Studies of the holoparasite Tristerix aphyllus (Loranthaceae) infecting Trichocereus chilensis (Cactaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 847-857 ◽  
Author(s):  
James D. Mauseth ◽  
Gloria Montenegro ◽  
Alan M. Walckowiak
Keyword(s):  
Cell Division ◽  
Host Cells ◽  
Vascular Cambium ◽  
Seed Plants ◽  
Tracheary Elements ◽  
Flower Buds ◽  
Flower Stalk ◽  
Columnar Cacti ◽  
Stems And Leaves ◽  
Longitudinal Cell

Many of the large columnar cacti Trichocereus chilensis near Santiago are infected by Tristerix aphyllus. This is one of the most highly reduced seed plants known: as it is an endoparasite, inflorescences are the only parts of the plant ever to emerge from the host, all the rest exists as an endophytic haustorial system; roots, vegetative stems, and leaves are not produced. After infection, the parasite spreads through the thick cortex of the host, reaching the vascular cambium and conducting tissues. It continues to grow intrusively throughout all tissues of the host shoot. In its invasive stage it occurs as a "myceliumlike" mass of uniseriate filaments that grow between host cells but only rarely enter them. Later growth is by longitudinal cell division that produces irregular parenchymatous strands. Eventually, xylem and phloem differentiate in the endophytic strands; the phloem is like that of other seed plants, but the xylem is almost pure parenchyma, with only occasional, idioblastic tracheary elements. Strands close to the epidermis of the host are able to produce adventitious flower buds that emerge through either soft regions in the epidermis (the areoles) or through accidental breaks in it. The flower stalk may persist, forming a small perennial inflorescence that has well-developed xylem, phloem, and periderm but is without leaves. Host cells appear healthy and normal, with no sign of damage caused by the presence of the parasite.

scholarly journals SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Knockout Mutant ◽  
Content Type ◽  
Moonlighting Protein ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).

scholarly journals NOTES ON THE EGG AND YOUNG LARVA OF ALARIA FLORIDA

1871 ◽  
Vol 3 (4) ◽  
pp. 76-76 ◽  
Author(s):  
W. Saunders
Keyword(s):  
Young Larva ◽  
Flower Buds ◽  
Flower Stalk ◽  
Evening Primrose ◽  
Young Leaves

On the 4th of July I found a number of eggs of this beautiful moth on the evening primrose, Œnothera Lamarckiana. They were found attached to the stalks of the young flower buds; to the sides of the calyx of the flower, and also to the young leaves at their base. The eggs were quite firmly fastened among the long stout hairs with which the cuticle of the calyx and flower stalk is covered.

The cell cycle of symbiotic Chlorella. I. The relationship between host feeding and algal cell growth and division

1985 ◽  
Vol 77 (1) ◽  
pp. 225-239
Author(s):  
P.J. McAuley
Keyword(s):  
Cell Division ◽  
Cell Growth ◽  
Host Cell ◽  
Algal Cell ◽  
Host Cells ◽  
Digestive Cell ◽  
Host Feeding ◽  
Digestive Cells ◽  
Division Factor ◽  
Cell Mitosis

When green hydra were starved, cell division of the symbiotic algae within their digestive cells was inhibited, but algal cell growth, measured as increase in either mean volume or protein content per cell, was not. Therefore, control of algal division by the host digestive cells must be effected by direct inhibition of algal mitosis rather than by controlling algal cell growth. The number of algae per digestive cell increased slightly during starvation, eventually reaching a new stable level. A number of experiments demonstrated that although there was a relationship between host cell and algal mitosis, this was not causal: the apparent entrainment of algal mitosis to that of the host cells could be disrupted. Thus, there was a delay in algal but not host cell mitosis when hydra were fed after prolonged starvation, and algae repopulated starved hydra with lower than normal numbers of algae (reinfected aposymbionts or hydra transferred to light after growth in continuous darkness). Two experiments demonstrated a direct stimulation of algal cell division by host feeding. Relationships of algal and host cell mitosis to numbers of Artemia digested per hydra were different, and in hydra fed extracted Artemia algal, but not host cell, mitosis was reduced in comparison to that in control hydra fed live shrimp. It is proposed that algal division may be dependent on a division factor, derived from host digestion of prey, whose supply is controlled by the host cells. Numbers of algae per cell would be regulated by competition for division factor, except at host cell mitosis, when the algae may have temporarily uncontrolled access to host pools of division factor. The identity of the division factor is not known, but presumably is a metabolite needed by both host cells and algae.

The growth of apricot fruit. II. The effects of temperature and gibberellic acid

1967 ◽  
Vol 18 (1) ◽  
pp. 95 ◽  
Author(s):  
DI Jackson ◽  
BG Coombe
Keyword(s):  
Growth Rate ◽  
Cell Division ◽  
Gibberellic Acid ◽  
Fruit Size ◽  
Fruit Growth ◽  
Cell Diameter ◽  
Initial Growth ◽  
Endogenous Gibberellin ◽  
Flower Buds ◽  
Size And Shape

The effect of temperature and gibberellic acid (GA3) applications on apricot fruit have been determined by measurements of fruit size and shape, mesocarp cell number, size, and shape, and endogenous gibberellin. Application of heat during the first 10 nights after anthesis increased the initial growth rate of fruit and of cells in the mesocarp and produced more rapid cell division in this tissue. It did not affect final fruit size or the number and diameter of cells in the mesocarp. Higher temperatures did, however, hasten maturity of fruit. GA3 perfused into branches before anthesis produced an increased drop of flower buds and fruit, raised the ratio of flower buds to leaf buds initiated that season, and resulted in elongated pedicels. Initially, fruit growth rate was increased by GA3, but subsequently it was depressed and final size was below normal. These effects on fruit size were mainly due to effects on the rate of cell division. Some differences were noted in the dimensions of cells but final radial cell diameter did not differ from untreated fruit. GA3-treated fruit ripened sooner than controls. Neither heating nor GA3 treatments affected the level of endogenous gibberellin-like substances in the fruit or their RF on paper chromatograms. There were no significant interactions between temperature and gibberellin in any parameter of apricot fruit growth.

Ultrastructure of cell division in the fusiform cells of the vascular cambium of

Trees ◽  
1997 ◽  
Vol 11 (4) ◽  
pp. 203 ◽  
Author(s):  
J. J. Farrar ◽  
Ray F. Evert
Keyword(s):  
Cell Division ◽  
Vascular Cambium

scholarly journals Mycobacterial Di-O-Acyl-Trehalose Inhibits Mitogen- and Antigen-Induced Proliferation of Murine T Cells In Vitro

2001 ◽  
Vol 8 (6) ◽  
pp. 1081-1088 ◽  
Author(s):  
Rafael Saavedra ◽  
Erika Segura ◽  
Rosario Leyva ◽  
Luis A. Esparza ◽  
Luz M. López-Marı́n
Keyword(s):  
Cell Division ◽  
Cell Envelope ◽  
Inhibitory Effect ◽  
Host Cells ◽  
Mouse Spleen ◽  
Dependent Manner ◽  
Spleen Cells ◽  
Murine Spleen ◽  
Focus Of Infection

ABSTRACT 2,3-Di-O-acyl-trehalose (DAT) is a glycolipid located on the outer layer of the Mycobacterium tuberculosis cell envelope. Due to its noncovalent linkage to the mycobacterial peptidoglycan, DAT could easily interact with host cells located in the focus of infection. The aim of the present work was to study the effects of DAT on the proliferation of murine spleen cells. DAT was purified from reference strains of M. tuberculosis,or M. fortuitum as a surrogate source of the compound, by various chromatography and solvent extraction procedures and then chemically identified. Incubation of mouse spleen cells with DAT inhibited in a dose-dependent manner concanavalin A-stimulated proliferation of the cells. Experiments, including the propidium iodide exclusion test, showed that these effects were not due to death of the cells. Tracking of cell division by labeling with 5,6-carboxyfluorescein diacetate succinimidyl ester revealed that DAT reduces the rounds of cell division. Immunofluorescence with an anti-CD3 monoclonal antibody indicated that T lymphocytes were the population affected in our model. Our experiments also suggest that the extent of the suppressive activity is strongly dependent on the structural composition of the acyl moieties in DATs. Finally, the inhibitory effect was also observed on antigen-induced proliferation of mouse spleen cells specific for Toxoplasma gondii. All of these data suggest that DAT could have a role in the T-cell hyporesponsiveness observed in chronic tuberculosis.

Anatomy of Pilostyles hamiltonii C. A. Gardner (Rafflesiaceae) in stems of Daviesia

1982 ◽  
Vol 30 (1) ◽  
pp. 1 ◽  
Author(s):  
B Dell ◽  
J Kuo ◽  
AH Burbidge
Keyword(s):  
Vegetative Growth ◽  
Host Cells ◽  
Vascular Cambium ◽  
Flower Initiation ◽  
Nutrient Requirements ◽  
Secondary Phloem ◽  
Undifferentiated Cells ◽  
Host Parasite

In Daviesia stems the vegetative body of Pilostyles hamiltonii occurs as thin strands of undifferentiated cells within the secondary phloem of the host. Parasite cells have prominent nuclei, extended plasmalemma, and lack chloroplasts and amyloplasts. Plasmodesmata are abundant between parasite and host cells. Early vegetative growth of the parasite appears to depend on host phloem tissues for its nutrient requirements. At flower initiation Pilostyles taps the host xylem by producing pegs of tissue across the vascular cambium of the host.

scholarly journals 508 PB 254 EFFECT OF CARBON DIOXIDE ENRICHMENT ON PRODUCTION AND QUALITY OF GREENHOUSE `ROYALTY ROSES PRODUCED IN COASTAL CENTRAL CALIFORNIA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 504c-504
Author(s):  
Steven A. Tjosvold
Keyword(s):  
Carbon Dioxide ◽  
Stem Length ◽  
Total Production ◽  
Carbon Dioxide Enrichment ◽  
Flower Buds ◽  
Central California ◽  
Stems And Leaves

The atmosphere of commercial greenhouses were enriched to 1200 μl·1-1 carbon dioxide 1 hour before sunrise and maintained until ventilation was necessary to cool the greenhouse and again anytime the greenhouse vents were closed in the daytime. Enrichment was only possible, on average, for 5 daylight hours in the winter and less in the warmer months. In the first 10 month experiment, total production was not different in carbon dioxide enriched greenhouses. Stem lengths of harvested flowers were generally longer in the enriched greenhouses, particularly in the winter months. In the second 10 month experiment, total production was again not different in carbon dioxide enriched greenhouses, however, stem length was only slightly longer in the winter months. Dry weights of flower buds, stems and leaves increased slightly but only in winter months.

scholarly journals Identification and evaluation ofLonicera japonicaflos introduced to the Hailuogou area based on ITS sequences and active compounds

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7636
Author(s):  
Haiyan He ◽  
Dan Zhang ◽  
Jianing Gao ◽  
Theis Raaschou Andersen ◽  
Zishen Mou
Keyword(s):  
Cluster Analysis ◽  
Herbal Medicine ◽  
Chlorogenic Acid ◽  
Large Scale ◽  
Its Sequence ◽  
Active Components ◽  
Flower Buds ◽  
Traditional Chinese Herbal Medicine ◽  
Its Sequence Analysis ◽  
Stems And Leaves

Lonicera japonicaflos (LJF), the dried flower buds ofL. japonicaThunb., have been used in traditional Chinese herbal medicine for thousands of years. Recent studies have reported that LJF has many medicinal properties because of its antioxidative, hypoglycemic, hypolipidemic, anti-allergic, anti-inflammatory, and antibacterial effects. LJF is widely used in China in foods and healthcare products, and is contained in more than 30% of current traditional Chinese medicine prescriptions. Because of this, many Chinese villages cultivate LJF instead of traditional crops due to its high commercial value in the herbal medicine market. Since 2005, the flower buds ofL. japonicaare the only original LJF parts considered according to the Chinese Pharmacopoeia of the People’s Republic of China. However, for historical and commercial reasons, some closely related species ofLonicera Linn. continue to be mislabeled and used as LJF. Currently, there are hundreds of commercial varieties of LJF on the market and it is difficult to choose fine LJF varieties to cultivate. In this study, a total of 21 varieties labeled as LJF on the market were planted in the Hailuogou area. In order to choose the optimum variety, internal transcribed spacer (ITS) sequence alignment analysis was used to test whether the 21 varieties were genuine LJF or not. Cluster analysis of active components based on the content of chlorogenic acid and luteoloside in flower buds, stems and leaves was used to evaluate the quality of the varieties. Results demonstrated that four of the varieties wereL. macranthoidesHand.-Mazz., while the other 17 varieties wereL. japonica, and genuine LJF. The ITS sequence analysis was proven to be highly effective in identifying LJF andLoniceraeflos. Among the 17L. japonicavarieties, the amounts of chlorogenic acid and luteoloside in flower buds, stems and leaves were significantly different. Based on the cluster analysis method, the variety H11 was observed to have the highest level of active components, and is therefore recommended for large-scale planting in the Hailuogou area.

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