(L.) Rich, an endangered member of the Orchidaceae family, is found in alkaline fens. With the declining populations of , there is a pressing need to reintroduce this species in Central Europe.
View Article and Find Full Text PDFDespite the clear circumscription of tribe Sobralieae (Orchidaceae), its internal relationships are still dubious. The recently delimited genus , based on previous species, is now assumed to be paraphyletic, with a third genus, , nested in it. The morphology of these three genera is significantly different, indicating the necessity of new data for a better genera delimitation.
View Article and Find Full Text PDFThe special mixed reproductive system, i.e., the ability of an individual plant to develop both open, chasmogamous (CH) flowers adapted to cross-pollination and closed, cleistogamous (CL) flowers with obligate self-pollinating, is a common phenomenon in L.
View Article and Find Full Text PDFEukaryotic cells rely on the accuracy and efficiency of vesicular traffic. In plants, disturbances in vesicular trafficking are well studied in quickly dividing root meristem cells or polar growing root hairs and pollen tubes. The development of the female gametophyte, a unique haploid reproductive structure located in the ovule, has received far less attention in studies of vesicular transport.
View Article and Find Full Text PDFCyclotides are defense peptides produced by several plant families. Viola spp. (Violaceae) produce an array of cyclotides with varying biological activities.
View Article and Find Full Text PDFCyclotides are cyclic plant polypeptides of 27-37 amino acid residues. They have been extensively studied in bioengineering and drug development contexts. However, less is known about the relevance of cyclotides for the plants producing them.
View Article and Find Full Text PDFBackground And Aims: In the Brassicaceae family, apomictic development is characteristic of the genus Boechera. Hybridization, polyploidy and environmental adaptation that arose during the evolution of Boechera may serve as (epi)genetic regulators of apomictic initiation in this genus. Here we focus on Boechera stricta, a predominantly diploid species that reproduces sexually.
View Article and Find Full Text PDFThe development of different pollen morphs by one specimen - pollen heteromorphism - occurs in ca. one-third species of the genus Viola. Melanium section species (pansies) stand out in producing the widest range of apertures among Viola species.
View Article and Find Full Text PDFProtoplasma
March 2018
Two representatives of section Lepidorhiza, previously sometimes considered conspecific, Bulbophyllum levanae and Bulbophyllum nymphopolitanum, demonstrated both similarities and differences in floral features. There were significant differences in the length of sepals and micromorphological features of the labellum. In both species, osmophores are located on the extended apices of sepals and possibly on petals.
View Article and Find Full Text PDFThe distribution of cyclotides was visualized in plant cells, tissues and organs using immunohistochemistry. Finding of cyclotides in tissues potentially vulnerable to pathogen attacks supports their role as defense molecules. The cyclotide family of plant peptides is characterized by the cyclic cystine knot motif and its diverse biological activities.
View Article and Find Full Text PDFThe lip of Epipactis palustris consists of two movably joined parts: the basal part (hypochile) with central broad isthmus and epichile with callus. The analysis of flowers provides strong evidence to conclude that the whole surface of lip callus and abaxial side of isthmus are secretory. The exudation at first appears on callus, at early stages, later on isthmus.
View Article and Find Full Text PDFPaphiopedilum canhii was discovered in Northern Vietnam. Since its description in 2010, it has caused a stir among taxonomists due to its interesting mixture of morphological features, i.e.
View Article and Find Full Text PDFChalazal endosperm haustorium in Rhinanthus serotinus consists of a single large binucleate cell. It originates from the primary endosperm cell dividing transversely into two unequal cells: a smaller micropylar cell and a larger chalazal cell. The chalazal cell undergoes a single mitotic division, then lengthens significantly during development and functions as a chalazal endosperm haustorium.
View Article and Find Full Text PDFThe paper reports studies, including histological and ultrastructural analyses, of in vitro cell proliferation and development of immature endosperm tissue isolated from caryopses of Triticum aestivum, Triticum durum, and Triticosecale plants. Endosperm isolated at 7-10 days post-anthesis developed well on MS medium supplemented with auxins and/or cytokinins. The efficiency of endosperm response was highly genotype-dependent and best in two winter cultivars of hexaploid species.
View Article and Find Full Text PDFCutin fluorescence, after auramine O treatment, was detected on the surface of organogenic areas (protuberances) of endosperm derived callus induced on Murashige and Skoog medium with thidiazuron (0.5 mg l(-1)) in darkness. Electron micrographs of the protuberances revealed cuticle, visible as a dark-staining layer, and amorphous waxes on the cell wall.
View Article and Find Full Text PDFThe development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells.
View Article and Find Full Text PDFThe changes in the formation of both the actin and the microtubular cytoskeleton during the differentiation of the embryo-suspensor in Sedum acre were studied in comparison with the development of the embryo-proper. The presence and distribution of the cytoskeletal elements were examined ultrastructurally and with the light microscope using immunolabelling and rhodamine-phalloidin staining. At the globular stage of embryo development extensive array of actin filaments is present in the cytoplasm of basal cell, the microfilament bundles generally run parallel to the long axis of basal cell and pass in close to the nucleus.
View Article and Find Full Text PDFActinidia deliciosa endosperm-derived callus culture is stable over a long period of culture. This system was used to investigate the ultrastructure of extracellular matrix occurring in morphogenic tissue. Specimens were prepared by different biological techniques (chemical fixation, liquid nitrogen fixation, glycerol substitution, critical-point drying, lyophilization) and observed by scanning electron microscopy (SEM).
View Article and Find Full Text PDFPlasmodesmata ensure the continuity of cytoplasm between plant cells and play an important part in the intercellular communication and signal transduction. During the development of the suspensor of both Sedum acre L. and Sedum hispanicum L.
View Article and Find Full Text PDFStomachs of the Great Cormorant (Phalacrocorax carbo) from north-eastern Poland were found to contain adult nematode Contracaecum rudolphii [Hartwich, G., 1964. Revision der Vogelparasitischen Nematoden Mitteleuropas II.
View Article and Find Full Text PDFEndosperm is an interesting model for in vitro experiments, because of its unique origin, development and ploidy level. Here we used Actinidia deliciosa endosperm-derived callus to investigate morphology, histology and chemistry of extracellular matrix (ECM) structures in morphogenically stable tissue from long-term culture. SEM and TEM analysis showed that ECM is a heterogenous layer which consists of amorphous, dark-staining material, osmiophilic granules and reticulated fibres outside the outer callus cell wall.
View Article and Find Full Text PDFThe study used Actinidia deliciosa endosperm-derived callus to investigate aspects of the morphology, histology and chemistry of extracellular matrix (ECM) structures in morphogenically stable tissue from long-term culture. SEM showed ECM as a membranous layer or reticulated fibrillar and granular structure linking the peripheral cells of callus domains. TEM confirmed that ECM is a distinct heterogeneous layer, up to 4 mum thick and consisting of amorphous dark-staining material, osmiophilic granules and reticulated fibres present outside the outer callus cell wall.
View Article and Find Full Text PDFThe distribution of several arabinogalactan protein and pectic epitopes were studied during organogenesis in androgenic callus of wheat. In cell wall of mature and degenerating parenchyma cells, the arabinogalactan epitopes JIM4, JIM14, JIM16 or LM2 were expressed differently according to the cells location. LM2 was observed also in meristematic cells of regenerated shoot buds and leaves.
View Article and Find Full Text PDFMucopolysaccharidoses (MPS) are heritable, metabolic diseases caused by accumulation of mucopolysaccharides (glycosaminoglycans, GAGs) in lysosomes. This accumulation is due to a deficiency in one of several specific enzymes involved in the degradation of GAGs. MPS type I (MPS I) is caused by low or undetectable activity of alpha-L-iduronidase, an enzyme involved in removing the terminal iduronic acid residues from heparan and dermatan sulfate.
View Article and Find Full Text PDFThe smooth muscle cells (SMCs) of the arterial media play a predominant role in functional and structural alterations of the arterial wall. The transition from the "contractile" to the "synthetic" phenotype appears to be an early critical event in the development of atherosclerotic disease. A number of observations suggest that 1,25(OH)(2)D(3) (calcitriol) is of importance in maintaining normal cardiovascular function through its receptors in cardiac myocytes or aortal SMCs.
View Article and Find Full Text PDF