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Archegonium and fertilization in Coniferopsida 总被引:1,自引:0,他引:1
Key message
This paper reviews studies on the origin and development of the Coniferopsida’s archegonium, illustrates the relationship between the archegonium and fertilization, and discusses the molecular regulation of archegonium development.Abstract
This paper reviews studies on the origin and development of the Coniferopsida’s archegonium and discusses the characteristics of the archegonial cells and the molecular regulation of archegonium development. There are some main conclusions which could be drawn from this review. (1) It enables the precise position of the archegonium in the ovule to be determined as well as its structural features. (2) The functions of the neck cells in Coniferopsida are that they may serve as channels for sperms to enter the archegonia and lead the growth of pollen tubes. (3) The proteid vacuoles in egg cell may provide nutrition for fertilization and lead to the paternal inheritance of plastids in some Coniferopsida. (4) The uniparental transmission of plastids results from “the active digestion of male organelle nuclei (genomes) in young zygotes” in almost all Coniferopsida. (5) The studies on the molecular regulation of the archegonium and fertilization in Coniferopsida are still very limited and that is the direction for further research. In summary, the review provides a theoretical basis for further study on the developmental and reproductive biology of the Coniferopsida.2.
Yuichi Kagotani Keisuke Nishida Takashi Kiyomizu Keisuke Sasaki Atsushi Kume Yuko T. Hanba 《Trees - Structure and Function》2016,30(3):697-708
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Stomatal regulation involves beneficial effects of pruning mulch and irrigation on leaf photosynthesis in Prunus yedoensis and Ginkgo biloba under moderate drought. G. biloba showed conservative water use under drought.Abstract
Leaf photosynthesis is highly sensitive to soil water stress via stomatal and/or biochemical responses, which markedly suppress the growth of landscape trees. Effective irrigation management to maintain leaf photosynthesis and information on species-specific photosynthetic responses to soil water stress are essential for the sustainable management of landscape trees in Japan, in which summer drought often occurs. In order to investigate effective irrigation management, we used plants with moderate soil water stress as controls, and examined the effects of daily irrigation and pruning mulch on leaf photosynthesis in container-grown Ginkgo biloba and Prunus yedoensis, which are the first and second main tall roadside trees in Japan. Stomatal conductance was significantly increased by pruning mulch and daily irrigation, with similar increases in leaf photosynthesis being observed in P. yedoensis and G. biloba. In order to obtain information on species-specific photosynthetic responses to soil water stress, we compared the responses of leaf photosynthesis and leaf water status to reductions in soil water content (SWC) between the two species. G. biloba maintained a constant leaf water potential, leaf water content, maximum carboxylation rate, and electron transport rate with reductions in SWC, whereas reductions were observed in P. yedoensis. We concluded that pruning mulch and irrigation effectively offset the negative impact of moderate water stress on leaf photosynthesis in summer in P. yedoensis and G. biloba via stomatal regulation, and also that G. biloba maintained its photosynthetic biochemistry and leaf water status better than P. yedoensis under severe water stress.3.
Tokushiro Takaso Yukitoshi Kimoto John N. Owens Masumi Kono Tetsuro Mimura 《Sexual plant reproduction》2013,26(1):17-23
In cycads, spermatozoids are released from pollen tubes and swim in fluid toward the archegonia. The source of this fluid was examined using Cycas revoluta Thunb. ovules placed in culture. Dissected female gametophytes just before fertilization produced copious fluid on their upper surface. The fluid first appeared around the archegonial chamber and then on the inside of the archegonial chamber. When this fluid was applied to dry turgid pollen tubes, they discharged spermatozoids 12 h later. The archegonial neck appeared as two semi-spherical swellings, whereas the four neck cells later became visible and they separated in a schizogenous manner. Many globose particles appear on the top of the archegonial neck cells when the fluid is present. The contents of pollen tubes, spermatozoids and surrounding liquid intermingle with the secreted fluid. The female gametophyte differs in ultrastructure during the stages before and after fluid secretion, the latter showing changes suggestive of fluid secretion from the female gametophyte. 相似文献
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Expression patterns of an isoflavone reductase-like gene and its possible roles in secondary metabolism in Ginkgo biloba 总被引:1,自引:0,他引:1
Cheng Hua Li Linling Xu Feng Wang Yan Yuan Honghui Wu Conghua Wang Shaobing Liao Zhiqin Hua Juan Wang Yuping Cheng Shuiyuan Cao Fuliang 《Plant cell reports》2013,32(5):637-650
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Li Wang Jianguo Zhao Kaige Luo Jiawen Cui Qingsong He Xiao Xia Zhaogeng Lu Weixin Li Biao Jin 《Trees - Structure and Function》2016,30(5):1557-1567
Key message
High-throughput sequencing and subsequent analysis identified multiple miRNAs closely related to ovule, indicating that miRNAs are important in Ginkgo biloba ovule.Abstract
MicroRNAs (miRNAs) are small, noncoding, regulatory RNAs that play crucial regulatory roles in the process of plant growth and development. However, limited information regarding their functions in gymnosperm reproduction is available. Here, we used high-throughput sequencing combined with computational analysis to identify and characterize miRNAs from ovules of G. biloba, and identified 34 conserved miRNA families and 99 novel miRNAs. The precursor sequences of several of the conserved and novel miRNAs were further validated by RT-PCR and sequencing. Furthermore, we found that some target genes, e.g. MYB, homeodomain-leucine zipper (HD-ZIPIII) and auxin response factor (ARF), may be involved in ovule development, and that the significantly enriched pathways of some miRNA targets were related to plant–pathogen interactions and the biosynthesis of secondary metabolites. Twenty-six conserved miRNA families were found to be expressed in both leaves and ovules, while miRNA156, miRNA164, miRNA167, miRNA169, miRNA172 and miRNA390 were up-regulated in ovules. Thus, multiple miRNAs closely related to G. biloba ovule development were identified, resulting in a greater understanding of the important regulatory functions of miRNAs in plant ovules.6.
Key message
Extended antipodal life-span.Abstract
The female gametophyte of most flowering plants forms four cell types after cellularization, namely synergid cell, egg cell, central cell and antipodal cell. Of these, only the antipodal cells have no established functions, and it has been proposed that in many plants including Arabidopsis, the antipodal cells undergo programmed cell death during embryo sac maturation and prior to fertilization. Here, we examined the expression of female gametophyte-specific fluorescent reporters in mature embryo sacs of Arabidopsis, and in developing seeds shortly after fertilization. We observed expression of the fluorescence from the reporter genes in the three antipodal cells in the mature stage embryo sac, and continuing through the early syncytial endosperm stages. These observations suggest that rather than undergoing programmed cell death and degenerating at the mature stage of female gametophyte as previously supposed, the antipodal cells in Arabidopsis persist beyond fertilization, even when the other cell types are no longer present. The results support the concept that the Arabidopsis female gametophyte at maturity should be considered to be composed of seven cells and four cell types, rather than the previously prevailing view of four cells and three cell types. 相似文献7.
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Yuheng Yang Jing Zhao Huijun Xing Junyi Wang Kai Zhou Gangming Zhan Hongchang Zhang Zhensheng Kang 《Plant cell reports》2014,33(3):423-433
Key message
Japonica and indica have different non-host resistance (NHR) abilities to Puccinia striiformis f. sp. tritici ( Pst ), and hydrogen peroxide (H 2 O 2 ) has a positive function in NHR to japonica against Pst.Abstract
Non-host interactions between Puccinia striiformis f. sp. tritici (Pst) and two rice subspecies were characterized using 23 rice varieties, including 11 japonica and 12 indica. Results showed that the infected fungal structures were easily produced in the leaves of indica, whereas only several substomatal vesicles and primary infection hyphae were observed in the leaves of japonica. This result indicated that indica is less resistant or more susceptible to Pst than japonica. Hydrogen peroxide accumulated in the initial phase of japonica–Pst interaction but not in indica–Pst interaction. A set of reactive oxygen species (ROS)-related genes was also induced in response to Pst infection, suggesting that ROS activation is one of the major mechanisms of non-host resistance of rice to Pst. 相似文献10.
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Summary. The archegonium chamber in Ginkgo biloba L. is a pathway for spermatozoids swimming towards the archegonium for fertilization. The objective of this study was to
elucidate the mechanism of archegonium chamber formation. The terminal deoxynucleotidyl transferase-mediated dUTP nick end
labeling assay and DNA ladder demonstrated that the nucellar cell death, coordinated with the archegonium chamber formation,
was a process of programmed cell death. Cytochemical localization of Ca2+ in these nucellar cells was determined by means of in situ precipitation with potassium pyroantimonate and electron microscopic
visualization, in order to study the relation between Ca2+ and programmed cell death. The results showed an early uptake of the mitochondrial calcium particles in the nucellar cells
undergoing programmed cell death. Together with other dynamic changes in Ca2+ subcellular distribution, this indicates that Ca2+ may play a role in the regulation of mitochondria-mediated programmed events in the nucellar cells.
Correspondence and reprints: School of Pharmaceutical Sciences, Peking University, Beijing 100083, People’s Republic of China. 相似文献
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M. V. Darii A. R. Rakhimova V. N. Tashlitsky S. V. Kostyuk N. N. Veiko A. A. Ivanov A. L. Zhuze E. S. Gromova 《Molecular Biology》2013,47(2):259-266
Cancer cells are characterized by hypermethylation of the promoter regions of tumor suppressor genes. DNA methyltransferase inhibitors reactivate the genes, pointing to DNA methyltransferases as potential targets for anticancer therapy. Dimeric bisbenzimidazoles varying in the length of an oligomeric linker between two bisbenzimidazole residues (DB(n), where n is the number of methylene groups in the linker) were earlier shown to efficiently inhibit methylation of DNA duplexes by murine DNA methyltransferase Dnmt3a. Here, some of the compounds were tested for cytotoxicity, cell penetration, and effect on genomic DNA methylation in F-977 fetal lung fibroblasts and HeLa cervical cancer cells. Within the 0–60 μM concentration range, only DB(11) exerted a significant toxic effect on normal cells, whereas the effects of DB(n) on cancer cells were not significant. DB(1) and DB(3) slightly stimulated proliferation of HeLa and F-977 cells, respectively. DB(1) and DB(3) penetrated into the nuclei of HeLa and F-977 cells and accumulated predominantly in or near the nucleolus, while DB(11) was incapable of nuclear penetration. HeLa cells incubated with 26 μM DB(1) or DB(3) displayed a decrease in methylation of the 18S rRNA gene, which was in the regions of predominant accumulation of DB(1) and DB(3). The same DB(3) concentration exerted a similar effect on F-977 cells. However, the overall genomic DNA methylation level remained unchanged in both of the cell lines. The results indicated that DB(n)-type compounds can be used to demethylate certain genes and are thereby promising as potential anticancer agents. 相似文献
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Sompong Chankaew Takehisa Isemura Ken Naito Eri Ogiso-Tanaka Norihiko Tomooka Prakit Somta Akito Kaga Duncan A. Vaughan Peerasak Srinives 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(3):691-702
Key message
QTL mapping in F 2 population [ V. luteola × V. marina subsp. oblonga ] revealed that the salt tolerance in V. marina subsp. oblonga is controlled by a single major QTL.Abstract
The habitats of beach cowpea (Vigna marina) are sandy beaches in tropical and subtropical regions. As a species that grows closest to the sea, it has potential to be a gene source for breeding salt-tolerant crops. We reported here for the first time, quantitative trait loci (QTLs) mapping for salt tolerance in V. marina. A genetic linkage map was constructed from an F2 population of 120 plants derived from an interspecific cross between V. luteola and V. marina subsp. oblonga. The map comprised 150 SSR markers. The markers were clustered into 11 linkage groups spanning 777.6 cM in length with a mean distance between the adjacent markers of 5.59 cM. The F2:3 population was evaluated for salt tolerance under hydroponic conditions at the seedling and developmental stages. Segregation analysis indicated that salt tolerance in V. marina is controlled by a few genes. Multiple interval mapping consistently identified one major QTL which can explain about 50 % of phenotypic variance. The flanking markers may facilitate transfer of the salt tolerance allele from V. marina subsp. oblonga into related Vigna crops. The QTL for domestication-related traits from V. marina are also discussed. 相似文献15.
Michael A. Sundue 《Brittonia》2014,66(2):174-185
Mycopteris, a new genus of grammitid ferns, is described and combinations are made for the species that belong to it. Mycopteris is diagnosed by castaneous rhizome scales with turgid cells, usually pectinate laminae, blackish petioles and rachises, blackish pinna costae and veins, reddish setae, cretaceous hydathodes, glabrous sporangia, and the presence of Acrospermum ascomes. It is entirely neotropical, ranging from Mexico east into the West Indies and south to Bolivia. Mycopteris is one of two genera of grammitid ferns that are consistently associated with Acrospermum, an epibiotic ascomycete that produces black clavate fruiting bodies. Seventeen species of Mycopteris are recognized here, including one new species (M. longipilosa) and one elevated from the rank of variety to species (M. costaricensis). The following additional combinations are made here: M. alsopteris, M. amphidasyon, M. attenuatissima, M. cretata, M. grata, M. leucolepis, M. leucostica, M. longicaulis, M. pirrensis, M. praeceps, M. semihirsuta, M. steyermarkii, M. subtilis, M. taxifolia, and M. zeledoniana. Lectotypes are chosen for Ctenopteris leucosticta, Polypodium amphidasyon, and Polypodium pectinatum var. hispidum. For each accepted species, full synonymy and geographical range are provided. Taxonomic discussion is provided for species not widely recognized in previous treatments. 相似文献
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The following new taxa are recognized inArceuthobium: subgeneraArceuthobium andVaginata; sectionsVaginata, Campylopoda, andMinuta; seriesCampylopoda,Rubra, andStricta; speciesA. apachecum,A. californicum,A. guatemalense,A. hondurense, andA. pini; new formae spécialesA. abietinum f. sp.concoloris,A. abietinum f. sp.magnificae. New combinations:A. abietinum (Engelm.) Hawksworth & Wiens, andA. microcarpum (Engelm.) Hawksworth & Wiens. 相似文献
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Guizhen Zhang Yanhua Zhang Jianchun Qin Xiaoyan Qu Jinliang Liu Xiang Li Hongyu Pan 《Indian journal of microbiology》2013,53(2):175-180
The fungal endophyte Chaetomium globosum No.04 was isolated from the medicinal plant Ginkgo biloba. The crude extract of the fungus fermentation were active in the agar-diffusion tests against the phytopathogenic fungi Rhizopus stolonifer and Coniothyrium diplodiella. Further bioassay-guided chemical investigation led to the isolation and purification of six alkaloids and three non-targeted compounds from 50 L fermentation of this endophytic fungus and their structures were elucidated as chaetoglobosin A, C, D, E, G, R (1-6), ergosterol, allantoin and uracil, by means of spectroscopic analysis. Compounds 1-6 showed significant growth inhibitory activity against R. stolonifer and C. diplodiella at a concentration of 20 μg/disc. We present here, for the first time, the potent antifungal activity of chaetoglobosins from endophytic fungi against two important phytopathogenic fungi R. stolonifer and C. diplodiella. 相似文献
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Mariusz Jaremko Łukasz Jaremko Adam Mazur Maciej Makowski Marek Lisowski 《Amino acids》2013,45(4):865-875
Conformations of three pairs of dehydropeptides with the opposite configuration of the ΔPhe residue, Boc-Gly-ΔZ/EPhe-Phe-p-NA (Z- p -NA and E- p -NA), Boc-Gly-ΔZ/EPhe-Phe-OMe (Z-OMe and E-OMe), and Boc-Gly-ΔZ/EPhe-Phe-OH (Z-OH and E-OH) were compared on the basis of CD and NMR studies in MeOH, TFE, and DMSO. The CD results were used as the additional input data for the NMR-based calculations of the detailed solution conformations of the peptides. It was found that Z- p -NA, E- p -NA, Z-OMe, and Z-OH adopt the β-turn conformations and E-OMe and E-OH are unordered. There are two overlapping type III β-turns in Z- p -NA, type II’ β-turn in E- p -NA, and type II β-turn in Z-OMe and Z-OH. The results obtained indicate that in the case of methyl esters and peptides with a free carboxyl group, ΔZPhe is a much stronger inducer of ordered conformations than ΔEPhe. It was also found that temperature coefficients of the amide protons are not reliable indicators of intramolecular hydrogen bonds donors in small peptides. 相似文献
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Zhang Ruiqi Zhang Mingyi Wang Xiue Chen Peidu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(3):523-533