MID1-COMPLEMENTING ACTIVITY (MCA) is a land plant-specific, plasma membrane protein, and Ca2+ signaling component that responds to exogenous mechanical stimuli, such as touch, gravity, and hypotonic-osmotic stress, in various plant species. MCA is essential for cell proliferation and differentiation during growth and development in rice (Oryza sativa) and maize (Zea mays). However, the mechanism by which MCA mediates cell proliferation and differentiation via Ca2+ signaling remains unknown.
View Article and Find Full Text PDFChloroplasts accumulate on the cell surface under weak light conditions to efficiently capture light but avoid strong light to minimize photodamage. The blue light receptor phototropin regulates the chloroplast movement in various plant species. In Arabidopsis thaliana, phototropin mediates the light-induced chloroplast movement and positioning via specialized actin filaments on the chloroplasts, chloroplast-actin filaments.
View Article and Find Full Text PDFThe phenylpropanoid pathway is one of the plant metabolic pathways most prominently linked to the transition to terrestrial life, but its evolution and early functions remain elusive. Here, we show that activity of the t-cinnamic acid 4-hydroxylase (C4H), the first plant-specific step in the pathway, emerged concomitantly with the CYP73 gene family in a common ancestor of embryophytes. Through structural studies, we identify conserved CYP73 residues, including a crucial arginine, that have supported C4H activity since the early stages of its evolution.
View Article and Find Full Text PDFGametogenesis, which is essential to the sexual reproductive system, has drastically changed during plant evolution. Bryophytes, lycophytes and ferns develop reproductive organs called gametangia-antheridia and archegonia for sperm and egg production, respectively. However, the molecular mechanism of early gametangium development remains unclear.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2024
The miR390-derived TAS3 trans-acting short-interfering RNAs (tasiRNAs) module represents a conserved RNA silencing pathway in the plant kingdom; however, its characterization in the bryophyte Marchantia polymorpha is limited. This study elucidated that MpDCL4 processes MpTAS3 double-stranded RNA (dsRNA) to generate tasiRNAs, primarily from the 5'- and 3'-ends of dsRNA. Notably, we discovered a novel tasiRNA, tasi78A, which can negatively regulate a cytochrome P450 gene, MpCYP78A101.
View Article and Find Full Text PDFPlasma membrane H-ATPase provides the driving force for light-induced stomatal opening. However, the mechanisms underlying the regulation of its activity remain unclear. Here, we show that the phosphorylation of two Thr residues in the C-terminal autoinhibitory domain is crucial for H-ATPase activation and stomatal opening in Arabidopsis thaliana.
View Article and Find Full Text PDFA key adaptation of plants to life on land is the formation of water-conducting cells (WCCs) for efficient long-distance water transport. Based on morphological analyses it is thought that WCCs have evolved independently on multiple occasions. For example, WCCs have been lost in all but a few lineages of bryophytes but, strikingly, within the liverworts a derived group, the complex thalloids, has evolved a novel externalized water-conducting tissue composed of reinforced, hollow cells termed pegged rhizoids.
View Article and Find Full Text PDFIn land plants, gametes derive from a small number of dedicated haploid cells. In angiosperms, one central cell and one egg cell are differentiated in the embryo sac as female gametes for double fertilization, while in non-flowering plants, only one egg cell is generated in the female sexual organ, called the archegonium. The central cell specification of Arabidopsis thaliana is controlled by the histidine kinase CYTOKININ-INDEPENDENT 1 (CKI1), which is a two-component signaling (TCS) activator sharing downstream regulatory components with the cytokinin signaling pathway.
View Article and Find Full Text PDFSerine metabolism is involved in various biological processes. Here we investigate primary functions of the phosphorylated pathway of serine biosynthesis in a non-vascular plant Marchantia polymorpha by analyzing knockout mutants of MpPGDH encoding 3-phosphoglycerate dehydrogenase in this pathway. Growth phenotypes indicate that serine from the phosphorylated pathway in the dark is crucial for thallus growth.
View Article and Find Full Text PDFThermospermine suppresses auxin-inducible xylem differentiation, whereas its structural isomer, spermine, is involved in stress responses in angiosperms. The thermospermine synthase, ACAULIS5 (ACL5), is conserved from algae to land plants, but its physiological functions remain elusive in non-vascular plants. Here, we focused on MpACL5, a gene in the liverwort Marchantia polymorpha, that rescued the dwarf phenotype of the acl5 mutant in Arabidopsis.
View Article and Find Full Text PDFSexual differentiation is a fundamental process in the life cycles of land plants, ensuring successful sexual reproduction and thereby contributing to species diversity and survival. In the dioicous liverwort Marchantia polymorpha, this process is governed by an autosomal sex-differentiation locus comprising FEMALE GAMETOPHYTE MYB (FGMYB), a female-promoting gene, and SUPPRESSOR OF FEMINIZATION (SUF), an antisense strand-encoded long non-coding RNA (lncRNA). SUF is specifically transcribed in male plants and suppresses the expression of FGMYB, leading to male differentiation.
View Article and Find Full Text PDFThe plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism.
View Article and Find Full Text PDFCharacterizing phenotypes is a fundamental aspect of biological sciences, although it can be challenging due to various factors. For instance, the liverwort Marchantia polymorpha is a model system for plant biology and exhibits morphological variability, making it difficult to identify and quantify distinct phenotypic features using objective measures. To address this issue, we utilized a deep-learning-based image classifier that can handle plant images directly without manual extraction of phenotypic features and analyzed pictures of M.
View Article and Find Full Text PDFLand plants are a monophyletic group of photosynthetic eukaryotes that diverged from streptophyte algae about 470 million years ago. During both the alternating haploid and diploid stages of the life cycle, land plants form multicellular bodies. The haploid multicellular body (gametophyte) produces progenitor cells that give rise to gametes and the reproductive organs.
View Article and Find Full Text PDFPattern-recognition receptor (PRR)-triggered immunity (PTI) wards off a wide range of pathogenic microbes, playing a pivotal role in angiosperms. The model liverwort Marchantia polymorpha triggers defense-related gene expression upon sensing components of bacterial and fungal extracts, suggesting the existence of PTI in this plant model. However, the molecular components of the putative PTI in M.
View Article and Find Full Text PDFIn land plants, sexual dimorphism can develop in both diploid sporophytes and haploid gametophytes. While developmental processes of sexual dimorphism have been extensively studied in the sporophytic reproductive organs of model flowering plants such as stamens and carpels of Arabidopsis thaliana, those occurring in gametophyte generation are less well characterized due to the lack of amenable model systems. In this study, we performed three-dimensional morphological analyses of gametophytic sexual branch differentiation in the liverwort Marchantia polymorpha, using high-depth confocal imaging and a computational cell segmentation technique.
View Article and Find Full Text PDFThe evolution of special types of cells requires the acquisition of new gene regulatory networks controlled by transcription factors (TFs). In stomatous plants, a TF module formed by subfamilies Ia and IIIb basic helix-loop-helix TFs (Ia-IIIb bHLH) regulates stomatal formation; however, how this module evolved during land plant diversification remains unclear. Here we show that, in the astomatous liverwort Marchantia polymorpha, a Ia-IIIb bHLH module regulates the development of a unique sporophyte tissue, the seta, which is found in mosses and liverworts.
View Article and Find Full Text PDFAuxin plays pleiotropic roles in plant development via gene regulation upon its perception by the receptors TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFBs). This auxin-regulated transcriptional control mechanism originated in the common ancestor of land plants. Although the complete loss of TIR1/AFBs causes embryonic lethality in Arabidopsis thaliana, it is unclear whether the requirement for TIR1-mediated auxin perception in cell viability can be generalized.
View Article and Find Full Text PDFCytokinin, a plant hormone, plays essential roles in organ growth and development. The type-B response regulator-mediated cytokinin signaling is repressed by type-A response regulators and is conserved in the liverwort Marchantia polymorpha. Its signal coordinates the development of diverse organs on the thallus body, such as the gemma cup, rhizoid, and air pores.
View Article and Find Full Text PDFThe liverwort Marchantia polymorpha is equipped with a wide range of molecular and genetic tools and resources that have led to its wide use to explore the evo-devo aspects of land plants. Although its diverse transcriptome data are rapidly accumulating, there is no extensive yet user-friendly tool to exploit such a compilation of data and to summarize results with the latest annotations. Here, we have developed a web-based suite of tools, MarpolBase Expression (MBEX, https://marchantia.
View Article and Find Full Text PDFThe liverwort Marchantia polymorpha has been utilized as a model for biological studies since the 18th century. In the past few decades, there has been a Renaissance in its utilization in genomic and genetic approaches to investigating physiological, developmental, and evolutionary aspects of land plant biology. The reasons for its adoption are similar to those of other genetic models, e.
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