their binding motif at target gene enhancers, which is of relevance for leukemic initiation. Among MDS patients with lower-risk IPSS-M, this cluster displayed a significantly inferior overall survival (p < 0.0001). Our study showed that genetic and DNA methylation features of LR-MDS at early stages may refine risk stratification, therefore offering the frame for a precocious therapeutic intervention.

Specific Transcriptional Regulation Controls Plant Organ-Specific Infection by the Oomycete Pathogen Phytophthora sojae.

The organs of a plant species vary in cell structure, metabolism and defence responses. However, the mechanisms that enable a single pathogen to colonise different plant organs remain unclear. Here we compared the transcriptome of the oomycete pathogen Phytophthora sojae during infection of roots versus leaves of soybeans. We found differences in the transcript levels of hundreds of pathogenicity-related genes, particularly genes encoding carbohydrate-active enzymes, secreted (effector) proteins, oxidoreductase-related proteins and transporters. To identify the key regulator for root-specific infection, we knocked out root-specific transcription factors (TFs) and found the mutants of PsBZPc29, which encodes a member of an oomycete-specific class of basic leucine zipper (bZIP) TFs, displayed reduced virulence on soybean roots but not on leaves. More than 60% of the root-specific genes showed reduced expression in the mutants during root infection. The results suggest that transcriptional regulation underlies the organ-specific infection by P. sojae, and that a bZIP TF plays a key role in root-specific transcriptional regulation.

Regulation of PILS genes by bZIP transcription factor TGA7 in tomato plant growth.

Auxin plays a pivotal role in plant growth regulation. The PIN-FORMED (PIN) proteins facilitate long-distance polar auxin transport, whereas the recently identified PIN-LIKES (PILS) proteins regulate intracellular auxin homeostasis. However, the auxin transport mechanisms in horticultural crops remain largely unexplored. Here, we identified and characterized PILS genes in tomato (Solanum lycopersicum). Promoter analysis revealed enrichment in TGA[C/T]G motifs, suggesting transcriptional regulation by TGA factors in the bZIP family. Subcellular localization studies confirmed that all tomato PILS proteins localize in the endoplasmic reticulum. PILS2 exhibited the highest expression across examined tissues, and its close homologue PILS6 showed a similar but less pronounced expression pattern. Silencing PILS2 significantly inhibited shoot and root growth. Phylogenetic and expression analyses identified the homologs of Arabidopsis TGA1, TGA3, TGA4, and TGA7 in tomato genome, with tomato TGA7 showing higher expression in roots. Notably, silencing tomato TGA7, but not TGA1, TGA3, or TGA4, strongly impaired shoot and root growth. Molecular assays demonstrated that TGA7 directly binds to the PILS2 promoter to activate its transcription. These findings uncover a TGA7-PILS2 regulatory module that governs plant growth and offer new insights into the function and regulation of PILS genes in tomato.

Transcriptome profiling of eight Zea mays lines identifies genes responsible for the resistance to Fusarium verticillioides

BackgroundThe cultivation of maize (Zea mays L.), one of the most important crops worldwide for food, feed, biofuels, and industrial applications, faces significant constraints due to Fusarium verticillioides, a fungus responsible for severe diseases including seedling blights, stalk rot, and ear rot. Its impact is worsened by the fact that chemical and agronomic measures used to control the infection are often inefficient. Hence, genetic resistance is considered the most reliable resource to reduce the damage. This study aims to elucidate the genetic basis of F. verticillioides resistance in maize.ResultsYoung seedlings of eight divergent maize lines, founders of the MAGIC population, were artificially inoculated with a F. verticillioides strain. Phenotypic analysis and transcriptome sequencing of both control and treated samples identified several hundred differentially expressed genes enriched in metabolic processes associated with terpene synthesis. A WGCNA further refined the pool of genes with potential implications in disease response and found a limited set of hub genes, encoding bZIP and MYB transcription factors, or involved in carbohydrate metabolism, solute transport processes, calcium signaling, and lipid pathways. Finally, additional gene resources were provided by combining transcriptomic data with previous QTL mapping, thereby shedding light on the molecular mechanisms in the maize-F. verticillioides interaction.ConclusionsThe transcriptome profiling of eight divergent MAGIC maize founder lines with contrasting levels of Fusarium verticillioides resistance combined with phenotypic analysis, clarifies the molecular mechanisms underlying the maize-F. verticillioides interaction.

Mechanism of ferroptosis resistance in cancer cells.

Ferroptosis is an iron-dependent cell death characterized by increased intracellular lipid peroxidation. Inducing ferroptosis has shown significant potential in eliminating various malignancies. However, the effectiveness of ferroptosis-based treatments is hampered by the intrinsic or acquired resistance of some tumors. In this review, we delineate the known mechanisms that regulate ferroptosis sensitivity and summarize the therapeutic application of ferroptosis inducers in cancer. Additionally, we discuss the roles of diverse signaling pathways that contribute to ferroptosis resistance in cancer cells, including the glutathione (GSH) and coenzyme Q (CoQ) pathways, NFE2-like bZIP transcription factor 2 (NRF2) antioxidant response, and lipid and iron metabolism. This emerging knowledge may serve as a foundation for developing novel anticancer strategies to overcome ferroptosis resistance.