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101.
Lin Hsueh-Shih De Jeu Marjo J. Jacobsen Evert 《Plant Cell, Tissue and Organ Culture》1998,52(3):165-169
Direct shoot regeneration was induced from leaf explants of Alstroemeria. The explants contained a leaf blade and a small
portion of stem node, which were cut from the erect shoots of in vitro multiplicated plantlets. The shoot regeneration capacity
of the excised leaf explants was significantly related to the position of the explant on the stem. The youngest explant which
was located closest to the shoot apex gave the highest response. A gradient response toward the shoot apex was observed in
percentage of shoot regeneration and in the number of shoots per regenerating explant. Histological studies revealed that
the shoots were initiated at the leaf axils. The origin of the adventitious buds was located at the epidermal layer of stem
peripheral cells.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
102.
Summary
Betula pollen production and flowering, pollen transport and pollen deposition are considered for the mountain birch region of northern
Finland for the ten-year period 1984–1993. The most abundant flowering year was 1989 and, after that, 1985. In these years
the highest values were also recorded for pollen in the air. There is a significant correlation between the amount of pollen
released and the thermal sum of the previous year. In terms of pollen deposition the peak years were 1989 and 1986. The correlation
between the amount of pollen in the air and that being deposited on the ground is also statisticaly significant. It is evident
that some birch pollen is already present in the air before local flowering begins and that, in some years, this non-local
pollen can account for more than 20% of the yearly total. This preflowering proportion was highest in 1985 and 1993, the latter
being a prolific flowering year in the south of the country. There is a clear relationship between the proportion of the non-local
pollen in the air and the proportion ofBetula pubescens/pendula type pollen deposited on the ground and, conversely, there is a significant correlation between the amount of local pollen
in the air and the amount ofBetula tortuosa plusB. nana type pollen being deposited on the ground. The questions both of the viability of this long-distance pollen and of its ability
to cause allergic reactions are considered. An assessment is also made of the degree to which fossil birch pollen assemblages
can be realistically interpreted in terms of local vegetation if a varying proportion of the same pollen type is non-local. 相似文献
103.
104.
105.
Marisa I. Mendes Mariana Gutierrez Salazar Kether Guerrero Isabelle Thiffault Gajja S. Salomons Laurence Gauquelin Luan T. Tran Diane Forget Marie-Soleil Gauthier Quinten Waisfisz Desiree E.C. Smith Cas Simons Marjo S. van der Knaap Iris Marquardt Aida Lemes Hanna Mierzewska Bernhard Weschke Wolfgang Koehler Geneviève Bernard 《American journal of human genetics》2018,102(4):676-684
106.
Summary Pollen and spore concentrations were compared in Tartu, Estonia and in three sites in Finland (Turku, Kuopio and Oulu) during
May–September 1989. The onset ofQuercus, Pinus, Poaceae,Urtica andRumex flowering started earlier in Tartu than at any site in Finland. The flowering ofJuniperus andArtemisia, on the other hand, began earlier in Turku and Kuopio than in Tartu.Pinus andJuniperus showed a significant correlation (number of pollen grains at the same date) between Tartu and Turku and between Turku and
Kuopio. Poaceae andUrtica were correlated between all the sites, as wasRumex except between Tartu and Turku.Artemisia was correlated between Tartu and Turku, Turku and Oulu, and Kuopio and Oulu.Cladosporium correlated between Tartu and Turku. The pollen seasons of Poaceae,Urtica andRumex are prolonged towards the south. 相似文献
107.
Heli Ruotsalainen Maija Risteli Chunguang Wang Yu Wang Marjo Karppinen Ulrich Bergmann Ari-Pekka Kvist Helmut Pospiech Karl-Heinz Herzig Raili Myllyl? 《PloS one》2012,7(11)
Lysyl hydroxylase 3 (LH3) has lysyl hydroxylase, galactosyltransferase, and glucosyltransferase activities, which are sequentially required for the formation of glucosylgalactosyl hydroxylysines in collagens. Here we demonstrate for the first time that LH3 also modifies the lysine residues in the collagenous domain of adiponectin, which has important roles in glucose and lipid metabolism and inflammation. Hydroxylation and, especially, glycosylation of the lysine residues of adiponectin have been shown to be essential for the formation of the more active high molecular weight adiponectin oligomers and thus for its function. In cells that totally lack LH3 enzyme, the galactosylhydroxylysine residues of adiponectin were not glucosylated to glucosylgalactosylhydroxylysine residues and the formation of high and middle molecular weight adiponectin oligomers was impaired. Circulating adiponectin levels in mutant mice lacking the lysyl hydroxylase activity of LH3 were significantly reduced, which indicates that LH3 is required for complete modification of lysine residues in adiponectin and the loss of some of the glycosylated hydroxylysine residues severely affects the secretion of adiponectin. LH mutant mice with reduced adiponectin level showed a high fat diet-induced increase in glucose, triglyceride, and LDL-cholesterol levels, hallmarks of the metabolic syndrome in humans. Our results reveal the first indication that LH3 is an important regulator of adiponectin biosynthesis, secretion and activity and thus might be a potential candidate for therapeutic applications in diseases associated with obesity and insulin resistance. 相似文献
108.
Leukoencephalopathy with vanishing white matter (VWM) is one of the most prevalent inherited white-matter disorders, especially in Caucasian populations. VWM is unusual because of its sensitivity to febrile infections and minor head trauma. The basic defect of this enigmatic brain disease resides in the regulation of initiation of protein synthesis. Recently, undue activation of the unfolded-protein response has emerged as an important factor in the pathophysiology of VWM. Here, we discuss the mechanisms that might be responsible for the selective involvement of the brain white matter in VWM. At present, VWM research is in need of an animal model to study disease mechanisms and therapeutic interventions. 相似文献
109.
Model systems can facilitate and focus research efforts but ill-chosen or inapt ones can distract or impede scientific progress. In this Opinion article, we pose the question: how can the literature provide appropriate general conclusions if the model systems upon which the literature is based are unrepresentative of the relevant biological diversity? A good example of this problem is the endophyte-grass symbiosis, which is considered to be a classic example of mutualistic interactions. Meta-analysis of the primary literature demonstrates that the conceptual framework for endophyte-grass interactions has largely been based on endophyte-plant-herbivore studies of two agricultural grass species, tall fescue and perennial ryegrass. Consistent with conventional wisdom, the meta-analysis indicates that endophytes slightly increase grass resistance to herbivores. By contrast, endophytes appear not to affect plant performance or competitive ability. The positive effects of endophytes appear to be dependent on genetic variation in the host and endophyte, and on nutrient availability in soils. Thus, the agronomic grass model systems fail to capture the breadth of variability inherent in wild grass-endophyte populations and communities. 相似文献
110.
Lilleväli K Haugas M Matilainen T Pussinen C Karis A Salminen M 《Mechanisms of development》2006,123(6):415-429
Inner ear develops from an induced surface ectoderm placode that invaginates and closes to form the otic vesicle, which then undergoes a complex morphogenetic process to form the membranous labyrinth. Inner ear morphogenesis is severely affected in Gata3 deficient mouse embryos, but the onset and basis of the phenotype has not been known. We show here that Gata3 deficiency leads to severe and unique abnormalities during otic placode invagination. The invagination problems are accompanied often by the formation of a morphological boundary between the dorsal and ventral otic cup and by the precocious appearance of dorsal endolymphatic characteristics. In addition, the endolymphatic domain often detaches from the rest of the otic epithelium during epithelial closure. The expression of several cell adhesion mediating genes is altered in Gata3 deficient ears suggesting that Gata3 controls adhesion and morphogenetic movements in early otic epithelium. Inactivation of Gata3 leads also to a loss of Fgf10 expression in otic epithelium and auditory ganglion demonstrating that Gata3 is an important regulator of Fgf-signalling during otic development. 相似文献