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141.
Isolation, Nucleotide Sequence, and Physiological Relevance of the Gene Encoding Triose Phosphate Isomerase from Kluyveromyces lactis 下载免费PDF全文
Concetta Compagno Francesco Boschi Agnese Daleffe Danilo Porro Bianca Maria Ranzi 《Applied microbiology》1999,65(9):4216-4219
Lack of triose phosphate isomerase activity (TIM) is of special interest because this enzyme works at an important branch point of glycolytic flux. In this paper, we report the cloning and sequencing of the Kluyveromyces lactis gene encoding TIM. Unlike Saccharomyces cerevisiae ΔTPI1 mutants, the K. lactis mutant strain was found to be able to grow on glucose. Preliminary bioconversion experiments indicated that, like the S. cerevisiae TIM-deficient strain, the K. lactis TIM-deficient strain is able to produce glycerol with high yield. 相似文献
142.
The mechanism of infection by Vibrio sp. P11 promoting the ice-ice disease in Kappaphycus alvarezii was investigated in vitro.
Its intensity of infection differs from that of another ice-ice promoter (Cytophaga sp. P25) by promoting the disease much
faster. However, when secondary infection by other bacteria starts, its ability to compete with these bacteria gradually diminishes,
whereas, infection by P25, although not displaying such drastic effects as P11, shows consistent competitive ability against
other bacteria. Time-series infection experiments with application of polyclonal antibodies to specifically detect Vibrio
sp. P11 revealed that this bacterium has a high affinity for the seaweed especially when the latter is stressed. It promotes
the disease after a rapid increase in cell density of up to 107 g−1 (wet wt.) in the first 24 h. This bacterial cell build-up may take only 1–2 h on stressed thalli, but takes about 24 h on
non-stressed thalli. Build-up is not sustainable in non-stressed thalli as high density is usually followed by a sudden decline
in cell number believed to result from an algal defence against potential pathogens. Inoculation of the bacterium on thalli
incubated in continuous culture system extends the time of bacterial attachment due to laminar flow and, possibly, competition
by existing bacteria on the seaweed surface and in ambient seawater medium. Motility-driven cell attachment by this bacterium
is suggested as an important factor for infection.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
143.
144.
Fábio Henrique Krenchinski Leandro Paiola Albrecht Alfredo Junior Paiola Albrecht Victor José Salomão Cesco Danilo Morilha Rodrigues Roberto Luis Portz Luiz Henrique Saes Zobiole 《Acta Physiologiae Plantarum》2017,39(2):63
The planting of RR2 Intacta soybeans by farmers has been expanding strongly. However, some visual injuries have been noted after glyphosate application. The aim of this study was to evaluate the influence of glyphosate application on chlorophyll, photosynthesis and water use of four Intacta RR2 soybean cultivars. The experiment was conducted in a greenhouse, in a randomized block design with a 3 × 4 factorial scheme, consisting of three glyphosate rates and four soybean cultivars. The glyphosate formula used was isopropylamine salt + potassium salt. The parameters analyzed were phytotoxicity at 7, 14, 21 and 28 days after application, and total chlorophyll index at 0, 3, 7, 14, 21, 28, 35, 42 and 49 days after application. Furthermore, 40 days after application, the net CO2 assimilation rate (A), transpiration rate (E), stomatal conductance (G), and internal CO2 concentration (Ci) were evaluated as well. The water-use efficiency (WUE) and carboxylation efficiency were calculated. The data were submitted to analysis of variance and compared by the Tukey’s test (p ≤ 0.05), followed by regression analysis. The phytotoxicity influence could be seen until 21 days after application, in which Monsoy 6210 IPRO cultivar was the most injured. The increasing doses promoted a reduction of the chlorophyll level up to 35 days after application in Monsoy 6410 IPRO. The cultivars tested here showed similar chlorophyll index values. On the 3rd, 7th and 14th DAA (Fig. 5a–c), there was a significant linear decline in the chlorophyll index with rising glyphosate dose for all four cultivars. The chlorophyll index cultivars were not influenced by the doses on the 42nd and 49th DAA. There was no difference in water use and carboxylation efficiency. The parameters A, E and A/Ci showed a positive correlation as the doses increased, while Ci declined, in both cultivars. The application of glyphosate on these soybean cultivars causes different injuries according to the sensitivity. In general, RR2 soybeans have the ability to recover from visual intoxication injuries and reestablish the normal chlorophyll production and photosynthetic parameters after glyphosate application. 相似文献
145.
Growth and development of conifer pollen tubes 总被引:1,自引:0,他引:1
Conifer pollen tubes are an important but underused experimental system in plant biology. They represent a major evolutionary
step in male gametophyte development as an intermediate form between the haustorial pollen tubes of cycads and Ginkgo and the structurally reduced and faster growing pollen tubes of flowering plants. Conifer pollen grains are available in
large quantities, most can be stored for several years, and they grow very well in culture. The study of pollen tube growth
and development furthers our understanding of conifer reproduction and contributes towards our ability to improve on their
productivity. This review covers taxonomy and morphology to cell, developmental, and molecular biology. It explores recent
advances in research on conifer pollen and pollen tubes in vivo, focusing on pollen wall structure, male gametophyte development
within the pollen wall, pollination mechanisms, pollen tube growth and development, and programmed cell death. It also explores
recent research in vitro, including the cellular mechanisms underlying pollen tube elongation, in vitro fertilization, genetic
transformation and gene expression, and pine pollen tube proteomics. With the ongoing sequencing of the Pinus taeda genome in several labs, we expect the use of conifer pollen tubes as an experimental system to increase in the next decade. 相似文献
146.
147.
Fire is an important ecological factor that structures savannas, such as the cerrado, by selecting plant species and altering soil nutrient content. In Emas National Park, central Brazil, we compared soils under three different fire regimes and their relationship to the cerrado species they support. We collected 25 soil and vegetation samples at each site. We found differences in soil characteristics (p?<?0.05), with fertility and fire frequency positively related: in the annually burned site we found higher values of organic matter, nitrogen, and clay, whereas in the protected site we detected lower values of pH and higher values of aluminum. We also observed differences in plant community structure, with distinct floristic compositions in each site. Floristic composition was more related to sand proportion (intra-set correlation?=?0.834). Different fire frequencies increase environmental heterogeneity and beta diversity in the Brazilian cerrado. 相似文献
148.
Danilo G. Ceschin María C. Sánchez Gustavo A. Chiabrando 《Journal of cellular biochemistry》2009,106(3):372-380
Low‐density lipoprotein receptor‐related protein 1 (LRP1) is an endocytic receptor, which binds and internalizes diverse ligands such as activated α2‐macroglobulin (α2M*). LRP1 promotes intracellular signaling, which downstream mediates cellular proliferation and migration of different types of cells, including macrophages. Unlike the LDL receptor, LRP1 expression is not sensitive to cellular cholesterol levels but appears to be responsive to insulin. It has been previously demonstrated that insulin increases the cell surface presentation of LRP1 in adipocytes and hepatocytes, which is mediated by the intracellular PI3K/Akt signaling activation. The LRP1 protein distribution is similar to other insulin‐regulated cell surface proteins, including transferring receptor (Tfr). However, in macrophages, the insulin effect on the LRP1 distribution and expression is not well characterized. Considering that macrophages play a central role in the pathogenesis of atherosclerosis, herein we evaluate the effect of insulin on the cellular expression of LRP1 in J774 macrophages‐derived cells using Western blot and immunofluorescence microscopy. Our data demonstrate that insulin induces a significant decrease in the LRP1 protein content, without changing the specific mRNA level of this receptor. Moreover, insulin specifically affected the protein expression of LRP1 but not Tfr. The insulin‐induced protein degradation of LRP1 in J774 cells was mediated by the activation of the PI3K/Akt pathway and proteasomal system by an enhanced ubiquitin–receptor conjugation. The decreased content of LRP1 induced by insulin affected the cellular internalization of α2M*. Thus, we propose that the protein degradation of LRP‐1 induced by insulin in macrophages could have important effects on the pathogenesis of atherosclerosis. J. Cell. Biochem. 106: 372–380, 2009. © 2008 Wiley‐Liss, Inc. 相似文献
149.
Tiago F. Carrijo Divino Brandão Danilo E. de Oliveira Diogo A. Costa Thiago Santos 《Journal of Insect Conservation》2009,13(6):575-581
The advance of agricultural frontier may cause the Cerrado (Brazilian savanna) to disappear before 2030. This work focuses
on measuring the impact of pasture implantation on a cerrado’s termite fauna. Termites were sampled in a cerrado sensu stricto
and a pasture, originally cerrado. All species were classified as their feeder group, accumulation curves were made and Shannon-Wiener
indexes and β diversity were calculated for both areas. Cerrado was richer than pasture and species composition differed considerably,
leading β diversity to a high value. The humivorous was the most representative species, followed by grass/litter feeders, xylophagous
and, less representative, the intermediates. There were more xylophagous and intermediates species on cerrado than in pasture;
the grass/litter feeders were more abundant in pasture, but didn’t differed in number or species; and humivorous didn’t differed
neither in richness nor in abundance. This work shows that the simplification of the habitat is indeed causing the extinction
of populations that depend on some specifics resource. 相似文献
150.
Emanuela Giombini Massimiliano Orsini Danilo Carrabino Anna Tramontano 《BMC bioinformatics》2010,11(1):39