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991.
Satoshi?SaitoEmail author Tamotsu?Sato Yohsuke?Kominami Dai?Nagamatsu Shigeo?Kuramoto Takeshi?Sakai Ryuichi?Tabuchi Atsushi?Sakai 《Trees - Structure and Function》2004,18(4):486-491
The vertical foliage distribution of Castanopsis cuspidata (Thunb.) Schottky was examined in trees of various sizes to clarify its variation in relation to tree size and the light environment in a stand. As indices of these parameters, we analyzed crown social position (CSP: percent of stand height) and specific leaf area (SLA). The vertical foliage distribution of trees was expressed by a Weibull function. The variation in the vertical foliage distribution of C. cuspidata could be categorized into three types using crown social position and light environment. In the first type, leaves were concentrated to the top 20% of the tree; such trees are canopy trees that can receive full sunlight. The second type had a large relative crown depth and an asymmetric distribution with the maximum foliage located near the top of the tree; such trees are suppressed trees whose crowns do not receive sufficient light. The third type had a large relative crown depth and a symmetric distribution; such trees occur in high light environments, although their crowns are in the understory layer. The differences in the vertical foliage distribution are related to the strategies used to capture light. Multiple regression analysis showed that CSP and SLA at the top layer of the tree explained successive changes in the vertical foliage distribution. These results will contribute to scaling-up the vertical foliage distribution to the community level in pure stands of C. cuspidata using an individual-based model. 相似文献
992.
Skirpan AL Dowd PE Sijacic P Jaworski CJ Gilroy S Kao TH 《Plant molecular biology》2006,61(4-5):553-565
Oxysterol-binding proteins (OSBPs) and oxysterol-binding-protein related proteins (ORPs) are encoded by most eukaryotic genomes
examined to date; however, they have not yet been characterized in plants. Here we report the identification and characterization
of PiORP1, an ORP of Petunia inflata that interacts with the cytoplasmic kinase domain of a receptor-like kinase, named PRK1, of P. inflata. PiORP1 is phosphorylated by PRK1 in vitro and therefore may be involved in PRK1 signaling during pollen development and growth. RNA gel blot analysis showed that PiORP1 and PRK1 had very similar expression patterns in developing pollen, mature pollen and pollen tubes. GFP fusion proteins of PiORP1
localized in the plasma membrane of pollen tubes at distinct foci and its PH domain alone was sufficient to mediate this localization.
The sequence for the oxysterol-binding domain of PiORP1 was used to search the genome of Arabidopsis; 12 ORPs were identified and phylogenetic analysis revealed that they fell into two distinct clades, consistent with the ORPs of other
eukaryotes. RT-PCR analysis showed that all 12 Arabidopsis ORPs were expressed; 10 were expressed in most of the tissues examined under normal growth conditions, but only three were expressed
in pollen.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users.
GenBank accession number for PiORP1: DQ241801 相似文献
993.
AIMS: To carry out a rapid and reliable identification of bacterial diversity in the oyster Crassostrea gigas from Todos Santos Bay, México, in the current study we applied the molecular techniques of fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR). In order to reach this goal, genus and group-specific oligonucleotides targeted to 16S rDNA/rRNA were used. METHODS AND RESULTS: Oysters were collected and different tissues were analysed by means of culture-independent methodologies. In the digestive glands and gonads gamma-Proteobacteria and Gram-positive bacteria with a low G+C content, were identified as metabolically active by FISH. In the oyster gills a higher active diversity was observed, including Gram-positive bacteria with a low and high G+C content, members of the Cytophaga/Flavobacterium cluster and gamma-Proteobacteria. Consistent with FISH analysis, the amplification of 16S rDNA genes fragments with genus and group-specific oligonucleotides confirmed the presence of the same groups, as well as members of the alpha- and beta-Proteobacterias, Pseudomonas spp. and Bacillus spp. CONCLUSIONS: The combination of accurate and very easy-to-apply molecular methods allowed us to carry out a rapid screening of high bacterial diversity in oysters. SIGNIFICANCE AND IMPACT OF THE STUDY: This work is the first report about bacterial diversity in oyster tissues analysed by FISH and PCR, without using culture-dependent methods and allowed us to determine the phylogenetic diversity of the bacterial communities present in oyster cultures, including bacteria with and without metabolic activity, as well as uncultivable cells, which are generally underestimated by traditional identification. 相似文献
994.
Effect of controlled carbon dioxide on in vitro shoot multiplication in Feronia limonia (L.) Swingle
The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was
insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO2), was found to be inadequate for sustainable growth and multiplication of shoots. The carbon dioxide enrichment promoted
shoot multiplication and overall growth. The promotory effect of CO2 was independent of the presence of sucrose in the medium. In the presence of both CO2 and sucrose, an additive effect was observed producing maximum shoot growth. In the absence of sucrose a higher concentration
of CO2 (10.0)g m−3 was required to achieve photoautotrophic shoot multiplication comparable to ambient air controls. Highest leaf area per shoot
cluster promoting shoot growth and multiplication was recorded under this treatment. Shoots growing on sucrose containing
medium under controlled CO2 environment of 0.6 g m−3 concentration evoked better response than ambient air controls (shoots growing on sucrose containing medium) in growth room.
This treatment produced the overall best response. The present study highlighted the possibility of photoautotrophic multiplication
which might prove useful for successful hardening and acclimatization in tissue culture plants. 相似文献
995.
Kuo MT Wei Y Yang X Tatebe S Liu J Troncoso P Sahin A Ro JY Hamilton SR Savaraj N 《Biochemical and biophysical research communications》2006,340(3):887-893
A novel gene designated as fragile site-associated (FSA) gene was recently identified by positional cloning from the CHO 1q31 fragile site which plays an important role in regulating amplification of multidrug resistance (mdr1) gene in multidrug-resistant cells. FSA produces a message of approximately 16 kb which encodes an open-reading frame of 5005 amino acids. FSA shares sequence similarity with that in Caenorhabditis elegans lpd-3, a lipid storage gene. Using immunohistochemical staining and RNA in situ hybridization we report here that expression of FSA is associated with developmental programs of spermatogenesis and mammary gland in mice. Real-time RT-PCR results also support the upregulation of FSA expression in mammary gland development. Expression of FSA in many tissues including colon, skin, ovary, prostate, and bladder is mainly in the postmitotic, well-differentiated compartments. Moreover, levels of FSA expression are downregulated in tumors of these tissue origins. These results suggest that FSA also plays important roles in regulating mammalian epithelial growth and differentiation and tumor development. 相似文献
996.
Characteristics of net ecosystem carbon dioxide exchange (NEE) from August to October of Alpine meadow on the Tibetan Plateau, China 总被引:3,自引:0,他引:3
Xu Lingling Zhang Xianzhou Shi Peili Yu Guirui Sun Xiaomin 《Frontiers of Biology in China》2006,1(4):418-422
The Alpine meadow is one of the vegetation types widely distributed on the Tibetan Plateau in China with an area of about
1.2 million square kilometers. The Damxung rangeland station, located in the hinterland of the Tibetan Plateau, is covered
with an typical vegetation. The continuous carbon flux data (from August to middle October, 2003) measured with the open-path
eddy covariance system was used to analyze the diurnal variation pattern of net ecosystem carbon dioxide exchange (NEE) and
its relationship with the environmental factors, such as photosynthetically active radiation (PAR), precipitation, and temperature.
Results showed that NEE presented obvious diurnal variation pattern with single-peak of diurnal maximum carbon assimilation
at 11: 00–12: 00 (local time) with an average of −0.268 mg CO2·m−2·s−1, i.e., −6.08 μmol CO2·m−2·s−1. During the daytime, NEE fitted fairly well with PAR in a rectangular hyperbola function with the apparent quantum yield
(0.020 3 μmol CO2 μmol−1 PAR) and maximum ecosystem assimilation (9.741 1 μmol CO2·m−2·s−1). During the night-time, NEE showed a good exponential relation with the soil temperature at 5 cm depth.
__________
Translated from Acta Ecologica Sinica 2005, 25(8): 1948–1952 [译自: 生态学报, 2005, 25(8): 1948–1952] 相似文献
997.
Cui?Yu Dongwei?Hu Jiahong?Dong Xiaofeng?Cui Junjie?Wu Jialin?Yu Xueping?ZhouEmail author 《中国科学C辑(英文版)》2004,47(6):503-509
Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV) are two closely related viruses in the genus Tobamovirus, but they induce obviously different sizes of necrotic lesions in tobacco plants containing the N gene. Comparison of the symptoms produced by TMV, ToMV and a chimaeric virus (T/OMP), in which the TMV movement protein (MP)
gene was replaced by the ToMV MP gene, showed T/OMP caused necrotic lesions that were similar in size to those of ToMV in tobacco plants containing the N gene. The coat protein and MP of the three viruses accumulated in planta with similar levels, and the replication level of TMV and T/OMP in protoplasts also had no difference. Comparison of the
activities of defense-related enzymes (PAL, POD and PPO) induced by the three viruses also showed that the variability of
enzyme activity induced by T/OMP was similar to that induced by TMV, but different from that induced by ToMV. The results
indicate that the size difference of necrotic lesions induced by TMV and ToMV in tobacco plants containing the N gene results from the functional difference of their MP genes. 相似文献
998.
Douglas M. Templeton Anna Paudyn Andrew D. Baines 《Biological trace element research》1989,22(1):17-33
Interest in the biological behavior of a growing number of elements, along with increasing recognition of the importance of interactions among them, demands a versatile and reliable technique for multielement analysis of biological samples. Significant improvements over the sensitivity achieved with conventional inductively coupled plasma (ICP) optical emission spectrometries have been realized with the introduction of quadrupole mass spectrometry (MS) for detection of ions in the plasma. The hybrid technique of ICP-MS promises to be a method of rapid multielement analysis, at detection limits that approach or surpass those of other technologies. However, the application of ICP-MS to analyses of biological interest is truly in its infancy. Here we report the use of ICP-MS for the determination of more than 30 elements of biological interest in a tissue and a biological fluid (rat liver and serum, respectively). Experimental values of the elements serve as a basis for discussion of analytical protocols, performance criteria, and certain problems peculiar to ICP-MS. 相似文献
999.
Gymnodinium aeruginosum has the usual fine structure of a dinoflagellate but does not seem to contain a well elaborated peduncle or a microtubular basket. Naked cells are surrounded by a single large amphiesmal vesicle. It houses an endosymbiont with typical blue-green cryptophycean chloroplasts (generally only one), cryptophycean starch grains in the periplastidal cytoplasm without a nucleomorph, and two membranes separating the periplastidal cytoplasm from the cryptophycean cytoplasm which contains mitochondria, ER, vesicles and ribosomes, but no eukaryotic nucleus. The endosymbiont is surrounded by a single membrane. Possible ways of the acquisition of the endosymbiont and the problem of the existence of ribosomes within a compartment without nucleus are discussed.Devoted to Prof. Dr.L. Geitler, the Nestor of phycology and endosymbiosis research, on the occasion of the 90th anniversary of his birthday. 相似文献
1000.
陈道亮 《分子细胞生物学报》1989,(1)
本研究以爪蟾胚胎内胚层细胞间连接通讯发育的时程为指标,观察了cAMP和依赖cAMP的蛋白激酶催化亚基对这一发育的影响。将依赖cAMP的蛋白激酶催化亚基注射入爪蟾胚胎四细胞期的每一个细胞可使该胚胎内胚层细胞间连接通讯的发育明显加快,提示在正常状态下这一发育的进程是受细胞内依赖cAMP的磷酸化水平的制约。但用双丁酰cAMP和磷酸二酯酶抑制剂对胚胎进行培育,或将cAMP和磷酸二酯酶抑制剂注射入胚胎细胞,对这一发育并无影响,可能是由于这些胚胎细胞内依赖cAMP的蛋白激酶的实际有效含量较低而cAMP含量较高所致。注射这种蛋白激酶催化亚基所诱导的胚胎细胞间连接通讯在注射后约8.5小时出现。这一时间比前人在哺乳动物细胞培养中用cAMP或必需的信使RNA诱导出细胞间连接通讯所需要的时间(2—4小时)长得多,提示在胚胎中依赖cAMP的磷酸化对细胞间连接通讯发育的作用是从RNA转录的水平上开始的。 相似文献