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Summary: The shape of rice grains not only determines the thousand‐grain weight but also correlates closely with the grain quality.Here we identified an ultra‐large grain accession (ULG) with a thousand‐grain weight exceeding 60 g. The integrated analysis of QTL, BSA, de novo genome assembled, transcription sequencing, and gene editing was conducted to dissect the molecular basis of the ULG formation.The ULG pyramided advantageous alleles from at least four known grain‐shaping genes, OsLG3, OsMADS1, GS3, GL3.1, and one novel locus, qULG2‐b, which encoded a leucine‐rich repeat receptor‐like kinase. The collective impacts of OsLG3, OsMADS1, GS3, and GL3.1 on grain size were confirmed in transgenic plants and near‐isogenic lines. The transcriptome analysis identified 112 genes cooperatively regulated by these four genes that were prominently involved in photosynthesis and carbon metabolism. By leveraging the pleiotropy of these genes, we enhanced the grain yield, appearance, and stress tolerance of rice var. SN265.Beyond showcasing the pyramiding of multiple grain size regulation genes that can produce ULG, our study provides a theoretical framework and valuable genomic resources for improving rice variety by leveraging the pleiotropy of grain size regulated genes. [ABSTRACT FROM AUTHOR]

Summary: The genetic control underlying natural variation in lignin content and composition in trees is not fully understood. We performed a systems genetic analysis to uncover the genetic regulation of lignin biosynthesis in a natural 'SwAsp' population of aspen (Populus tremula) trees.We analyzed gene expression by RNA sequencing (RNA‐seq) in differentiating xylem tissues, and lignin content and composition using Pyrolysis‐GC‐MS in mature wood of 268 trees from 99 genotypes.Abundant variation was observed for lignin content and composition, and genome‐wide association study identified proteins in the pentose phosphate pathway and arabinogalactan protein glycosylation among the top‐ranked genes that are associated with these traits. Variation in gene expression and the associated genetic polymorphism was revealed through the identification of 312 705 local and 292 003 distant expression quantitative trait loci (eQTL). A co‐expression network analysis suggested modularization of lignin biosynthesis and novel functions for the lignin‐biosynthetic CINNAMYL ALCOHOL DEHYDROGENASE 2 and CAFFEOYL‐CoA O‐METHYLTRANSFERASE 3. PHENYLALANINE AMMONIA LYASE 3 was co‐expressed with HOMEOBOX PROTEIN 5 (HB5), and the role of HB5 in stimulating lignification was demonstrated in transgenic trees.The systems genetic approach allowed linking natural variation in lignin biosynthesis to trees´ responses to external cues such as mechanical stimulus and nutrient availability. [ABSTRACT FROM AUTHOR]

Summary Long terminal repeat retroelements (LTR‐REs) have profound effects on DNA methylation and gene regulation. Despite the vast abundance of LTR‐REs in the genome of Moso bamboo (Phyllostachys edulis), an industrial crop in underdeveloped countries, their precise implication of the LTR‐RE mobility in stress response and development remains unknown. We investigated the RNA and DNA products of LTR‐REs in Moso bamboo under various developmental stages and stressful conditions. Surprisingly, our analyses identified thousands of active LTR‐REs, particularly those located near genes involved in stress response and developmental regulation. These genes adjacent to active LTR‐REs exhibited an increased expression under stress and are associated with reduced DNA methylation that is likely affected by the induced LTR‐REs. Moreover, the analyses of simultaneous mapping of insertions and DNA methylation showed that the LTR‐REs effectively alter the epigenetic status of the genomic regions where they inserted, and concomitantly their transcriptional competence which might impact the stress resilience and growth of the host. Our work unveils the unusually strong LTR‐RE mobility in Moso bamboo and its close association with (epi)genetic changes, which supports the co‐evolution of the parasitic DNAs and host genome in attaining stress tolerance and developmental robustness. [ABSTRACT FROM AUTHOR]

SUMMARY The lenticel is a channel‐like structure that facilitates oxygen, carbon dioxide, and water vapor exchange on secondary growth tissue, such as a tree stem. Although the structure of lenticel has been described, there is limited understanding regarding the impact of this secondary structure on secondary growth as well as the cellular and metabolic processes underlying its formation. The study reveals the essential role of the lenticel in the process of tree secondary growth and the cellular and metabolic processes that take place during its formation. Under the stomata, lenticel development occurs when cells divide and differentiate into a structure of disconnected cells with air spaces between them. During lenticel formation, specific metabolic pathways and wax biosynthesis are activated. The SERK (somatic embryogenesis receptor kinase) gene controls lenticel density, and serk1serk3serk5 triple mutants enhance lenticel initiation. The findings shed light on the cellular and metabolic processes involved in lenticel formation, laying the groundwork for further mechanistic elucidation of their development, function, and genetic regulation in trees. [ABSTRACT FROM AUTHOR]

Eukaryotic cells respond to stress by altering coding and non‐coding gene expression programs. Alongside many approaches and regulatory mechanisms, long non‐coding RNAs (lncRNA) are finding a significant place in gene regulation, suggesting an involvement in various cellular processes and pathophysiology. LncRNAs are regulated by many transcription factors, including SMAR1 and p53, which are tumor suppressor genes. SMAR1 inhibits cancer cell metastasis and invasion and is also known to inhibit apoptosis during low‐dose stress in coordination with p53. Data mining analysis suggested that these tumor suppressor genes might coregulate the lncRNA RP11‐431M3.1 in colon cancer cells. Importantly, RP11‐431M3.1 expression was found to be negatively correlated with patient survival rates in a number of cancers. Oxidative stress occurs when an imbalance in the body is caused by reactive oxygen species (ROS). This imbalance is known to be important in the development/pathogenesis of colon cancer. We are researching the role and control of this lncRNA in HCT116 cells under conditions of oxidative stress. We observed a dose‐dependent differential expression of lncRNA upon H2O2 treatment and found that p53 and SMAR1 bind differentially to the promoter in response to the dose of stress inducer used. RP11‐431M3.1 was observed to sponge miR‐138 which has an important target gene, hypoxia‐inducible factor (HIF1A). miR‐138 was observed to bind differentially to RP11‐431M3.1 and HIF1A RNA depending on the dose of oxidative stress. Furthermore, the knockdown of RP11‐431M3.1 decreased the migration and proliferation of colon cancer cells. Our results suggest a previously undescribed regulatory mechanism through which RP11‐431M3.1 is transcriptionally regulated by SMAR1 and p53, target HIF1A through miR‐138, and highlight its potential as a therapeutic and diagnostic marker for cancer. [ABSTRACT FROM AUTHOR]

RNA G‐quadruplex structures (rG4s) play important roles in the regulation of biological processes. So far, all the l‐RNA aptamers developed to target rG4 of interest contain G4 motif itself, raising the question of whether non‐G4‐containing l‐RNA aptamer can be developed to target rG4. Furthermore, it is unclear whether an l‐Aptamer‐based tool can be generated for G4 detection in vitro and imaging in cells. Herein, a new strategy is designed using a low GC content template library to develop a novel non‐G4‐containing l‐RNA aptamer with strong binding affinity and improved binding specificity to rG4 of interest. The first non‐G4‐containing l‐Aptamer, l‐Apt.1‐1, is identified with nanomolar binding affinity to amyloid precursor protein (APP) D‐rG4. l‐Apt.1‐1 is applied to control APP gene expression in cells via targeting APP D‐rG4 structure. Moreover, the first l‐RNA‐based fluorogenic bi‐functional aptamer (FLAP) system is developed, and l‐Apt.1‐1_Pepper is engineered for in vitro detection and cellular imaging of APP D‐rG4. This work provides an original approach for developing non‐G4‐containing l‐RNA aptamer for rG4 targeting, and the novel l‐Apt.1‐1 developed for APP gene regulation, as well as the l‐Apt.1‐1_Pepper generated for imaging of APP rG4 structure can be further used in other applications in vitro and in cells. [ABSTRACT FROM AUTHOR]

Highlights In muscle, digoxin inhibits Na+,K+‐ATPase (NKA) whereas acute exercise can increase NKA gene expression, consistent with training‐induced increased NKA content. We investigated whether oral digoxin increased NKA isoform mRNA expression (qPCR) in muscle at rest, during and post‐exercise in 10 healthy adults, who received digoxin (DIG, 0.25 mg per day) or placebo (CON) for 14 days, in a randomised, double‐blind and cross‐over design. Muscle was biopsied at rest, after cycling 20 min (10 min each at 33%, then 67% V̇O2peak${{\dot{V}}_{{{{\mathrm{O}}}_2}{\mathrm{peak}}}}$), then to fatigue at 90% V̇O2peak${{\dot{V}}_{{{{\mathrm{O}}}_2}{\mathrm{peak}}}}$ and 3 h post‐exercise. No differences were found between DIG and CON for NKA α1–3 or β1–3 isoform mRNA. Both α1 (354%, P = 0.001) and β3 mRNA (P = 0.008) were increased 3 h post‐exercise, with α2 and β1–2 mRNA unchanged, whilst α3 mRNA declined at fatigue (−43%, P = 0.045). In resting muscle, total β mRNA (∑(β1+β2+β3)) increased in DIG (60%, P = 0.025) and also when transcripts for each isoform were normalised to CON then either summed (P = 0.030) or pooled (n = 30, P = 0.034). In contrast, total α mRNA (∑(α1+α2+α3), P = 0.348), normalised then summed (P = 0.332), or pooled transcripts (n = 30, P = 0.717) did not differ with DIG. At rest, NKA α1–2 and β1–2 protein abundances were unchanged by DIG. Post‐exercise, α1 and β1–2 proteins were unchanged, but α2 declined at 3 h (19%, P = 0.020). In conclusion, digoxin did not modify gene expression of individual NKA isoforms at rest or with exercise, indicating NKA gene expression was maintained consistent with protein abundances. However, elevated resting muscle total β mRNA with digoxin suggests a possible underlying β gene‐stimulatory effect. What is the central question of this study? Na+,K+‐ATPase (NKA) in muscle is important for Na+/K+ homeostasis. We investigated whether the NKA‐inhibitor digoxin stimulates increased NKA gene expression in muscle and exacerbates NKA gene responses to exercise in healthy adults. What is the main finding and its importance? Digoxin did not modify exercise effects on muscle NKA α1–3 and β1–3 gene transcripts, which comprised increased post‐exercise α1 and β3 mRNA and reduced α3 mRNA during exercise. However, in resting muscle, digoxin increased NKA total β isoform mRNA expression. Despite inhibitory‐digoxin or acute exercise stressors, NKA gene regulation in muscle is consistent with the maintenance of NKA protein contents. What is the central question of this study?Na+,K+‐ATPase (NKA) in muscle is important for Na+/K+ homeostasis. We investigated whether the NKA‐inhibitor digoxin stimulates increased NKA gene expression in muscle and exacerbates NKA gene responses to exercise in healthy adults.What is the main finding and its importance?Digoxin did not modify exercise effects on muscle NKA α1–3 and β1–3 gene transcripts, which comprised increased post‐exercise α1 and β3 mRNA and reduced α3 mRNA during exercise. However, in resting muscle, digoxin increased NKA total β isoform mRNA expression. Despite inhibitory‐digoxin or acute exercise stressors, NKA gene regulation in muscle is consistent with the maintenance of NKA protein contents. [ABSTRACT FROM AUTHOR]

SUMMARY Long non‐coding RNAs (lncRNAs) play crucial roles in various biological processes in plants. However, the functional mechanism of lncRNAs in fruit ripening, particularly the transition from unripe to ripe stages, remains elusive. One such lncRNA1840, reported by our group, was found to have important role in tomato fruit ripening. In the present study, we gain insight into its functional role in fruit ripening. CRISPR‐Cas9 mediated lncRNA1840 mutants caused the delayed tomato fruit ripening. Notably, loss function of lncRNA1840 did not directly impact ethylene signaling but rather delay ethylene synthesis. Transcriptomic analysis revealed differences in the expression of ripening related genes in lncRNA1840 mutants, suggesting that it is involved in gene regulation of fruit ripening. We used Chromatin Isolation by RNA Purification (ChIRP)‐Seq to identify lncRNA1840 binding sites on chromatin. ChIRP‐seq suggested that lncRNA1840 had occupancy on 40 genes, but none of them is differentially expressed genes in transcriptomic analysis, which indicated lncRNA1840 might indirectly modulate the gene expression. ChIRP‐mass spectrometry analysis identified potential protein interactors of lncRNA1840, Pre‐mRNA processing splicing factor 8, highlighting its involvement in post‐transcriptional regulatory pathways. In summary, lncRNA1840 is key player in tomato plant growth and fruit ripening, with multifaceted roles in gene expression and regulatory networks. [ABSTRACT FROM AUTHOR]

Molt‐based transitions in form are a central feature of insect life that have enabled adaptation to diverse and changing environments. The endocrine regulation of these transitions is well established, but an understanding of their genetic regulation has only recently emerged from insect models. The pupal and adult stages of metamorphosing insects are determined by the stage specifying transcription factors broad‐complex (br) and Ecdysone inducible protein 93 (E93), respectively. A probable larval determinant, chronologically inappropriate metamorphosis (chinmo), has just recently been characterized. Expression of these three transcription factors in the metamorphosing insects is regulated by juvenile hormone with ecdysteroid hormones, and by mutual repression between the stage‐specific transcription factors. This review explores the hypothesis that variations in the onset, duration, and tissue‐specific expression of chinmo, br, and E93 underlie other polyphenisms that have arisen throughout insects, including the castes of social insects, aquatic stages of mayflies, and the neoteny of endoparasites. The mechanisms that constrain how chinmo, br, and E93 expression may vary will also constrain the ways that insect life history may evolve. I find that four types of expression changes are associated with novel insect forms: (1) heterochronic shift in the turnover of expression, (2) expansion or contraction of expression, (3) tissue‐specific expression, and (4) redeployment of stage‐specific expression. While there is more to be learned about chinmo, br, and E93 function in diverse insect taxa, the studies outlined here show that insect stages are modular units in developmental time and a substrate for evolutionary forces to act upon. [ABSTRACT FROM AUTHOR]

Global proliferative arrest (GPA) is a phenomenon in monocarpic plants in which the activity of all aboveground meristems generally ceases in a nearly coordinated manner after the formation of a certain number of fruits. Despite the fact that GPA is a biologically and agriculturally important event, the underlying molecular mechanisms are not well understood. In this study, we attempted to elucidate the molecular mechanism of GPA regulation by identifying the gene responsible for the Arabidopsis mutant fireworks (fiw), causing an early GPA phenotype. Map‐based cloning revealed that the fiw gene encodes CYSTEIN‐RICH RECEPTOR‐LIKE KINASE 14 (CRK14). Genetic analysis suggested that fiw is a missense, gain‐of‐function allele of CRK14. Since overexpression of the extracellular domain of CRK14 resulted in delayed GPA in the wild‐type background, we concluded that CRK14 is involved in GPA regulation. Analysis of double mutants revealed that fiw acts downstream of or independently of the FRUITFULL‐APETALA2 (AP2)/AP2‐like pathway, which was previously reported as an age‐dependent default pathway in GPA regulation. In addition, fiw is epistatic to clv with respect to GPA control. Furthermore, we found a negative effect on WUSCHEL expression in the fiw mutants. These results thus suggest the existence of a novel CRK14‐dependent signaling pathway involved in GPA regulation. [ABSTRACT FROM AUTHOR]

Enhancers are short segments of regulatory DNA that control when and in which cell‐type genes should be turned on in response to a variety of extrinsic and intrinsic signals. At the molecular level, enhancers serve as a genomic scaffold that recruits sequence‐specific transcription factors and co‐activators to facilitate transcription from linked promoters. However, it remains largely unclear how enhancers communicate with appropriate target promoters in the context of higher‐order genome topology. In this review, we discuss recent progress in our understanding of the functional interplay between enhancers, genome topology, and the molecular properties of transcription machineries in gene regulation. We suggest that the activities of transcription hubs are highly regulated through the dynamic rearrangement of enhancer‐promoter and promoter‐promoter connectivity during animal development. [ABSTRACT FROM AUTHOR]

Summary: Grain filling in maize (Zea mays) is intricately linked to cell development, involving the regulation of genes responsible for the biosynthesis of storage reserves (starch, proteins, and lipids) and phytohormones. However, the regulatory network coordinating these biological functions remains unclear.In this study, we identified 1744 high‐confidence target genes co‐regulated by the transcription factors (TFs) ZmNAC128 and ZmNAC130 (ZmNAC128/130) through chromatin immunoprecipitation sequencing coupled with RNA‐seq analysis in the zmnac128/130 loss‐of‐function mutants. We further constructed a hierarchical regulatory network using DNA affinity purification sequencing analysis of downstream TFs regulated by ZmNAC128/130.In addition to target genes involved in the biosynthesis of starch and zeins, we discovered novel target genes of ZmNAC128/130 involved in the biosynthesis of lipids and indole‐3‐acetic acid (IAA). Consistently, the number of oil bodies, as well as the contents of triacylglycerol, and IAA were significantly reduced in zmnac128/130. The hierarchical regulatory network centered by ZmNAC128/130 revealed a significant overlap between the direct target genes of ZmNAC128/130 and their downstream TFs, particularly in regulating the biosynthesis of storage reserves and IAA.Our results indicated that the biosynthesis of storage reserves and IAA is coordinated by a multi‐TFs hierarchical regulatory network in maize endosperm. [ABSTRACT FROM AUTHOR]

Summary: Gene expression is regulated at multiple levels, including RNA processing and DNA methylation/demethylation. How these regulations are controlled remains unclear.Here, through analysis of a suppressor for the OsEIN2 over‐expressor, we identified an RNA recognition motif protein SUPPRESSOR OF EIN2 (SOE). SOE is localized in nuclear speckles and interacts with several components of the spliceosome. We find SOE associates with hundreds of targets and directly binds to a DNA glycosylase gene DNG701 pre‐mRNA for efficient splicing and stabilization, allowing for subsequent DNG701‐mediated DNA demethylation of the transgene promoter for proper gene expression. The V81M substitution in the suppressor mutant protein mSOE impaired its protein stability and binding activity to DNG701 pre‐mRNA, leading to transgene silencing.SOE mutation enhances grain size and yield. Haplotype analysis in c. 3000 rice accessions reveals that the haplotype 1 (Hap 1) promoter is associated with high 1000‐grain weight, and most of the japonica accessions, but not indica ones, have the Hap 1 elite allele.Our study discovers a novel mechanism for the regulation of gene expression and provides an elite allele for the promotion of yield potentials in rice. See also the Commentary on this article by Bazin & Crespi, 243: 1631–1632. [ABSTRACT FROM AUTHOR]

Bamboo cultivation, particularly Moso bamboo (Phyllostachys edulis), holds significant economic importance in various regions worldwide. Bamboo shoot degradation (BSD) severely affects productivity and economic viability. However, despite its agricultural consequences, the molecular mechanisms underlying BSD remain unclear. Consequently, we explored the dynamic changes of BSD through anatomy, physiology and the transcriptome. Our findings reveal ruptured protoxylem cells, reduced cell wall thickness and the accumulation of sucrose and reactive oxygen species (ROS) during BSD. Transcriptomic analysis underscored the importance of genes related to plant hormone signal transduction, sugar metabolism and ROS homoeostasis in this process. Furthermore, BSD appears to be driven by the coexpression regulatory network of senescence‐associated gene transcription factors (SAG‐TFs), specifically PeSAG39, PeWRKY22 and PeWRKY75, primarily located in the protoxylem of vascular bundles. Yeast one‐hybrid and dual‐luciferase assays demonstrated that PeWRKY22 and PeWRKY75 activate PeSAG39 expression by binding to its promoter. This study advanced our understanding of the molecular regulatory mechanisms governing BSD, offering a valuable reference for enhancing Moso bamboo forest productivity. Summary statement: The bamboo shoot degradation occurs first in the protoxylem and impacts phytohormone signalling, starch and sucrose metabolism, as well as reactive oxygen species homoeostasis. PeWRKY22 and PeWRKY75 activate PeSAG39 by binding to its promoters. [ABSTRACT FROM AUTHOR]

Summary: Higher‐order chromatin structure is critical for regulation of gene expression. In plants, light profoundly affects the morphogenesis of emerging seedlings as well as global gene expression to ensure optimal adaptation to environmental conditions. However, the changes and functional significance of chromatin organization in response to light during seedling development are not well documented. We constructed Hi‐C contact maps for the cotyledon, apical hook and hypocotyl of soybean subjected to dark and light conditions. The resulting high‐resolution Hi‐C contact maps identified chromosome territories, A/B compartments, A/B sub‐compartments, TADs (Topologically Associated Domains) and chromatin loops in each organ. We observed increased chromatin compaction under light and we found that domains that switched from B sub‐compartments in darkness to A sub‐compartments under light contained genes that were activated during photomorphogenesis. At the local scale, we identified a group of TADs constructed by gene clusters consisting of different numbers of Small Auxin‐Upregulated RNAs (SAURs), which exhibited strict co‐expression in the hook and hypocotyl in response to light stimulation. In the hypocotyl, RNA polymerase II (RNAPII) regulated the transcription of a SAURs cluster under light via TAD condensation. Our results suggest that the 3D genome is involved in the regulation of light‐related gene expression in a tissue‐specific manner. [ABSTRACT FROM AUTHOR]

Objectives: Studies have investigated miR‐125a for its predictable role in recurrent pregnancy loss (RPL) cases to regulate many biological events required for the maintenance of pregnancy by regulating its confirmed target genes LIFR, ERBB2 and STAT3. Methods: The present study included 40 cases of women with at least two RPLs in ≤20 weeks of gestation against 40 healthy multiparous women without a previous history of abortion. Expression analysis of ERBB2, LIFR, STAT3 and miR‐125a was conducted by quantitative real‐time PCR (qPCR). Results: The expression of miR‐125a was significantly lower in the plasma of RPL cases (P = 0.0001) and showed a significantly increased mean expression level in product of conception (2.56‐fold, P < 0.0001). Among the target gene of miR‐125a, ERBB2 and STAT3 gene expression level was significantly increased (2.58‐fold, P = 0.04; 1.87‐fold, P = 0.025), respectively in RPL cases while the LIFR gene revealed comparable expression (P = 0.64). Furthermore, expression analysis of ERBB2 gene with respect to its regulatory miR‐125a cases depicted a significant association (P = 0.0005). Kaplan–Meier survival analysis revealed cases with low miR‐125a expression had significantly shorter time to miscarriages, (log‐rank P = 0.02). Also, decreased expression of miR‐125a significantly conferred >2‐fold increased risk for RPL (HR = 2.34: P < 0.05). Conclusion: The overall conclusion of the study was that altered miR‐125a expression may cause deregulation in target genes LIFR, ERBB2 and STAT3 resulting in adverse consequence in the outcome of pregnancy. Synopsis: The impact of altered miR‐125a expression causes deregulation in target genes LIFR, ERBB2 and STAT3 that result in deleterious effect in the outcome of the pregnancy. [ABSTRACT FROM AUTHOR]

SUMMARY: Polyploidy is a prominent driver of plant diversification, accompanied with dramatic chromosomal rearrangement and epigenetic changes that affect gene expression. How chromatin interactions within and between subgenomes adapt to ploidy transition remains poorly understood. We generate open chromatin interaction maps for natural hexaploid wheat (AABBDD), extracted tetraploid wheat (AABB), diploid wheat progenitor Aegilops tauschii (DD) and resynthesized hexaploid wheat (RHW, AABBDD). Thousands of intra‐ and interchromosomal loops are de novo established or disappeared in AB subgenomes after separation of D subgenome, in which 37–95% of novel loops are lost again in RHW after merger of D genome. Interestingly, more than half of novel loops are formed by cascade reactions that are triggered by disruption of chromatin interaction between AB and D subgenomes. The interaction repressed genes in RHW relative to DD are expression suppressed, resulting in more balanced expression of the three homoeologs in RHW. The interaction levels of cascade anchors are decreased step‐by‐step. Leading single nucleotide polymorphisms of yield‐ and plant architecture‐related quantitative trait locus are significantly enriched in cascade anchors. The expression of 116 genes interacted with these anchors are significantly correlated with the corresponding traits. Our findings reveal trans‐regulation of intrachromosomal loops by interchromosomal interactions during genome merger and separation in polyploid species. Significance Statement: Understanding the chromatin interaction changes in response to ploidy transition can provide further insight into the role of chromatin loops in regulation of gene expression and phenotypes in polyploidy. We find that the ploidy transition can result in cascaded changes in chromatin interactions, which are associated with balancing homoeologous gene expression and altering the expression of coexpressed genes related to specific phenotypes in polyploids. Many trait‐associated genes interact with quantitative trait loci through these cascaded chromatin interactions. [ABSTRACT FROM AUTHOR]

SUMMARY: Achieving optimally balanced gene expression within synthetic operons requires regulatory elements capable of providing a spectrum of expression levels. In this study, we investigate the expression of gfp reporter gene in tobacco chloroplasts, guided by variants of the plastid atpH 5′ UTR, which harbors a binding site for PPR10, a protein that activates atpH at the posttranscriptional level. Our findings reveal that endogenous tobacco PPR10 confers distinct levels of reporter activation when coupled with the tobacco and maize atpH 5′ UTRs in different design contexts. Notably, high GFP expression was not coupled to the stabilization of monocistronic gfp transcripts in dicistronic reporter lines, adding to the evidence that PPR10 activates translation via a mechanism that is independent of its stabilization of monocistronic transcripts. Furthermore, the incorporation of a tRNA upstream of the UTR nearly abolishes gfp mRNA (and GFP protein), presumably by promoting such rapid RNA cleavage and 5′ exonucleolytic degradation that PPR10 had insufficient time to bind and protect gfp RNA, resulting in a substantial reduction in GFP accumulation. When combined with a mutant atpH 5′ UTR, the tRNA leads to an exceptionally low level of transgene expression. Collectively, this approach allows for tuning of reporter gene expression across a wide range, spanning from a mere 0.02–25% of the total soluble cellular protein. These findings highlight the potential of employing cis‐elements from heterologous species and expand the toolbox available for plastid synthetic biology applications requiring multigene expression at varying levels. Significance Statement: Achieving optimally balanced gene expression within synthetic operons requires regulatory elements capable of providing a spectrum of expression levels. We report posttranscriptional tools to tune gene expression in synthetic Nicotiana tabacum (tobacco) chloroplast operons over the range of 0.02–25% of total soluble cellular protein. [ABSTRACT FROM AUTHOR]

SUMMARY: Advancing chloroplast genetic engineering in Chlamydomonas reinhardtii remains challenging, decades after its first successful transformation. This study introduces the development of a chloroplast‐optimized mNeonGreen fluorescent reporter, enabling in vivo observation through a sixfold increase in fluorescence via context‐aware construct engineering. Our research highlights the influence of transcriptional readthrough and antisense mRNA pairing on post‐transcriptional regulation, pointing to novel strategies for optimizing heterologous gene expression. We further demonstrate the applicability of these insights using an accessible experimentation system using glass‐bead transformation and reestablishment of photosynthesis using psbH mutants, focusing on the mitigation of transcriptional readthrough effects. By characterizing heterologous expression using regulatory elements such as PrrnS, 5′atpA, and 3′ rbcL in a sense‐transcriptional context, we further documented up to twofold improvement in fluorescence levels. Our findings contribute new tools for molecular biology research in the chloroplast and evidence fundamental gene regulation processes that could enable the development of more effective chloroplast engineering strategies. This work not only paves the way for more efficient genetic engineering of chloroplasts but also deepens our understanding of the regulatory mechanisms at play. Significance Statement: In this work, we develop a functional fluorescent reporter for Chlamydomonas chloroplast expression, and found construct context‐effects influencing gene expression through formation of antisense dsRNA. These findings will aid in developing more efficient chloroplast genetic strategies and illuminate aspects of chloroplast gene expression. [ABSTRACT FROM AUTHOR]

SUMMARY: Global wheat production amounted to >780 MMT during 2022–2023 whose market size are valued at >$128 billion. Wheat is highly susceptible to high‐temperature stress (HTS) throughout the life cycle and its yield declines 5–7% with the rise in each degree of temperature. Previously, we reported an array of HTS‐response markers from a resilient wheat cv. Unnat Halna and described their putative role in heat acclimation. To complement our previous results and identify the key determinants of thermotolerance, here we examined the cytoplasmic proteome of a sensitive cv. PBW343. The HTS‐triggered metabolite reprograming highlighted how proteostasis defects influence the formation of an integrated stress‐adaptive response. The proteomic analysis identified several promising HTS‐responsive proteins, including a NACα18 protein, designated TaNACα18, whose role in thermotolerance remains unknown. Dual localization of TaNACα18 suggests its crucial functions in the cytoplasm and nucleus. The homodimerization of TaNACα18 anticipated its function as a transcriptional coactivator. The complementation of TaNACα18 in yeast and overexpression in wheat demonstrated its role in thermotolerance across the kingdom. Altogether, our results suggest that TaNACα18 imparts tolerance through tight regulation of gene expression, cell wall remodeling and activation of cell defense responses. [ABSTRACT FROM AUTHOR]

CASK (MIM#300172), encoding a calcium/calmodulin‐dependent serine protein kinase, is crucial for synaptic transmission and gene regulation during neural development. Pathogenic variants of CASK are known to cause several neurodevelopmental disorders, including X‐linked intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH). This study introduces a novel, de novo synonymous CASK variant (NM_001367721.1: c.1737G>A, p.(Glu579=)), discovered in a male patient diagnosed with MICPCH, characterized by microcephaly, developmental delay, visual impairment, and myoclonic seizures. The variant disrupts a donor splice‐site at the end of exon 18. Transcriptomic analysis of blood identified 12 different CASK transcripts secondary to the synonymous variant. Nearly one third of these transcripts were predicted to result in nonsense mediated decay or protein degradation. Protein modeling revealed structural alterations in the PDZ functional domain of CASK, due to exon 18 deletion. Our findings highlight the utility of transcriptomic analysis in demonstrating the underlying disease mechanism in neurodevelopmental disorders. [ABSTRACT FROM AUTHOR]

Intracellular oligonucleotide delivery possesses unparalleled potential for precise regulation of pathogenic gene expression and alteration of cell destiny. However, limited by its feeble resistance against humoral environment, hindered intracellular transportation, and lysosomal phagocytosis, oligonucleotide therapy remains a formidable challenge. The discovery of cationic peptides has provided innovative insights for the effective delivery of oligonucleotides, yet the stable, efficient, and convenient assembly of peptides and oligonucleotides remains an elusive goal, referred to as the “Holy Grail” challenge in the field. Addressing this challenge, it has pioneered the development of a straightforward and highly efficient engineering carrier‐free covalent peptide‐oligonucleotide nano‐conjugates (PONs) through a mild click reaction. Notably, this PONs can realize self‐assemble into nanoparticles under amphiphilic electrostatic interactions, which exhibits significant RNase resistance and surprisingly effective intracellular oligonucleotide delivery as well as lysosomal escape. Based on this strategy, a PONs named CPP‐(DOPA)6‐miRNA‐223 is synthesized, which demonstrates rapid and effective cellular uptake, swift lysosomal escape in macrophage, remarkable accumulation in inflammatory regions and excellent therapeutic effect in an inflammatory arthritis model. Therefore, this work may provide a breakthrough for the clinical application of all oligonucleotide delivery therapies and expanding the applications in gene therapy. [ABSTRACT FROM AUTHOR]

Dysfunctional RNA‐binding proteins (RBPs) have been implicated in several geriatric diseases, including Alzheimer's disease (AD). However, little is known about the nuclear molecular actions and cooperative functions mediated by RBPs that affect gene regulation in sporadic AD or aging. In the present study, we investigated aging‐ and AD‐associated changes in the expression of PSF and G3BP2, which are representative RBPs associated with sex hormone activity. We determined that both PSF and G3BP2 levels were decreased in aged brains compared to young brains of mice. RNA sequencing (RNA‐seq) analysis of human neuronal cells has shown that PSF is responsible for neuron‐specific functions and sustains cell viability. In addition, we showed that PSF interacted with G3BP2 in the nucleus and stress granules (SGs) at the protein level. Moreover, PSF–mediated gene regulation at the RNA level correlated with G3BP2. Interestingly, PSF and G3BP2 target genes are associated with AD development. Mechanistically, quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) analysis demonstrated that the interaction of RBPs with the pre‐mRNA of target genes enhanced post‐transcriptional mRNA stability, suggesting a possible role for these RBPs in preserving neuronal cell viability. Notably, in the brains of patients with sporadic AD, decreased expression of PSF and G3BP2 in neurons was observed compared to non‐AD patients. Overall, our findings suggest that the cooperative action of PSF and G3BP2 in the nucleus is important for preventing aging and AD development. [ABSTRACT FROM AUTHOR]

Cells have evolved a robust and highly regulated DNA damage response to preserve their genomic integrity. Although increasing evidence highlights the relevance of RNA regulation, our understanding of its impact on a fully efficient DNA damage response remains limited. Here, through a targeted CRISPR-knockout screen, we identify RNA-binding proteins and modifiers that participate in the p53 response. Among the top hits, we find the m6A reader YTHDC1 as a master regulator of p53 expression. YTHDC1 binds to the transcription start sites of TP53 and other genes involved in the DNA damage response, promoting their transcriptional elongation. YTHDC1 deficiency also causes the retention of introns and therefore aberrant protein production of key DNA damage factors. While YTHDC1-mediated intron retention requires m6A, TP53 transcriptional pause-release is promoted by YTHDC1 independently of m6A. Depletion of YTHDC1 causes genomic instability and aberrant cancer cell proliferation mediated by genes regulated by YTHDC1. Our results uncover YTHDC1 as an orchestrator of the DNA damage response through distinct mechanisms of co-transcriptional mRNA regulation. Synopsis: The DNA damage response (DDR) is critical to preserve genomic integrity, and p53 plays a central role in this process. Here, we show that YTHDC1 controls the correct expression of TP53 mRNA as well as splicing of key DDR factors in a m6A-independent and -dependent manner, respectively. CRISPR knockout screening focused on RNA regulators identifies YTHDC1 as required for p53-dependent reporter gene activation. YTHDC1 directly controls TP53 expression through promoter-proximal RNAPII pause-release in a m6A-independent mechanism. In addition, YTHDC1 directly regulates the efficient splicing of ATR, BIRC6 and SETX transcripts in a m6A-dependent manner. Depletion of YTHDC1 results in accumulated DNA damage, reduced proliferation and tumorigenicity of lung cancer cells, caused by deregulation of DDR factors. m6A reader YTHDC1 contributes to genome integrity by promoting p53 expression and controling pre-mRNA splicing of key DNA damage response regulators. [ABSTRACT FROM AUTHOR]

Background and Purpose: Chymotrypsin is a pancreatic protease secreted into the lumen of the small intestine to digest food proteins. We hypothesized that chymotrypsin activity may be found close to epithelial cells and that chymotrypsin signals to them via protease‐activated receptors (PARs). We deciphered molecular pharmacological mechanisms and gene expression regulation for chymotrypsin signalling in intestinal epithelial cells. Experimental Approach: The presence and activity of chymotrypsin were evaluated by Western blot and enzymatic activity tests in the luminal and mucosal compartments of murine and human gut samples. The ability of chymotrypsin to cleave the extracellular domain of PAR1 or PAR2 was assessed using cell lines expressing N‐terminally tagged receptors. The cleavage site of chymotrypsin on PAR1 and PAR2 was determined by HPLC–MS analysis. The chymotrypsin signalling mechanism was investigated in CMT93 intestinal epithelial cells by calcium mobilization assays and Western blot analyses of (ERK1/2) phosphorylation. The transcriptional consequences of chymotrypsin signalling were analysed on colonic organoids. Key Results: We found that chymotrypsin was present and active in the vicinity of the colonic epithelium. Molecular pharmacological studies have shown that chymotrypsin cleaves both PAR1 and PAR2 receptors. Chymotrypsin activated calcium and ERK1/2 signalling pathways through PAR2, and this pathway promoted interleukin‐10 (IL‐10) up‐regulation in colonic organoids. In contrast, chymotrypsin disarmed PAR1, preventing further activation by its canonical agonist, thrombin. Conclusion and Implications: Our results highlight the ability of chymotrypsin to signal to intestinal epithelial cells via PARs, which may have important physiological consequences in gut homeostasis. [ABSTRACT FROM AUTHOR]

SUMMARY Polycomb group (PcG) proteins are essential gene repressors in higher eukaryotes. However, how PcG proteins mediate transcriptional regulation of specific genes remains unknown. LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), as a component of Polycomb Repression Complexes (PRC), epigenetically mediates several plant developmental processes together with PcG proteins. We observed physical interaction between MYB73 and LHP1 in vitro and in vivo. Genetic analysis indicated that myb73 mutants showed slightly late flowering, and the lhp1‐3 myb73‐2 double mutant exhibited delayed flowering and downregulated FT expression compared to lhp1‐3. Chromatin immunoprecipitation and yeast one‐hybrid assays revealed that MYB73 preferentially binds to the FT promoter. Additionally, our protoplast transient assays demonstrated that MYB73 activates to the FT promoter. Interestingly, the LHP1‐MYB73 interaction is necessary to repress the FT promoter, suggesting that the LHP1‐MYB73 interaction prevents FT activation by MYB73 in Arabidopsis. Our results show an example in which a chromatin regulator affects transcriptional regulation by negatively regulating a transcription factor through direct interaction. [ABSTRACT FROM AUTHOR]

Under the long‐term pressure overload stimulation, the heart experiences embryonic gene activation, leading to myocardial hypertrophy and ventricular remodelling, which can ultimately result in the development of heart failure. Identifying effective therapeutic targets is crucial for the prevention and treatment of myocardial hypertrophy. Histone lysine lactylation (HKla) is a novel post‐translational modification that connects cellular metabolism with epigenetic regulation. However, the specific role of HKla in pathological cardiac hypertrophy remains unclear. Our study aims to investigate whether HKla modification plays a pathogenic role in the development of cardiac hypertrophy. The results demonstrate significant expression of HKla in cardiomyocytes derived from an animal model of cardiac hypertrophy induced by transverse aortic constriction surgery, and in neonatal mouse cardiomyocytes stimulated by Ang II. Furthermore, research indicates that HKla is influenced by glucose metabolism and lactate generation, exhibiting significant phenotypic variability in response to various environmental stimuli. In vitro experiments reveal that exogenous lactate and glucose can upregulate the expression of HKla and promote cardiac hypertrophy. Conversely, inhibition of lactate production using glycolysis inhibitor (2‐DG), LDH inhibitor (oxamate) and LDHA inhibitor (GNE‐140) reduces HKla levels and inhibits the development of cardiac hypertrophy. Collectively, these findings establish a pivotal role for H3K18la in pathological cardiac hypertrophy, offering a novel target for the treatment of this condition. [ABSTRACT FROM AUTHOR]

The pathogenesis of Hirschsprung's disease (HSCR) is complex. Recently, it has been found that histone modifications can alter genetic susceptibility and play important roles in the proliferation, differentiation and migration of neural crest cells. H3K36 methylation plays a significant role in gene transcriptional activation and expression, but its pathogenic mechanism in HSCR has not yet been studied. This study aimed to elucidate its role and molecular mechanism in HSCR. Western blot analysis, immunohistochemistry (IHC) and reverse transcription‐quantitative PCR (RT‒qPCR) were used to investigate H3K36 methylation and methyltransferase levels in dilated and stenotic colon tissue sections from children with. We confirm that SMYD2 is the primary cause of differential H3K36 methylation and influences cell proliferation and migration in HSCR. Subsequently, quantitative detection of m6A RNA methylation revealed that SMYD2 can alter m6A methylation levels. Western blot analysis, RT‐qPCR, co‐immunoprecipitation (co‐IP), and immunofluorescence colocalization were utilized to confirm that SMYD2 can regulate METTL3 expression and affect m6A methylation, affecting cell proliferation and migration. These results confirm that the H3K36 methyltransferase SMYD2 can affect cell proliferation and migration in Hirschsprung's disease by regulating METTL3. Our study suggested that H3K36 methylation plays an important role in HSCR, confirming that the methyltransferase SMYD2 can affect m6A methylation levels and intestinal nervous system development by regulating METTL3 expression. [ABSTRACT FROM AUTHOR]

RNA splicing is crucial in the multilayer regulatory networks for gene expression, making functional interactions with DNA‐ and other RNA‐processing machineries in the nucleus. However, these established couplings are all major spliceosome‐related; whether the minor spliceosome is involved remains unclear. Here, through affinity purification using Drosophila lysates, an interaction is identified between the minor spliceosomal 65K/RNPC3 and ANKRD11, a cofactor of histone deacetylase 3 (HDAC3). Using a CRISPR/Cas9 system, Deletion strains are constructed and found that both Dm65KΔ/Δ and Dmankrd11Δ/Δ mutants have reduced histone deacetylation at Lys9 of histone H3 (H3K9) and Lys5 of histone H4 (H4K5) in their heads, exhibiting various neural‐related defects. The 65K‐ANKRD11 interaction is also conserved in human cells, and the HsANKRD11 middle‐uncharacterized domain mediates Hs65K association with HDAC3. Cleavage under targets and tagmentation (CUT&Tag) assays revealed that HsANKRD11 is a bridging factor, which facilitates the synergistic common chromatin‐binding of HDAC3 and Hs65K. Knockdown (KD) of HsANKRD11 simultaneously decreased their common binding, resulting in reduced deacetylation of nearby H3K9. Ultimately, this study demonstrates that expression changes of many genes caused by HsANKRD11‐KD are due to the decreased common chromatin‐binding of HDAC3 and Hs65K and subsequently reduced deacetylation of H3K9, illustrating a novel and conserved coupling mechanism that links the histone deacetylation with minor spliceosome for the regulation of gene expression. [ABSTRACT FROM AUTHOR]

The chromatinisation of DNA by nucleoid‐associated proteins (NAPs) in archaea ‘formats’ the genome structure in profound ways, revealing both striking differences and analogies to eukaryotic chromatin. However, the extent to which archaeal NAPs actively regulate gene expression remains poorly understood. The dawn of quantitative chromatin mapping techniques and first NAP‐specific occupancy profiles in different archaea promise a more accurate view. A picture emerges where in diverse archaea with very different NAP repertoires chromatin maintains access to regulatory motifs including the gene promoter independently of transcription activity. Our re‐analysis of genome‐wide occupancy data of the crenarchaeal NAP Cren7 shows that these chromatin‐free regions are flanked by increased Cren7 binding across the transcription start site. While bacterial NAPs often form heterochromatin‐like regions across islands with xenogeneic genes that are transcriptionally silenced, there is little evidence for similar structures in archaea and data from Haloferax show that the promoters of xenogeneic genes remain accessible. Local changes in chromatinisation causing wide‐ranging effects on transcription restricted to one chromosomal interaction domain (CID) in Saccharolobus islandicus hint at a higher‐order level of organisation between chromatin and transcription. The emerging challenge is to integrate results obtained at microscale and macroscale, reconciling molecular structure and function with dynamic genome‐wide chromatin landscapes. [ABSTRACT FROM AUTHOR]

Sessile organisms, such as plants, developed various ways to sense and respond to external and internal stimuli to maximize their fitness through evolutionary time. Transcripts and protein regulation are, among many, the main mechanisms that plants use to respond to environmental changes. SKIP protein is one such, presenting an SNKW interacting domain, which is highly conserved among eukaryotes, where SKI interacting protein acts in regulating key processes.In the present work, many bioinformatics tools, such as phylogenetic relationships, gene structure, physical–chemical properties, conserved motifs, prediction of regulatory cis‐elements, chromosomal localization, and protein–protein interaction network, were used to better understand the genome‐wide SNW/SKIP domain‐containing proteins.In total, 28 proteins containing the SNW/SKIP domain were identified in different plant species, including plants of agronomic interest. Two main protein clusters were formed in phylogenetic analysis, and gene structure analysis revealed that, in general, the coding region had no introns. Also, expression of these genes is possibly induced by abiotic stress stimuli. Primary structure analysis of the proteins revealed the existence of an evolutionarily conserved functional unit. But physicochemical properties show that proteins containing the SNW/SKIP domain are commonly unstable under in vivo conditions.In addition, the protein network, demonstrated that SKIP homologues could act by modulating plant fitness through gene expression regulation at the transcriptional and post‐transcriptional levels. This could be corroborated by the expression number of gene copies of SKIP proteins in many species, highlighting it's crucial role in plant development and tolerance through the course of evolution. [ABSTRACT FROM AUTHOR]

The relationship between aging and RNA biogenesis and trafficking is attracting growing interest, yet the precise mechanisms are unknown. The THO complex is crucial for mRNA cotranscriptional maturation and export. Herein, we report that the THO complex is closely linked to the regulation of lifespan. Deficiencies in Hpr1 and Tho2, components of the THO complex, reduced replicative lifespan (RLS) and are linked to a novel Sir2‐independent RLS control pathway. Although transcript sequestration in hpr1Δ or tho2Δ mutants was countered by exosome component Rrp6, loss of this failed to mitigate RLS defects in hpr1Δ. However, RLS impairment in hpr1Δ or tho2Δ was counteracted by the additional expression of Nrd1‐specific mutants that interacted with Rrp6. This effect relied on the interaction of Nrd1, a transcriptional regulator of aging‐related genes, including ribosome biogenesis or RNA metabolism genes, with RNA polymerase II. Nrd1 overexpression reduced RLS in a Tho2‐dependent pathway. Intriguingly, Tho2 deletion mirrored Nrd1 overexpression effects by inducing arbitrary Nrd1 chromatin binding. Furthermore, our genome‐wide ChIP‐seq analysis revealed an increase in the recruitment of Nrd1 to translation‐associated genes, known to be related to aging, upon Tho2 loss. Taken together, these findings underscore the importance of Tho2‐mediated Nrd1 escorting in the regulation of lifespan pathway through transcriptional regulation of aging‐related genes. [ABSTRACT FROM AUTHOR]

Abiotic stresses encompass different environmental stimuli and constantly affect plant sustainability throughout their lifetime. Plants have developed several complex mechanisms to respond against these abiotic stresses. Studies have shown that microRNAs (miRNAs) effectively reduce stress‐responsive genes that significantly help plants tolerate abiotic stresses such as drought, salinity, temperature, and heavy metals. The regulation of such genes by miRNAs not only aids in plant growth and development but also controls physiological processes such as identifying floral organs, leaf morphogenesis, and root development. As per the information, miRNA plays an important role in stress regulation and regulates homeostasis in mangrove plants such as Rhizophore apiculata. Several modern technologies and approaches have been developed to determine these stress response miRNAs. The targeted genes of miRNAs are transcription factors that further control a set of down and upstream genes to affect physiological response. This paper explores the miRNAs found in a mangrove plant Avicennia marina. The plant contains many miRNAs and knowledge of miRNAs – their development, roles, functions, and target genes under abiotic stress conditions. [ABSTRACT FROM AUTHOR]

The tumor suppressor p14/19ARF regulates ribosomal RNA (rRNA) synthesis by controlling the nucleolar localization of Transcription Termination Factor 1 (TTF1). However, the role played by TTF1 in regulating the rRNA genes and in potentially controlling growth has remained unclear. We now show that TTF1 expression regulates cell growth by determining the cellular complement of ribosomes. Unexpectedly, it achieves this by acting as a "roadblock" to synthesis of the noncoding LncRNA and pRNA that we show are generated from the "Spacer Promoter" duplications present upstream of the 47S pre‐rRNA promoter on the mouse and human ribosomal RNA genes. Unexpectedly, the endogenous generation of these noncoding RNAs does not induce CpG methylation or gene silencing. Rather, it acts in cis to suppress 47S preinitiation complex formation and hence de novo pre‐rRNA synthesis by a mechanism reminiscent of promoter interference or occlusion. Taken together, our data delineate a pathway from p19ARF to cell growth suppression via the regulation of ribosome biogenesis by noncoding RNAs and validate a key cellular growth law in mammalian cells. [ABSTRACT FROM AUTHOR]

TAD boundaries are genomic elements that separate biological processes in neighboring domains by blocking DNA loops that are formed through Cohesin‐mediated loop extrusion. Most TAD boundaries consist of arrays of binding sites for the CTCF protein, whose interaction with the Cohesin complex blocks loop extrusion. TAD boundaries are not fully impermeable though and allow a limited amount of inter‐TAD loop formation. Based on the reanalysis of Nano‐C data, a multicontact Chromosome Conformation Capture assay, we propose a model whereby clustered CTCF binding sites promote the successive stalling of Cohesin and subsequent dissociation from the chromatin. A fraction of Cohesin nonetheless achieves boundary read‐through. Due to a constant rate of Cohesin dissociation elsewhere in the genome, the maximum length of inter‐TAD loops is restricted though. We speculate that the DNA‐encoded organization of stalling sites regulates TAD boundary permeability and discuss implications for enhancer–promoter loop formation and other genomic processes. [ABSTRACT FROM AUTHOR]

Changes in the cellular redox balance that occur during plant responses to unfavourable environmental conditions significantly affect a myriad of redox‐sensitive processes, including those that impact on the epigenetic state of the chromatin. Various epigenetic factors, like histone modifying enzymes, chromatin remodelers, and DNA methyltransferases can be targeted by oxidative posttranslational modifications. As their combined action affects the epigenetic regulation of gene expression, they form an integral part of plant responses to (a)biotic stress. Epigenetic changes triggered by unfavourable environmental conditions are intrinsically linked with primary metabolism that supplies intermediates and donors, such acetyl‐CoA and S‐adenosyl‐methionine, that are critical for the epigenetic decoration of histones and DNA. Here, we review the recent advances in our understanding of redox regulation of chromatin remodelling, dynamics of epigenetic marks, and the interplay between epigenetic control of gene expression, redox signalling and primary metabolism within an (a)biotic stress context. Summary statement: Unfavourable environmental conditions impact the epigenetic state of chromatin. Oxidative posttranslational modifications of epigenetic factors are important determinants of epigenetic regulation of gene expression during plant responses to (a)biotic stress. [ABSTRACT FROM AUTHOR]

A stoma forms by a series of asymmetric divisions of stomatal lineage precursor cell and the terminal division of a guard mother cell (GMC). GMC division is restricted to once through genetic regulation mechanisms. Here, we show that nitric oxide (NO) is involved in the regulation of the GMC division. NO donor treatment results in the formation of single guard cells (SGCs). SGCs are also produced in plants that accumulate high NO, whereas clustered guard cells (GCs) appear in plants with low NO accumulation. NO treatment promotes the formation of SGCs in the stomatal signalling mutants sdd1, epf1 epf2, tmm1, erl1 erl2 and er erl1 erl2, reduces the cell number per stomatal cluster in the fama‐1 and flp1 myb88, but has no effect on stomatal of cdkb1;1 cyca2;234. Aminocyclopropane‐1‐carboxylic acid (ACC), a positive regulator of GMC division, reduces the NO‐induced SGC formation. Further investigation found NO inhibits ACC synthesis by repressing the expression of several ACC SYNTHASE (ACS) genes, and in turn ACC represses NO accumulation by promoting the expression of HEMOGLOBIN 1 (HB1) encoding a NO scavenger. This work shows NO plays a role in the regulation of GMC division by modulating ACC accumulation in the Arabidopsis cotyledon. Summary statement: Nitric oxide is able to repress the terminal division of guard mother cell (GMC) by reducing the accumulation of aminocyclopropane‐1‐carboxylic acid which is a positive regulator of GMC division. [ABSTRACT FROM AUTHOR]

The hypothalamic–pituitary–adrenal axis is an extremely dynamic system with a combination of both circadian and ultradian oscillations. This state of 'continuous dynamic equilibration' provides a platform that is able to anticipate events, is sensitive in its response to stressors, remains robust during perturbations of both the internal and external environments and shows plasticity to adapt to a changed environment. In this review, we describe these oscillations of glucocorticoid (GC) hormones and why they are so important for GC‐dependent gene activation in the brain and liver, and their consequent effects on the regulation of synaptic and memory function as well as appetite control and metabolic regulation. Abnormalities of mood, appetite and metabolic regulation are well‐known consequences of GC therapy, and we suggest that the pattern of GC treatment and hormone replacement should be a much higher priority for endocrinologists and the pharmaceutical industry. One of the major impediments to our research on the importance of these cortisol rhythms in our patients has been our inability to measure repeated levels of hormones across the day in patients in their home or work surroundings. We describe how new wearable methodologies now allow the measurement of 24‐h cortisol profiles – including during sleep – and will enable us to define physiological normality and allow us both to develop better diagnostic tests and inform, at an individual patient level, how to improve replacement therapy. [ABSTRACT FROM AUTHOR]

Deep sowing is a traditional method for drought resistance in maize production, and mesocotyl elongation is strongly associated with the ability of maize to germinate from deep soil. However, little is known about the functional genes and mechanisms regulating maize mesocotyl elongation. In the present study, we identified a plant‐specific SIMILAR TO RCD‐ONE (SRO) protein family member, ZmSRO1e, involved in maize mesocotyl elongation. The expression of ZmSRO1e is strongly inhibited upon transfer from dark to white light. The loss‐of‐function zmsro1e mutant exhibited a dramatically shorter mesocotyl than the wild‐type in both constant light and darkness, while overexpression of ZmSRO1e significantly promoted mesocotyl elongation, indicating that ZmSRO1e positively regulates mesocotyl elongation. We showed that ZmSRO1e physically interacted with ZmbZIP61, an ortholog of Arabidopsis ELONGATED HYPOCOTYL 5 (HY5) and showed a function similar to that of HY5 in regulating photomorphogenesis. We found that ZmSRO1e repressed the transcriptional activity of ZmbZIP61 toward target genes involved in the regulation of cell expansion, such as ZmEXPB4 and ZmEXPB6, by interfering with the binding of ZmbZIP61 to the promoters of target genes. Our results provide a new understanding of the mechanism by which SRO regulates photomorphogenesis and highlight its potential application in deep sowing‐resistant breeding. [ABSTRACT FROM AUTHOR]

The sesquiterpene lactone artemisinin is an important anti‐malarial component produced by the glandular secretory trichomes of sweet wormwood (Artemisia annua L.). Light was previously shown to promote artemisinin production, but the underlying regulatory mechanism remains elusive. In this study, we demonstrate that ELONGATED HYPOCOTYL 5 (HY5), a central transcription factor in the light signaling pathway, cannot promote artemisinin biosynthesis on its own, as the binding of AaHY5 to the promoters of artemisinin biosynthetic genes failed to activate their transcription. Transcriptome analysis and yeast two‐hybrid screening revealed the B‐box transcription factor AaBBX21 as a potential interactor with AaHY5. AaBBX21 showed a trichome‐specific expression pattern. Additionally, the AaBBX21–AaHY5 complex cooperatively activated transcription from the promoters of the downstream genes AaGSW1, AaMYB108, and AaORA, encoding positive regulators of artemisinin biosynthesis. Moreover, AaHY5 and AaBBX21 physically interacted with the A. annua E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1). In the dark, AaCOP1 decreased the accumulation of AaHY5 and AaBBX21 and repressed the activation of genes downstream of the AaHY5–AaBBX21 complex, explaining the enhanced production of artemisinin upon light exposure. Our study provides insights into the central regulatory mechanism by which light governs terpenoid biosynthesis in the plant kingdom. [ABSTRACT FROM AUTHOR]

The biosynthesis of cellulose, lignin, and hemicelluloses in plant secondary cell walls (SCWs) is regulated by a hierarchical transcriptional regulatory network. This network features orthologous transcription factors shared between poplar and Arabidopsis, highlighting a foundational similarity in their genetic regulation. However, knowledge on the discrepant behavior of the transcriptional‐level molecular regulatory mechanisms between poplar and Arabidopsis remains limited. In this study, we investigated the function of PagMYB128 during wood formation and found it had broader impacts on SCW formation compared to its Arabidopsis ortholog, AtMYB103. Transgenic poplar trees overexpressing PagMYB128 exhibited significantly enhanced xylem development, with fiber cells and vessels displaying thicker walls, and an increase in the levels of cellulose, lignin, and hemicelluloses in the wood. In contrast, plants with dominant repression of PagMYB128 demonstrated the opposite phenotypes. RNA sequencing and reverse transcription – quantitative polymerase chain reaction showed that PagMYB128 could activate SCW biosynthetic gene expression, and chromatin immunoprecipitation along with yeast one‐hybrid, and effector–reporter assays showed this regulation was direct. Further analysis revealed that PagSND1 (SECONDARY WALL‐ASSOCIATED NAC‐DOMAIN PROTEIN1) directly regulates PagMYB128 but not cell wall metabolic genes, highlighting the pivotal role of PagMYB128 in the SND1‐driven regulatory network for wood development, thereby creating a feedforward loop in SCW biosynthesis. [ABSTRACT FROM AUTHOR]

SUMMARY: Strigolactones (SL) function as plant hormones in control of multiple aspects of plant development, mostly via the regulation of gene expression. Immediate early‐gene regulation by SL remains unexplored due to difficulty in dissecting early from late gene expression responses to SL. We used synthetic SL, rac‐GR24 treatment of protoplasts and RNA‐seq to explore early SL‐induced changes in gene expression over time (5–180 minutes) and discovered rapid, dynamic and SL receptor D14‐dependent regulation of gene expression in response to rac‐GR24. Importantly, we discovered a significant dependence of SL signalling on chromatin remodelling processes, as the induction of a key SL‐induced transcription factor BRANCHED1 requires the SWI/SNF chromatin remodelling ATPase SPLAYED (SYD) and leads to upregulation of a homologue SWI/SNF ATPase BRAHMA. ATAC‐seq profiling of genome‐wide changes in chromatin accessibility in response to rac‐GR24 identified large‐scale changes, with over 1400 differentially accessible regions. These changes in chromatin accessibility often precede transcriptional changes and are likely to harbour SL cis‐regulatory elements. Importantly, we discovered that this early and extensive modification of the chromatin landscape also requires SYD. This study, therefore, provides evidence that SL signalling requires regulation of chromatin accessibility, and it identifies genomic locations harbouring likely SL cis‐regulatory sequences. Significance Statement: We have identified that the significant transcriptomic reprogramming by rac‐GR24 requires extensive changes to chromatin accessibility at over a thousand locations throughout the genome. We showed that two chromatin remodellers, SPLAYED and BRAHMA, are involved in this response. Our findings discovered a new component of gene regulation by the plant hormone strigolactone. [ABSTRACT FROM AUTHOR]

Background: The specific role of oxidative stress (OS) in vitiligo and alopecia areata (AA) remains unclear. The aim of this study was to analyze and identify the key markers of OS in vitiligo and AA by bioinformatics. Methods: We obtained vitiligo and AA datasets from gene expression omnibus (GEO) database. The difference‐expressed genes of vitiligo and AA were identified by differential analysis, and the functions of difference‐expressed genes were identified by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) enrichment analysis. Subsequently, Veen package was used to obtain the intersection genes of OS‐related genes with vitiligo and AA. Finally, we used CIBERSORT to assess the infiltration of immune cells in vitiligo and AA. Results: Through enrichment analysis, we found that vitiligo and AA were mainly enriched in cell cycle and cell adhesion molecular channels. We identified KLB and EIF3C as key genes in OS regulation of vitiligo and AA, and found that KLB and EIF3C participate in disease progression by regulating T cells and neutrophils. Conclusions: According to our findings, KLB and EIF3C play a crucial role in the progression and development of vitiligo and AA, which have been identified as biomarkers and target for early diagnosis of patients. [ABSTRACT FROM AUTHOR]

The inflammatory response is tightly regulated to eliminate invading pathogens and avoid excessive production of inflammatory mediators and tissue damage. Caspase‐8 is a cysteine protease that is involved in programmed cell death. Here we show the TRIF‐RIPK1‐Caspase‐8 is required for LPS‐induced CYLD degradation in macrophages. TRIF functions in the upstream of RIPK1. The homotypic interaction motif of TRIF and the death domain of RIPK1 are essential for Caspase‐8 activation. Caspase‐8 cleaves CYLD and the D235A mutant is resistant to the protease activity of Caspase‐8. TRIF and RIPK1 serve as substrates of Capase‐8 in vitro. cFLIP interacts with Caspase‐8 to modulate its protease activity on CYLD and cell death. Deficiency in TRIF, Caspase‐8 or CYLD can lead to a decrease or increase in the expression of genes encoding inflammatory cytokines. Together, the TRIF‐Caspase‐8 and CYLD play opposite roles in the regulation of TLR4 signalling. [ABSTRACT FROM AUTHOR]

This article presents a study on the distribution of cytochrome P450 (CYP450) alleles in the Danish population. CYP450 enzymes are important for drug metabolism, and genetic variations in the genes encoding these enzymes can impact drug response. The study compared genotype data from different genotyping platforms and found that the CYP2C19*17 and CYP2C9*2 alleles were more common than the CYP2C19*2 and CYP2C9*3 alleles. The results provide valuable insights into the genetic variability of these enzymes in the Danish population and suggest that the Illumina GSA platform could be useful for identifying drug-gene interactions. [Extracted from the article]

To survive in the host, pathogenic bacteria need to be able to react to the unfavorable conditions that they encounter, like low pH, elevated temperatures, antimicrobial peptides and many more. These conditions may lead to unfolding of envelope proteins and this may be lethal. One of the mechanisms through which bacteria are able to survive these conditions is through the protease/foldase activity of the high temperature requirement A (HtrA) protein. The gut pathogen Clostridioides difficile encodes one HtrA homolog that is predicted to contain a membrane anchor and a single PDZ domain. The function of HtrA in C. difficile is hitherto unknown but previous work has shown that an insertional mutant of htrA displayed elevated toxin levels, less sporulation and decreased binding to target cells. Here, we show that HtrA is membrane associated and localized on the surface of C. difficile and characterize the requirements for proteolytic activity of recombinant soluble HtrA. In addition, we show that the level of HtrA in the bacteria heavily depends on its proteolytic activity. Finally, we show that proteolytic activity of HtrA is required for survival under acidic conditions. [ABSTRACT FROM AUTHOR]

Pioneer transcription factors, by virtue of their ability to target nucleosomal DNA in silent chromatin, play crucial roles in eliciting cell fate decisions during development and cellular reprogramming. In addition to their well‐established role in chromatin opening to activate gene expression programs, recent studies have demonstrated that pioneer factors have the complementary function of being able to silence the starting cell identity through targeted chromatin repression. Given recent discoveries regarding the repressive aspect of pioneer function, we discuss the basis by which pioneer factors can suppress alternative lineage programs in the context of cell fate control. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are post‐transcriptional gene regulators. In the miRNA pathway's cytoplasmic part, the miRNA is processed from a hairpin‐structured precursor to a double‐stranded (ds) mature RNA and ultimately to a single‐stranded mature miRNA. In insects, ingesting these two ds forms can regulate the target gene expression; this inspired the trophic miRNA's use as a functional genomics and pest management tool. However, systematic studies enabling comparisons of pre‐ and mature forms, dosages, administration times and instar‐wise effects on target transcripts and phenotypes, which can help develop a miRNA administration method, are unavailable due to the different focuses of the previous investigations. We investigated the impact of trophically delivered Px‐let‐7 miRNA on the lepidopteran pest Plutella xylostella, to compare the efficacies of its pre‐ and ds‐mature forms. Continuous feeding on the miRNA‐supplemented diet suppressed expressions of FTZ‐F1 and E74, the target ecdysone pathway genes. Both the pre‐let‐7 and mature let‐7 miRNA forms similarly downregulated the target transcripts in all four larval instars. Pre‐let‐7 and let‐7 ingestions decreased larval mass and instar duration and increased mortality in all instars, exhibiting adverse effects on larval growth and development. miRNA processing Dicer‐1 and AGO‐1's upregulations upon miRNA ingestion denoted the systemic miRNA spread in larval tissues. The scrambled sequence controls did not affect the target transcripts, suggesting the sequence‐specific targeting by the mature miRNA and hairpin cassette's non‐involvement in the target downregulation. This work provides a framework for miRNA and target gene function analyses and potentiates the trophic miRNA's utility in pest management. [ABSTRACT FROM AUTHOR]

Photochemical internalization is an efficient strategy relying on photodynamic reactions to promote siRNA endosomal escape for the success of RNA‐interference gene regulation, which makes gene‐photodynamic combined therapy highly synergistic and efficient. However, it is still desired to explore capable carriers to improve the delivery efficiency of the immiscible siRNA and organic photosensitizers simultaneously. Herein, we employ a micellar nanostructure (PSNA) self‐assembled from polymer‐DNA molecular chimeras to fulfill this task. PSNA can plentifully load photosensitizers in its hydrophobic core simply by the nanoprecipitation method. Moreover, it can organize siRNA self‐assembly by the densely packed DNA shell, which leads to a higher loading capacity than the typical electrostatic condensation method. The experimental results prove that this PSNA carrier can greatly facilitate siRNA escape from the endosome/lysosome and enhance transfection. Accordingly, the PSNA‐administrated therapy exhibits a significantly improved anti‐tumor efficacy owing to the highly efficient co‐delivery capability. [ABSTRACT FROM AUTHOR]

Despite the array of mammalian transgene switches available for regulating therapeutic protein expression in response to small molecules or physical stimuli, issues remain, including cytotoxicity of chemical inducers and limited biocompatibility of physical cues. This study introduces gene switches driven by short peptides comprising eight or fewer amino acid residues. Utilizing a competence regulator (ComR) and sigma factor X‐inducing peptide (XIP) from Streptococcus vestibularis as the receptor and inducer, respectively, this study develops two strategies for a peptide‐activated transgene control system. The first strategy involves fusing ComR with a transactivation domain and utilizes ComR‐dependent synthetic promoters to drive expression of the gene‐of‐interest, activated by XIP, thereby confirming its membrane penetrability and intracellular functionality. The second strategy features an orthogonal synthetic receptor exposing ComR extracellularly (ComREXTRA), greatly increasing sensitivity with exceptional responsiveness to short peptides. In a proof‐of‐concept study, peptides are administered to type‐1 diabetic mice with microencapsulated engineered human cells expressing ComREXTRA for control of insulin expression, restoring normoglycemia. It is envisioned that this system will encourage the development of short peptide drugs and promote the introduction of non‐toxic, orthogonal, and highly biocompatible personalized biopharmaceuticals for gene‐ and cell‐based therapies. [ABSTRACT FROM AUTHOR]