Background And Aims: The transformation of sieve elements (SEs) from meristematic cells, equipped with a full complement of organelles, to specialized transport tubes devoid of a nucleus, has long been enigmatic. We hypothesized a strong involvement of various degradation pathways, particularly macroautophagy in this context, emphasizing the importance of autophagic selectivity in the remaining viability of these cells.
Methods: Experiments were performed on pioneer roots of Populus trichocarpa cultivated in rhizotrons under field conditions.
Langerhans cell histiocytosis (LCH) is a histiocytic disorder that predominantly affects young children, with congenital manifestations being exceedingly rare. Here, we report a male infant with congenital LCH harboring a driving mutation within the mitogen-activated protein kinase pathway, specifically MAP2K1 Q56P. First-line use of targeted therapy with oral MEK inhibitor trametinib led to rapid and complete resolution of the infant's widespread cutaneous disease.
View Article and Find Full Text PDFBackground And Aims: The formation of multifunctional vascular tissues represents a significant advancement in plant evolution. Differentiation of conductive cells is specific, involving two main pathways, namely protoplast clearance and cell wall modification. In xylogenesis, autophagy is a crucial process for complete protoplast elimination in tracheary elements, whose cell wall also undergoes strong changes.
View Article and Find Full Text PDFThe evolution of plants to efficiently transport water and assimilates over long distances is a major evolutionary success that facilitated their growth and colonization of land. Vascular tissues, namely xylem and phloem, are characterized by high specialization, cell heterogeneity, and diverse cell components. During differentiation and maturation, these tissues undergo an irreversible sequence of events, leading to complete protoplast degradation in xylem or partial degradation in phloem, enabling their undisturbed conductive function.
View Article and Find Full Text PDFNorway maple and sycamore, two Acer genus species, have an important ecological value and different sensitivity to stressing factors being currently aggravated by climate change. Seedling growth is postulated to be the main barrier for successful plant establishment under the climate change scenarios. Therefore, the differences in redox regulation during the seedling performance of Norway maple and sycamore were investigated.
View Article and Find Full Text PDFPurpose: Germline missense variants of unknown significance in cancer-related genes are increasingly being identified with the expanding use of next-generation sequencing. The ataxia telangiectasia-mutated () gene on chromosome 11 has more than 1,000 germline missense variants of unknown significance and is a tumor suppressor. We aimed to determine if rare germline variants are more frequent in chronic lymphocytic leukemia (CLL) compared with other hematologic malignancies and if they influence the clinical characteristics of CLL.
View Article and Find Full Text PDFEuropean beech is an important component of European lowland forests in terms of ecology, and produces irregular seeds categorized as intermediate due to their limited longevity. Removal of the excess of reactive oxygen species is crucial for redox homeostasis in growing plant tissues. Hydrogen peroxide (HO) is detoxified via the plant-specific ascorbate-glutathione cycle, and enzymatically, mainly by catalase (CAT).
View Article and Find Full Text PDFMyelodysplastic syndromes (MDS) are clonal neoplasms of the hematopoietic stem cell that result in aberrant differentiation of hematopoietic lineages caused by a wide range of underlying genetic, epigenetic, and other causes. Despite the myriad origins, a recognizable MDS phenotype has been associated with miRNA aberrant expression. A model of aberrant myeloid maturation that mimics MDS was generated using a stable knockdown of miR-378-3p.
View Article and Find Full Text PDFAutophagy is a key but undervalued process in root ontogeny, ensuring both the proper development of root tissues as well as the senescence of the entire organ. Autophagy is a process which occurs during plant adaptation to changing environmental conditions as well as during plant ontogeny. Autophagy is also engaged in plant root development, however, the limitations of belowground studies make it challenging to understand the entirety of the developmental processes.
View Article and Find Full Text PDFSeed germination is a complex process enabling plant reproduction. Germination was found to be regulated at the proteome, metabolome and hormonal levels as well as via discrete post-translational modification of proteins including phosphorylation and carbonylation. Redox balance is also involved but less studied.
View Article and Find Full Text PDFBeech seeds are produced irregularly, and there is a need for long-term storage of these seeds for forest management practices. Accumulated reactive oxygen species broadly oxidize molecules, including amino acids, such as methionine, thereby contributing to decreased seed viability. Methionine oxidation can be reversed by the activity of methionine sulfoxide reductases (Msrs), which are enzymes involved in the regulation of many developmental processes and stress responses.
View Article and Find Full Text PDFTwo related tree species, Norway maple ( L.) and sycamore ( L.), produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively.
View Article and Find Full Text PDFThe levels of methionine sulfoxide (MetO) and the abundances of methionine sulfoxide reductases (Msrs) were reported as important for the desiccation tolerance of seeds. To determine whether the MetO/Msrs system is related to reactive oxygen species (ROS) and involved in the regulation of germination in orthodox and recalcitrant seeds, Norway maple and sycamore were investigated. Changes in water content, MetO content, the abundance of MsrB1 and MsrB2 in relation to ROS content and the activity of reductases depending on nicotinamide adenine dinucleotides were monitored.
View Article and Find Full Text PDFNorway maple and sycamore produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively. Drying affects reduction and oxidation (redox) status in seeds. Oxidation of methionine to methionine sulfoxide (MetO) and reduction via methionine sulfoxide reductases (Msrs) have never been investigated in relation to seed desiccation tolerance.
View Article and Find Full Text PDFDesiccation tolerance is a developmental program enabling seed survival in a dry state and is common in seeds categorized as orthodox. We focused on NAD and its phosphorylated form (NADP) because their continual switching between reduced (NAD(P)H) and oxidized (NAD(P)+) forms is involved in the modulation of redox signaling and the determination of the reducing power and further antioxidant responses. Norway maple and sycamore seeds representing the orthodox and recalcitrant categories, respectively, were used as models in a comparison of responses to water loss.
View Article and Find Full Text PDFPlant senescence is a highly regulated process that allows nutrients to be mobilized from dying tissues to other organs. Despite that senescence has been extensively studied in leaves, the senescence of ephemeral organs located underground is still poorly understood, especially in the context of phytohormone engagement. The present study focused on filling this knowledge gap by examining the roles of abscisic acid (ABA) and jasmonate in the regulation of senescence of fine, absorptive roots and leaves of Immunohistochemical (IHC), chromatographic, and molecular methods were utilized to achieve this objective.
View Article and Find Full Text PDFIn contrast to aboveground organs (stems and leaves), developmental events and their regulation in underground organs, such as pioneer and fine roots, are quite poorly understood. The objective of the current study was to achieve a better understanding of the physiological and molecular role of reactive oxygen species (ROS) and ROS-related enzymes in the process of stem and pioneer root development in black cottonwood (), as well as in the senescence of leaves and fine roots. Results of a transcriptomic analysis revealed that primary/secondary growth and senescence are accompanied by substantial changes in the expression of genes related to oxidative stress metabolism.
View Article and Find Full Text PDFThe remobilization and resorption of plant nutrients is considered as a crucial aspect of the seasonal senescence of plant organs. In leaves, the mechanisms responsible for the relocation of valuable compounds are well understood while the related processes in roots are still being debated. Some research indicates that remobilization in roots occurs, while other studies have not found evidence of this process.
View Article and Find Full Text PDFRegulation of gene expression, as determined by the genetics of the tree species, is a major factor in determining wood quality. Therefore, the identification of genes that play a role in xylogenesis is extremely important for understanding the mechanisms shaping the plant phenotype. Efforts to develop new varieties characterized by higher yield and better wood quality will greatly benefit from recognizing and understanding the complex transcriptional network underlying wood development.
View Article and Find Full Text PDFAutophagy is involved in developmentally programmed cell death and is identified during the early development of phloem, as well as xylem with a dual role, as both an inducer and executioner of cell death. The regulation of primary and secondary development of roots and stems is important for the establishment of root systems and for the overall survival of trees. The molecular and cellular basis of the autophagic processes, which are used at distinct moments during the growth of both organs, is crucial to understand the regulation of their development.
View Article and Find Full Text PDFBackground: Senescence, despite its destructive character, is a process that is precisely-regulated. The control of senescence is required to achieve remobilization of resources, a principle aspect of senescence. Remobilization allows plants to recapture valuable resources that would otherwise be lost to the environment with the senescing organ.
View Article and Find Full Text PDFSmall nuclear ribonucleoproteins (snRNPs) play a crucial role in pre-mRNA splicing in all eukaryotic cells. In contrast to the relatively broad knowledge on snRNP assembly within the nucleus, the spatial organization of the cytoplasmic stages of their maturation remains poorly understood. Nevertheless, sparse research indicates that, similar to the nuclear steps, the crucial processes of cytoplasmic snRNP assembly may also be strictly spatially regulated.
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