Search results for " growth"
showing 10 items of 4263 documents
Effects of UVB radiation exposure from the molecular to the organism level in macrophytes from shallow Mediterranean habitats
2015
Abstract The available data on the effects of UVB radiation (UVBR) are scarce for submerged macrophytes, particularly charophytes. We studied the effects of UVBR on Chara baltica, Chara hispida, Chara vulgaris, Nitella hyalina and Myriophyllum spicatum, collected from shallow Mediterranean waterbodies. In a short-term laboratory experiment, we subjected these species to three different UVBR treatments corresponding to daily biologically effective integrated doses of 0, 1 and 6 kJ m−2. The analysed response variables were DNA damage, UV-absorbing compounds (both the methanol-soluble–SUVACs- and, for the first time in charophytes, the methanol-insoluble cell wall-bound fraction–WUVACs-), the …
Research on the Diurnal Courses of Abscissic Acid, 1-Aminocyclopropane Carboxylic Acid and Its Malonyl Conjugate Contents in Needles of Damaged and U…
1993
Ethylene regulates many aspects of plant growth, development and senescence. The immediate precursor of ethylene was identified as 1-aminocyclopropane carboxylic acid (ACC) [7]. Amrhein et al. [1] discovered that ACC supplied exogenously was efficiently converted into ACC malonyl conjugate (MACC) along with ethylene production.
Plant-growth-regulatingN-(phosphonoacetyl)amines
1994
A series of N‐(phosphonacetyl)amine derivatives were synthesized and screened for plant‐growth regulating activity on Lepidium sativum L. and Cucumis sativus L. Aromatic N‐(phosphonoacetyl)amines. which may be considered as possible analogues of N‐acylaniline herbicides obtained by replacement of their acyl group by the phosphonacetyl moiety, exhibited significant or moderate herbicidal activity. In contrast, N‐(phosphonoacetyl)amino acids and N‐(phosphonoacetyl)aminophosphonic acids promoted the growth of L. sativum and C. sativus roots.
Demonstration and study of characters of foliar « compensatory growth» phenomenon in grapevine (<em>Vitis vinifera</em> L.)
1996
<p style="text-align: justify;">Defoliation and decapitation experiments showed that the growth of a grapevine leaf was inhibited by both the terminal bud and the younger higher leaves. There is a phenomenon of synergy between these two influences. A young leaf freed of these two influences showed a higher growth rate than the norm ; this is « compensatory growth ». It is when a leaf is in its phase of maximal growth that it is most able to realize this &amp;laquo compensatory growth ». This is not due to a longer growth time, but more to a faster growth rate. This « compensatory growth » is not the consequence of competition between leaf growth and internodal elongation. Exogenou…
Synthesis of the neurotoxin quinolinic acid in apoptotic tissue from Suberites domuncula: cell biological, molecular biological and chemical analyses
2002
Sessile marine animals, such as sponges, are prone to infection by prokaryotic as well as by eukaryotic attacking organisms. In the present study we document for the first time that in tissue from sponges which underwent apoptosis, a toxic compound is produced which very likely controls the elimination of the dying tissue. The marine sponge Suberites domuncula develops in the field occasionally apoptotic tissue areas which are rapidly eliminated. In the present study apoptosis was induced in S. domuncula by exposing the specimens in aquaria to 5 µg/ml Dip or by maintaining the sponges for 3 - 5 days under non-aeration conditions. After that treatment only one eukaryotic epibiont, the mollus…
Improved micropropagation in Polygala myrtifolia
2004
Stem segments from apical shoot tips of Polygala myrtifolia were used as primary explants to establish in vitro cultures. Axillary shoots produced on noncontaminated explants were excised and recultured in the same medium to increase the stock of shoot cultures. Equal molar concentrations of five cytokinins 2-isopentenyladenine (2iP), kinetin, zeatin, N6-benzyladenine (BA) and adenine were tested for ability to induce axillary shoot development from double node stem segments. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog agar medium supplemented with 1.8 M BA. Seven indole-3-acetic acid (IAA) concentrations (2.8, 5.7, 8.6, 11.4, 14.3, 17.1 M) were t…
Kultivierung humaner Zellen auf polymerbeschichteten Bioimplantaten?ein neues Konzept zur Verbesserung der Implantateigenschaften
2004
BACKGROUND AND PURPOSE Calcific degeneration with the resulting need for operative replacement remains the major drawback of bioprostheses. Previous studies have shown that cellular surface seeding decreases calcium uptake in vitro and in vivo, but complete coverage remains difficult to achieve. A new approach is presented, masking glutaraldehyde residues with a covalently bound polymer layer thus facilitating cell seeding. The aim of this study was to evaluate different polymers for their ability to promote surface cell adhesion and formation of complete monolayers. MATERIAL AND METHODS Ten ultrathin polymers, covalently bound to glass and exhibiting different physicochemical characteristi…
Cardenolide variation within and among natural populations of Digitalis obscura
1999
Summary Cardenolide content in 49 wild-growing Digitalis obscura plants from six natural populations on the Iberian Peninsula was determined by HPLC. Series A and B glycosides were the predominant cardenolides in all samples, but absolute values varied among and within populations. Hierarchic analysis of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Furthermore, analyses from greenhouse-grown plants, generated from seeds collected from selected parental genotypes, attributed nearly all the variability in cardenolide content to single plants. Some individual plants showed a leaf content …
Diabetic Retinopathy and Oxidative Stress
2014
Abstract Diabetic retinopathy (DR) is the leading cause of acquired blindness in working age adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in macroscopic retinal damage that can be assessed by funduscopy. The overproduction of reactive oxygen species (ROS) in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidatively induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins and DNA, leading to cell death…
Neuroprotective, antioxidant and antiproliferative activity of grapefruit IntegroPectin on SH-SY5Y cells
2021
AbstractTested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful neuroprotective, antioxidant and antiproliferative agent. The strong antioxidant properties of grapefruit IntegroPectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make this new biopolymer highly soluble in water an attractive therapeutic agent for oxidative stress-associated brain disorders. Similarly, the ability of this new citrus pectin rich in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface to inhibit cell proliferation or even kill, at high doses, neoplastic cells, coupled to its…