Rapid movements of plant structures triggered by mechanical force have been documented for centuries; however, how plant cells sense mechanical stimuli and generate rapid response remains unknown. Here we show the central role of a mechanosensitive channel gene in touch-triggered rapid stigma movement of Torenia fournieri. T.
View Article and Find Full Text PDFHormones play an essential role in the survival and maintenance of homeostasis. Steroid hormones are structurally and evolutionarily conserved across animals, insects, and plants. Brassinosteroids (BRs) are plant steroid hormones originally isolated from pollen grains.
View Article and Find Full Text PDFMitochondrial DNA (mtDNA) is organized with proteins into mitochondrial nucleoid (mt-nucleoid). The mt-nucleoid is a unit for the maintenance and function of mtDNA. The regulator of chromosome condensation 1-like protein (RCC1L) performs various functions in mitochondria, including translation, but its involvement in regulating mt-nucleoid maintenance is unknown.
View Article and Find Full Text PDFSeed formation is essential for plant propagation and food production. We present a novel mechanism for the regulation of seed size by a newly identified "gate" at the chalazal end of the ovule regulating nutrient transport into the developing seed. This gate is blocked by callose deposition in unfertilized mature ovules (closed state), but the callose is removed after central cell fertilization, allowing nutrient transport into the seed (open state).
View Article and Find Full Text PDFIn flowering plants, pollen tube growth is essential for delivering immotile sperm cells during double fertilization, directly influencing seed yield. This process relies on vesicle-mediated trafficking to sustain tip growth and fertility. However, investigating pollen tube growth is challenging in non-model plants due to the lack of transgenic tools.
View Article and Find Full Text PDFProc Jpn Acad Ser B Phys Biol Sci
April 2025
Cell proliferation is a fundamental characteristic of organisms, driven by the holistic functions of multiple proteins encoded in the genome. However, the individual contributions of thousands of genes and the millions of protein molecules they express to cell proliferation are still not fully understood, even in simple eukaryotes. Here, we present a genome-wide translation map of cells during proliferation in the unicellular alga Cyanidioschyzon merolae, based on the sequencing of ribosome-protected messenger RNA fragments.
View Article and Find Full Text PDFUpon fertilization, male and female nuclei fuse to form the zygotic nucleus in angiosperms. Karyogamy is considered to be essential for proper embryogenesis; however, the transcriptional dynamics during karyogamy in plant zygotes remain unclear. In this study, we performed a single-cell transcriptome analysis of rice zygotes at six early developmental stages (15 min, 30 min, 1 h, 2 h, 4 h, and 6 h after gamete fusion) to reveal gene expression profiles during karyogamy in plant zygotes.
View Article and Find Full Text PDFPlants develop along apical-basal and radial axes. In Arabidopsis thaliana, the radial axis becomes evident when the cells of the 8-cell proembryo divide periclinally, forming inner and outer cell layers. Although changes in cell polarity or morphology likely precede this oriented cell division, the initial events and the factors regulating radial axis formation remain elusive.
View Article and Find Full Text PDFBackground: In Angiosperms, the continuation of plant species is intricately dependent on the funiculus multifaceted role in nutrient transport, mechanical support, and dehiscence of seeds. SEEDSTICK (STK) is a MADS-box transcription factor involved in seed size and abscission, and one of the few genes identified as affecting funiculus growth. Given the importance of the funiculus to a correct seed development, allied with previous phenotypic observations of stk mutants, we performed a transcriptomic analysis of stk funiculi from floral stage 17, using RNA-sequencing, to infer on the deregulated networks of genes.
View Article and Find Full Text PDFArabinogalactan proteins (AGPs) are plant-specific glycoproteins involved in cellular mechanics and signal transduction. There has been major progress in understanding the structure, synthesis, and molecular functions of their carbohydrate chains; however, the mechanisms by which they function as signalling molecules remain unclear. Here, methyl-glucuronosyl arabinogalactan (AMOR; Me-GlcA-β(1,6)-Gal), a disaccharide structure at the end of AGP carbohydrate chains, was oligomerised chemical synthesis.
View Article and Find Full Text PDFEukaryotic flagella collectively form metachronal waves that facilitate the ability to cause flow or swim. Among such flagellated and planktonic swimmers, large volvocine genera such as Eudorina, Pleodorina and Volvox form bundles of small male gametes (sperm) called "sperm packets" for sexual reproduction. Although these sperm packets reportedly have flagella and the ability to swim, previous studies on volvocine motility have focused on asexual forms and the swimming characteristics of sperm packets remain unknown.
View Article and Find Full Text PDFMitochondrial biogenesis relies on hundreds of proteins that are derived from genes encoded in the nucleus. According to the characteristic properties of N-terminal targeting peptides (TPs) and multi-step authentication by the protein translocase called the TOM complex, nascent polypeptides satisfying the requirements are imported into mitochondria. However, it is unknown whether eukaryotic cells with a single mitochondrion per cell have a similar complexity of presequence requirements for mitochondrial protein import compared to other eukaryotes with multiple mitochondria.
View Article and Find Full Text PDFIn the pistil of flowering plants, each ovule usually associates with a single pollen tube for fertilization. This one-to-one pollen tube guidance, which contributes to polyspermy blocking and efficient seed production, is largely different from animal chemotaxis of many sperms to one egg. However, the functional mechanisms underlying the directional cues and polytubey blocks in the depths of the pistil remain unknown.
View Article and Find Full Text PDFThe centromere is an essential chromosome region where the kinetochore is formed to control equal chromosome distribution during cell division. The centromere-specific histone H3 variant CENH3 (also called CENP-A) is a prerequisite for the kinetochore formation. Since CENH3 evolves rapidly, associated factors, including histone chaperones mediating the deposition of CENH3 on the centromere, are thought to act through species-specific amino acid sequences.
View Article and Find Full Text PDFPlants are exposed to a variety of environmental stress, and starvation of inorganic phosphorus can be a major constraint in crop production. In plants, in response to phosphate deficiency in soil, miR399, a type of microRNA (miRNA), is up-regulated. By detecting miR399, the early diagnosis of phosphorus deficiency stress in plants can be accomplished.
View Article and Find Full Text PDFPlasma membrane damage (PMD) occurs in all cell types due to environmental perturbation and cell-autonomous activities. However, cellular outcomes of PMD remain largely unknown except for recovery or death. In this study, using budding yeast and normal human fibroblasts, we found that cellular senescence-stable cell cycle arrest contributing to organismal aging-is the long-term outcome of PMD.
View Article and Find Full Text PDFMany terrestrial plants produce large quantities of alkanes for use in epicuticular wax and the pollen coat. However, their carbon chains must be long to be useful as fuel or as a petrochemical feedstock. Here, we focus on Nymphaea odorata, which produces relatively short alkanes in its anthers.
View Article and Find Full Text PDFThe gynoecium is critical for the reproduction of flowering plants as it contains the ovules and the tissues that foster pollen germination, growth, and guidance. These tissues, known as the reproductive tract (ReT), comprise the stigma, style, and transmitting tract (TT). The ReT and ovules originate from the carpel margin meristem (CMM) within the pistil.
View Article and Find Full Text PDFThe 33rd International Conference on Arabidopsis Research (ICAR2023) was held at Makuhari Messe International Conference Hall in Chiba prefecture from June 5 to 9, 2023. This annual conference, which rotates among hosts in North America, Asia-Oceania, and Europe, covers the full range of plant biology research involving Arabidopsis and other plant species. The conference hosted more than 1200 participants, including approximately 800 international attendees from 42 countries (or regions), and featured about 900 oral and poster presentations.
View Article and Find Full Text PDFThe three-dimensional shape of a flower is integrated by morphogenesis along different axes. Differentiation along the petal proximodistal axis is tightly linked to the specification of pollinators; however, it is still unclear how a petal patterns this axis. The corolla of Torenia fournieri exhibits strong differentiation along the proximodistal axis, and we previously found a proximal regulator, TfALOG3, controlling corolla neck differentiation.
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