Allelopathic influence of usnic acid on Physcomitrium patens: A proteomics approach.

Allelopathy, the chemical interaction of plants by their secondary metabolites with surrounding organisms, profoundly influences their functional features. Lichens, symbiotic associations of fungi and algae and/or cyanobacteria, produce diverse secondary metabolites, among other usnic acid, which express to have potent biological activities. Mosses, i.

CLE peptides act via the receptor-like kinase CRINKLY 4 in gametophore development.

The CLAVATA pathway plays a key role in the regulation of multicellular shoot and root meristems in flowering plants. In Arabidopsis, CLAVATA 3-like signaling peptides (CLEs) act via receptor-like kinases CLAVATA 1 and CRINKLY 4 (CR4). In the moss , PpCLAVATA and PpCR4 were previously studied independently and shown to play conserved roles in the regulation of cell proliferation and differentiation.

Regulation of developmental gatekeeping and cell fate transition by the calpain protease DEK1 in Physcomitrium patens.

Calpains are cysteine proteases that control cell fate transitions whose loss of function causes severe, pleiotropic phenotypes in eukaryotes. Although mainly considered as modulatory proteases, human calpain targets are directed to the N-end rule degradation pathway. Several such targets are transcription factors, hinting at a gene-regulatory role.

Membrane-anchored calpains - hidden regulators of growth and development beyond plants?

Calpains are modulatory proteases that modify diverse cellular substrates and play essential roles in eukaryots. The best studied are animal cytosolic calpains. Here, we focus on enigmatic membrane-anchored calpains, their structural and functional features as well as phylogenetic distribution.

The nuclear GUCT domain-containing DEAD-box RNA helicases govern gametophytic and sporophytic development in Physcomitrium patens.

Key Message: In RH1/RH2 are GUCT-domain-containing DEAD-BOX RNA helicases localize to the nucleus. They are implicated in cell and tissue development in all stages of the moss life cycle.

Abstract: The DEAD-box-containing RNA helicase family encompasses a large and functionally important group of enzymes involved in cellular processes committed to the metabolism of RNA, including its transcription, processing, transport, translation and decay.

A Study among the Genotype, Functional Alternations, and Phenotype of 9 SCN1A Mutations in Epilepsy Patients.

Mutations in the voltage-gated sodium channel Na1.1 (SCN1A) are linked to various epileptic phenotypes with different severities, however, the consequences of newly identified SCN1A variants on patient phenotype is uncertain so far. The functional impact of nine SCN1A variants, including five novel variants identified in this study, was studied using whole-cell patch-clamp recordings measurement of mutant Na1.

Challenges of protein localization in plants seen through the DEK1 protein lens.

During the last 25 y, fluorescent protein tagging has become a tool of choice to investigate protein function in a cellular context. The information gathered with this approach is not only providing insights into protein subcellular localization but also allows contextualizing protein function in multicellular settings. Here we illustrate the power of this method by commenting on the recent successful localization of the large membrane DEK1 protein during three-dimensional body formation in the moss .

Genome and Transcriptome Provide Insights into the Origin and Evolution of Streptophyta.

The Streptophyta include unicellular and multicellular charophyte green algae and land plants. Colonization of the terrestrial habitat by land plants is a major evolutionary event that has transformed the planet. So far, lack of genome information on unicellular charophyte algae hinders the understanding of the origin and the evolution from unicellular to multicellular life in Streptophyta.

DEK1 displays a strong subcellular polarity during Physcomitrella patens 3D growth.

Defective Kernel 1 (DEK1) is genetically at the nexus of the 3D morphogenesis of land plants. We aimed to localize DEK1 in the moss Physcomitrella patens to decipher its function during this process. To detect DEK1 in vivo, we inserted the tdTomato fluorophore into PpDEK1 gene locus.

An intragenic mutagenesis strategy in Physcomitrella patens to preserve intron splicing.

Gene targeting is a powerful reverse genetics technique for site-specific genome modification. Intrinsic homologous recombination in the moss Physcomitrella patens permits highly effective gene targeting, a characteristic that makes this organism a valuable model for functional genetics. Functional characterization of domains located within a multi-domain protein depends on the ability to generate mutants harboring genetic modifications at internal gene positions while maintaining the reading-frames of the flanking exons.

The DEK1 Calpain Linker Functions in Three-Dimensional Body Patterning in Physcomitrella patens.

The DEFECTIVE KERNEL1 (DEK1) calpain is a conserved 240-kD key regulator of three-dimensional body patterning in land plants acting via mitotic cell plane positioning. The activity of the cytosolic C-terminal calpain protease is regulated by the membrane-anchored DEK1 MEM, which is connected to the calpain via the 600-amino acid residue Linker. Similar to the calpain and MEM domains, the Linker is highly conserved in the land plant lineage, the similarity dropping sharply compared with orthologous charophyte sequences.

The phenotype of the CRINKLY4 deletion mutant of Physcomitrella patens suggests a broad role in developmental regulation in early land plants.

Deletion of the ancestral gene of the land plant multigene family of receptor like kinase CR4 in Physcomitrella patens demonstrates involvement in developmental control of gametophytic and sporophytic organs. The CRINKLY4 (CR4) family of receptor kinases in angiosperms consists of three clades, one including CR4, the CR4-related CCR1 and CCR2, a second including CCR3 and CCR4 family members, and a third and more distant clade. In addition to crinkly leaves in maize, which gave rise to the mutant gene name, CR4 is implicated in ovule, embryo, flower and root development in Arabidopsis thaliana.

DEK1; missing piece in puzzle of plant development.

Patterning of land plant bodies is determined by positioning of cell walls. A crucial event in land plant evolution was the ability to utilize spatial information to direct cell wall deposition. Recent studies of DEK1 in Physcomitrella patens support a role for DEK1 in position dependent cell wall orientation.

Defective Kernel 1 (DEK1) is required for three-dimensional growth in Physcomitrella patens.

Orientation of cell division is critical for plant morphogenesis. This is evident in the formation and function of meristems and for morphogenetic transitions. Mosses undergo such transitions: from two-dimensional tip-growing filaments (protonema) to the generation of three-dimensional leaf-like structures (gametophores).

The catalytic domain CysPc of the DEK1 calpain is functionally conserved in land plants.

DEK1, the single calpain of land plants, is a member of the ancient membrane bound TML-CysPc-C2L calpain family that dates back 1.5 billion years. Here we show that the CysPc-C2L domains of land plant calpains form a separate sub-clade in the DEK1 clade of the phylogenetic tree of plants.

Massive expansion of the calpain gene family in unicellular eukaryotes.

Background: Calpains are Ca2+-dependent cysteine proteases that participate in a range of crucial cellular processes. Dysfunction of these enzymes may cause, for instance, life-threatening diseases in humans, the loss of sex determination in nematodes and embryo lethality in plants. Although the calpain family is well characterized in animal and plant model organisms, there is a great lack of knowledge about these genes in unicellular eukaryote species (i.

Gabaculine alters plastid development and differentially affects abundance of plastid-encoded DPOR and nuclear-encoded GluTR and FLU-like proteins in spruce cotyledons.

Synthesis of 5-aminolevulinic acid (ALA) represents a rate limiting step in the tetrapyrrole biosynthetic pathway, and is regulated by metabolic feedback control of glutamyl-tRNA reductase (GluTR) activity. The FLU protein has been attributed to this regulation. Later in the biosynthetic pathway, reduction of protochlorophyllide (Pchlide), catalyzed by protochlorophyllide oxidoreductase (POR), ensures another important regulatory step in the chlorophyll biosynthesis.

Trap closure and prey retention in Venus flytrap (Dionaea muscipula) temporarily reduces photosynthesis and stimulates respiration.

Background And Aims: The carnivorous plant Venus flytrap (Dionaea muscipula) produces a rosette of leaves: each leaf is divided into a lower part called the lamina and an upper part, the trap, with sensory trigger hairs on the adaxial surface. The trap catches prey by very rapid closure, within a fraction of a second of the trigger hairs being touched twice. Generation of action potentials plays an important role in closure.

Feeding enhances photosynthetic efficiency in the carnivorous pitcher plant Nepenthes talangensis.

Background And Aims: Cost-benefit models predict that carnivory can increase the rate of photosynthesis (A(N)) by leaves of carnivorous plants as a result of increased nitrogen absorption from prey. However, the cost of carnivory includes decreased A(N) and increased respiration rates (R(D)) of trapping organs. The principal aim of the present study was to assess the costs and benefits of carnivory in the pitcher plant Nepenthes talangensis, leaves of which are composed of a lamina and a pitcher trap, in response to feeding with beetle larvae.

A novel insight into the regulation of light-independent chlorophyll biosynthesis in Larix decidua and Picea abies seedlings.

Light-independent chlorophyll (Chl) biosynthesis is a prerequisite for the assembly of photosynthetic pigment-protein complexes in the dark. Dark-grown Larix decidua Mill. seedlings synthesize Chl only in the early developmental stages and their Chl level rapidly declines during the subsequent development.