Explore the vast range of titles available.

Plants often live in adverse environmental conditions and are exposed to various stresses, such as heat, cold, heavy metals, salt, radiation, poor lighting, nutrient deficiency, drought, or flooding. To adapt to unfavorable environments, plants have evolved specialized molecular mechanisms that serve to balance the trade-off between abiotic stress responses and growth. These mechanisms enable plants to continue to develop and reproduce even under adverse conditions. Ethylene, as a key growth regulator, is leveraged by plants to mitigate the negative effects of some of these stresses on plant development and growth. By cooperating with other hormones, such as jasmonic acid (JA), abscisic acid (ABA), brassinosteroids (BR), auxin, gibberellic acid (GA), salicylic acid (SA), and cytokinin (CK), ethylene triggers defense and survival mechanisms thereby coordinating plant growth and development in response to abiotic stresses. This review describes the crosstalk between ethylene and other plant hormones in tipping the balance between plant growth and abiotic stress responses.

Understanding how to engineer transcriptional regulation in plants is key to advancing both fundamental knowledge and practical applications in plant biology. Native gene promoters, while widely used, are constrained by evolutionary pressures that limit their modularity, tunability, and predictability across genetic backgrounds and species. Synthetic promoters, artificial DNA sequences composed of defined cis-regulatory elements (CREs) for recruitment of gene-specific transcription factors (TFs) and general transcriptional machinery, provide a powerful alternative for achieving fine-tuned transcriptional control. This review examines the design and application of synthetic promoters in plants, emphasizing current strategies, ongoing challenges, and avenues for innovation. We cover the structure of plant promoter architecture, including the contributions of core, proximal, and distal regions, and highlight how promoter grammar (i.e., motif identity, motif distance from transcription start site, spacing between motifs, helical phase of TF binding, motif orientation, and combinatorial interactions between motifs) impacts transcriptional activity. We outline how synthetic promoters are designed and validated via high-throughput reporter assays. Applications of synthetic promoters are discussed across functional genomics studies, biosensor creation, logic gate-based genetic circuits, and practical crop engineering, with examples covering constitutively expressing, hormone-responsive, pathogen-inducible, and abiotic stress-responsive promoter designs. We discuss traditional and emerging computational frameworks that enable CRE identification, novel synthetic promoter generation, and prediction of promoter sequence activity in silico to inform the rational design of promoters with predictable performance and spatiotemporal expression. We emphasize the importance of integrating experimental studies and computational approaches through iterative Design-Build-Test-Learn (DBTL) cycles to standardize and optimize frameworks for synthetic promoter development. By combining insights from plant promoter studies with advances in both plant-specific and non-plant synthetic promoter generation and computational modeling, researchers can expand synthetic promoter libraries to enable complex man-driven transcriptional regulation across various plant systems.

The horizontal transfer of mtDNA and its role in mediating resistance to therapy and an exit from dormancy have never been investigated. Here we identified the full mitochondrial genome in circulating extracellular vesicles (EVs) from patients with hormonal therapy-resistant (HTR) metastatic breast cancer. We generated xenograft models of HTR metastatic disease characterized by EVs in the peripheral circulation containing mtDNA. Moreover, these human HTR cells had acquired host-derived (murine) mtDNA promoting estrogen receptor-independent oxidative phosphorylation (OXPHOS). Functional studies identified cancer-associated fibroblast (CAF)-derived EVs (from patients and xenograft models) laden with whole genomic mtDNA as amediator of this phenotype. Specifically, the treatment of hormone therapy (HT)-naive cells or HT-treated metabolically dormant populations with CAF-derived mtDNAhi EVs promoted an escape from metabolic quiescence and HTR disease both in vitro and in vivo. Moreover, this phenotype was associated with the acquisition of EV mtDNA, especially in cancer stem-like cells, expression of EV mtRNA, and restoration of OXPHOS. In summary, we have demonstrated that the horizontal transfer of mtDNA from EVs acts as an oncogenic signal promoting an exit from dormancy of therapy-induced cancer stem-like cells and leading to endocrine therapy resistance in OXPHOS-dependent breast cancer.

The effects of auxins on plant growth and development have been known for more than 100 years, yet our understanding of how plants synthesize this essential plant hormone is still fragmentary at best. Gene loss-and gain-of-function studies have conclusively implicated three gene families, CYTOCHROME P450 79B2/B3 [CYP79B2/B3), YUCCA [YUC), and TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1/TRYPTOPHAN AMINOTRANSFERASE-RELATED (TAA1/TAR), in the production of this hormone in the reference plant Arabidopsis thaliana. Each of these three gene families is believed to represent independent routes of auxin biosynthesis. Using a combination of pharmacological, genetic, and biochemical approaches, we examined the possible relationships between the auxin biosynthetic pathways defined by these three gene families. Our findings clearly indicate that TAAI/TARs and YUCs function in a common linear biosynthetic pathway that is genetically distinct from the CYP79B2/B3 route. In the redefined TAA1-YUC auxin biosynthetic pathway, TAA1/TARs are required for the production of indole-3-pyruvic acid (IPyA) from Trp, whereas YUCs are likely to function downstream. These results, together with the extensive genetic analysis of four pyruvate decarboxylases, the putative downstream components of the TAA1 pathway, strongly suggest that the enzymatic reactions involved in indole-3-acetic acid (IAA) production via IPyA are different than those previously postulated, and a new and testable model for how IAA is produced in plants is needed.

Summary DNA assembly systems based on the Golden Gate method are popular in synthetic biology but have several limitations: small insert size, incompatibility with other cloning platforms, DNA domestication requirement, generation of fusion scars, and lack of post‐assembly modification. To address these obstacles, we present the DASH assembly toolset, which combines features of Golden Gate‐based cloning, recombineering, and site‐specific recombinase systems. We developed (1) a set of donor vectors based on the GoldenBraid platform, (2) an acceptor vector derived from the plant transformation‐competent artificial chromosome (TAC) vector, pYLTAC17, and (3) a re‐engineered recombineering‐ready E. coli strain, CZ105, based on SW105. The initial assembly steps are carried out using the donor vectors following standard GoldenBraid assembly procedures. Importantly, existing parts and transcriptional units created using compatible Golden Gate‐based systems can be transferred to the DASH donor vectors using standard single‐tube restriction/ligation reactions. The cargo DNA from a DASH donor vector is then efficiently transferred in vivo in E. coli into the acceptor vector by the sequential action of a rhamnose‐inducible phage‐derived PhiC31 integrase and arabinose‐inducible yeast‐derived Flippase (FLP) recombinase using CZ105. Furthermore, recombineering‐based post‐assembly modification, including the removal of undesirable scars, is greatly simplified. To demonstrate the utility of the DASH system, a 116 kilobase (kb) DNA construct harbouring a 97 kb cargo consisting of 35 transcriptional units was generated. One of the coding DNA sequences (CDSs) in the final assembly was replaced through recombineering, and the in planta functionality of the entire construct was tested in both transient and stable transformants.

Hormones play a central role in the coordination of internal developmental processes with environmental signals. Herein, a combination of physiological, genetic, cellular, and whole-genome expression profiling approaches has been employed to investigate the mechanisms of interaction between two key plant hormones: ethylene and auxin. Quantification of the morphological effects of ethylene and auxin in a variety of mutant backgrounds indicates that auxin biosynthesis, transport, signaling, and response are required for the ethylene-induced growth inhibition in roots but not in hypocotyls of dark-grown seedlings. Analysis of the activation of early auxin and ethylene responses at the cellular level, as well as of global changes in gene expression in the wild type versus auxin and ethylene mutants, suggests a simple mechanistic model for the interaction between these two hormones in roots, according to which ethylene and auxin can reciprocally regulate each other's biosyntheses, influence each other's response pathways, and/or act independently on the same target genes. This model not only implies existence of several levels of interaction but also provides a likely explanation for the strong ethylene response defects observed in auxin mutants.

A timely detection of patients with tetrahydrobiopterin (BH 4 ) -deficient types of hyperphenylalaninemia (HPABH 4 ) is important for assignment of correct therapy, allowing to avoid complications. Often HPABH 4 patients receive the same therapy as phenylalanine hydroxylase (PAH) -deficiency (phenylketonuria) patients—dietary treatment—and do not receive substitutive BH 4 therapy until the diagnosis is confirmed by molecular genetic means. In this study, we present a cohort of 30 Russian patients with HPABH 4 with detected variants in genes causing different types of HPA. Family diagnostics and biochemical urinary pterin spectrum analyses were carried out. HPABH 4 A is shown to be the prevalent type, 83.3% of all HPABH 4 cases. The mutation spectrum for the PTS gene was defined, the most common variants in Russia were p.Thr106Met—32%, p.Asn72Lys—20%, p.Arg9His—8%, p.Ser32Gly—6%. We also detected 7 novel PTS variants and 3 novel QDPR variants. HPABH 4 prevalence was estimated to be 0.5–0.9% of all HPA cases in Russia, which is significantly lower than in European countries on average, China, and Saudi Arabia. The results of this research show the necessity of introducing differential diagnostics for HPABH 4 into neonatal screening practice.

Abstract NFU1 is a mitochondrial protein that is involved in the biosynthesis of iron-sulfur clusters, and its genetic modification is associated with disorders of mitochondrial energy metabolism. Patients with autosomal-recessive inheritance of the NFU1 mutation G208C have reduced activity of the respiratory chain Complex II and decreased levels of lipoic-acid–dependent enzymes, and develop pulmonary arterial hypertension (PAH) in ∼70% of cases. We investigated whether rats with a human mutation in NFU1 are also predisposed to PAH development. A point mutation in rat NFU1G206C (human G208C) was introduced through CRISPR/Cas9 genome editing. Hemodynamic data, tissue samples, and fresh mitochondria were collected and analyzed. NFU1G206C rats showed increased right ventricular pressure, right ventricular hypertrophy, and high levels of pulmonary artery remodeling. Computed tomography and angiography of the pulmonary vasculature indicated severe angioobliterative changes in NFU1G206C rats. Importantly, the penetrance of the PAH phenotype was found to be more prevalent in females than in males, replicating the established sex difference among patients with PAH. Male and female homozygote rats exhibited decreased expression and activity of mitochondrial Complex II, and markedly decreased pyruvate dehydrogenase activity and lipoate binding. The limited development of PAH in males correlated with the preserved levels of oligomeric NFU1, increased expression of ISCU (an alternative branch of the iron-sulfur assembly system), and increased complex IV activity. Thus, the male sex has additional plasticity to overcome the iron-sulfur cluster deficiency. Our work describes a novel, humanized rat model of NFU1 deficiency that showed mitochondrial dysfunction similar to that observed in patients and developed PAH with the same sex dimorphism.