Formins are widely distributed in eukaryotes such as fungi, plants and animals. They play crucial roles in regulating the polymerization of actin, coordinating the synergistic interactions between actin and microtubules, and determining cell growth and morphology. Unlike formins from fungi and animals, plant formins have been evolved into two plant-specific types. Generally, type Ⅱ formins are believed to regulate the polarized growth of cells, and type Ⅰ formins may regulate the cell expansion and division processes. Recent studies on the function of plant formins suggest it is inappropriate to classify the function of formins purely based on their structures. This review summarizes the domain organization of formins and their corresponding functions, as well as the underpinning mechanisms. Furthermore, the unsolved or unexplored issues along with future perspectives on plant formins are proposed and discussed.
Actins ; Formins ; Microfilament Proteins ; Plant Cells ; Plant Development ; Plants

A comparison of plant and animal stem cells can highlight core aspects of stem-cell biology. In both kingdoms, stem cells are defined by their clonogenic properties and are maintained by intercellular signals. The signaling molecules are different in plants and animals stem cell niches, but the roles of argonaute and polycomb group proteins suggest that there are some molecular similarities.
Animals ; Plant Cells ; Signal Transduction ; Stem Cells ; cytology ; metabolism

Plant stem cells are the cells that are located in meristems and are kept in a state of undifferentiation. Plant stem cell possesses lower vacuolization, higher mitochondrial activity, more genetic stability and stronger self-renewal capacity compared with calli. Plant stem cell culture has a wide application in pharmaceutical, functional food as well as cosmetic industries. Here we describe the procedure of induction, isolation and identification of plant stem cells, to provide a reference for further research in this field.
Meristem ; cytology ; Plant Cells ; Stem Cells ; cytology ; Tissue Culture Techniques

Aquilaria sinensis callus induced by stem tips were used to establish the suspension cell system. The results showed that the most suitable medium for callus induction and subculture is MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA. After 12 times of subculture, the energetic and loose callus, which were appropriate for cell suspension culture, were cultured and shook in liquid medium MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA + 500.0 mg x L(-1) casein hydrolysate (CH) to establish the suspension cell system. The growth curve of suspension cells showed a "S" type. At the beginning of the culture, cell density increased slowly; during 4 to 6 days, suspension cells reached logarithmic growth period; during 7 to 12 days, suspension cells were in the platform period; but after 12 days, cell density and activity went down obviously. Agarwood sesquiterpenes were not detected in the suspension cells during the growth period, however, they could be detected in MeJA treated suspension cells. In this study, a stable and active growing suspension cell system was established, which was a proper system to study the mechanism of agarwood sesquiterpene formation, and additionally provided a potential way to generate agarwood sesquiterpenes through application of cell culture.
Cell Culture Techniques ; Plant Cells ; metabolism ; Plant Stems ; cytology ; Sesquiterpenes ; metabolism ; Thymelaeaceae ; cytology ; growth & development

Cell division and expansion require the ordered arrangement of microtubules, which are subject to spatial and temporal modifications by developmental and environmental factors. Understanding how signals translate to changes in cortical microtubule organization is of fundamental importance. A defining feature of the cortical microtubule array is its association with the plasma membrane; modules of the plasma membrane are thought to play important roles in the mediation of microtubule organization. In this review, we highlight advances in research on the regulation of cortical microtubule organization by membrane-associated and membrane-tethered proteins and lipids in response to phytohormones and stress. The transmembrane kinase receptor Rho-like guanosine triphosphatase, phospholipase D, phosphatidic acid, and phosphoinositides are discussed with a focus on their roles in microtubule organization.
Cell Membrane ; metabolism ; Environment ; Microtubules ; metabolism ; Plant Cells ; metabolism ; Plant Development ; Signal Transduction

Six new oligomeric neolignans including two trimeric neolignans (1 and 2) and four dimeric neolignans (3-6) were isolated from the leaves of Magnolia officinalis var. biloba. Their structures were determined based on HR-ESIMS and NMR data, as well as electronic circular dichroism (ECD) calculations. Compound 1 is formed from two obovatol moieties directly linked to an aromatic ring of the remaining obovatol moiety, which is an unprecedented type of linkage between monomers. All isolates were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 1 and 3 showed significantly inhibitory activities with IC
Animals ; Lignans/pharmacology* ; Magnolia/chemistry* ; Mice ; Molecular Structure ; Phytochemicals/pharmacology* ; Plant Extracts/pharmacology* ; Plant Leaves/chemistry* ; RAW 264.7 Cells

Agrobacterium tumefaciens induces cancerous growths called crown galls at wound sites on dicotyledonous plants. A large plasmid called T1 plasmid is responsible for virulence. Upon tumor induction, part of the plasmid, termed T-DNA, becomes integrated into plant genome and its genetic sequences are expressed. These properties allow T1 plasmids to be used as gene vectors in plants. Several in vitro methods for the transfer of T1 plasmid into plant cell have been developed. One of them is the treatment of bacterial spheroplasts and plant protoplasts mixture with polyethylene glycol that is generally used as fusogen in cell-to-cell fusion. Several workers investigated the interaction of bacterial spheroplasts with plant protoplasts in the presence of polyethylene glycol and suggested that the interaction is not fusion but endocytosis. In this report we observed the interaction of Agrobacterium tumefaciens spheroplasts with Nicotiana tabacum protoplasts by electron microscope. Agrobacterium tumefaciens spheroplasts with Nicotiana tabacum protoplasts were prepared and mixed in the presence of polyethylene glycol and high pH-high Ca²⁺ buffer. Then the interaction of the spheroplasts with the protoplasts was examined by transmission electron microscope. After the treatment of polyethylene glycol the spheroplasts adhered to the surface of the protoplasts and then they were engulfed by the protoplasts. After the high pH-high Ca²⁺ buffer treatment the engulfed spheroplasts lost their cell integrity. No fusion process was observed. Thus all these observation suggest that the introduction process of Agrobacterium tumefaciens spheroplasts into Nicotiana tabacum protoplasts with the aid of polyethylene glycol is endocytosis.
Agrobacterium tumefaciens* ; Agrobacterium* ; Endocytosis ; Genome, Plant ; In Vitro Techniques ; Plant Cells ; Plant Tumors ; Plants ; Plasmids ; Polyethylene Glycols ; Protoplasts* ; Spheroplasts* ; Tobacco* ; Virulence ; Wounds and Injuries

The endoplasmic reticulum quality control (ER-QC) is a conserved mechanism in surveillance of secreted signaling factors during cell-to-cell communication in eukaryotes. Recent data show that the ER-QC plays important roles in diverse cell-to-cell signaling processes during immune response, vegetative and reproductive development in plants. Pollen tube guidance is a precisely guided cell-cell communication process between the male and female gametophytes during plant reproduction. Recently, the female signal has been identified as small secreted peptides, but how the pollen tube responds to this signal is still unclear. In this review, we intend to summarize the role of ER-QC in plants and discuss the recent advances regarding our understanding of the mechanism of pollen tube response to the female signals.
Animals ; Endoplasmic Reticulum ; metabolism ; Humans ; Plant Cells ; metabolism ; Plant Development ; Plant Proteins ; genetics ; metabolism ; Plants ; immunology ; Pollen Tube ; cytology ; growth & development ; immunology ; metabolism ; Signal Transduction

The present study was designed to determine the chemical constituents of the stem tuber of Pinellia pedatisecta. The chemical constituents were isolated and purified by various chromatographic techniques, and their structures were elucidated on the basis of physicochemical properties and spectral data. Three new alkaloids (compounds 1, 2, and 3) were obtained and identified as 9-((5-methoxypyridin-2-yl)methyl)-9H-purin-6-amine (1), 4-(2-(2, 5-dioxopyrrolidin-1-yl)ethyl)phenyl acetate (2), and N-(9-((5-methoxypyridin-2-yl)methyl)-9H-purin-6-yl)acetamide (3). These compounds were evaluated for their cytotoxicity against human cervical cancer HeLa cells. Compounds 1 and 3 significantly inhibited the proliferation of HeLa cells with IC values being 3.02 ± 0.54 and 7.16 ± 0.62 μmol·L, respectively.
Alkaloids ; chemistry ; isolation & purification ; pharmacology ; Cell Proliferation ; drug effects ; HeLa Cells ; Humans ; Pinellia ; chemistry ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Plant Stems ; chemistry ; Plant Tubers ; chemistry

Ten compounds were isolated from the stems of Brucea mollis by various chromatographic techniques such as column chromatography on silica gel and Sephadex LH-20, and preparative HPLC, and their structures were elucidated as deacetylated isobrucein B (1), indaquassin X (2), cleomiscosin A (3), cleomiscosin B (4), (+)-lyoniresinol (5), (+)-epipinoresinol(6), (+)-pinoresinol (7), (+)-syringaresinol (8), 4,5-dihydroblumenol A (9) and adenosine (10) on the basis of spectroscopic data analysiS. All compounds were obtained from this plant for the first time, moreover, compound 1 was a new natural product. Compound 2 showed significant cytotoxic activities against the human cell lines HT-29, HepG2, BGC-823 and SKOV3 with IC50 values of 0.84-3.97 micromol x L(-1).
Brucea ; chemistry ; Cell Line, Tumor ; Drug Screening Assays, Antitumor ; HT29 Cells ; Hep G2 Cells ; Humans ; Inhibitory Concentration 50 ; Plant Extracts ; chemistry ; pharmacology ; Plant Stems ; chemistry ; Plants, Medicinal ; chemistry