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1.
The seaweed Laminaria japonica (Phaeophyceae) has a two-generation life cycle consisting of haploid gametophytes and diploid sporophytes. Female and/or male gametophytes were transformed using particle bombardment and the histological LacZ assay was performed on sporophytes generated by either parthenogenesis or inbreeding. Female gametophyte-targeted transformation resulted in similar lower efficiencies in both parthenogenetic and zygotic sporophytes, and only a chimeric expression pattern was observed. Male gametophyte-targeted transformation led to a higher efficiency, with 3.5% of the zygotic sporophytes stained completely blue (all-blue), implying the integration of lacZ at the one-cell stage. Polymerase chain reaction analysis using primers specific for a lacZ-vector juncture fragment and subsequent blotting indicated the presence of the introduced gene in the sporophytes. The method reported here has a potential for seaweed transformation using spore-based bombardment followed by the developmental process.Abbreviations DPR Detected positive rate - ER Expression rateCommunicated by F. Sato 相似文献
2.
Mazzaella laminarioides has consistently been reported as a typical coalescent/clump species with a triphasic life history of the Polysiphonia-type in which the haploid gametophyte is the predominant phase with respect to the diploid sporophyte. Preliminary observations
of intertidal populations revealed that, in some instances, cystocarpic and tetrasporic fronds emerged from the same clump
(G-T clumps), implying a coalescent process of haploid and diploid thalli by fusion of their corresponding adjacent basal
holdfasts. Population surveys at three sites in Coliumo Bay, central Chile, were carried out to characterize frond demography
as well as to asses the frequency of gametophyte-tetrasporophyte (G-T) coalescence. Visual and resorcinol methods were employed
to determine the phases of the fronds collected over central transects of 15 randomly sampled clumps. Coalescence of G-T clumps
was infrequent, with gametophytes dominating over tetrasporophyte thalli. 相似文献
3.
Haploid sporophytes of Osmunda claytoniana (2n = x = 22) were apogamously produced from calli when cultivated on a hormone-free medium. Flow cytometric analysis showed that
ploidy chimeras were spontaneously produced in a haploid sporophyte of O. claytoniana and those of O. japonica that were obtained in the previous study. In the haploid sporophyte of O. claytoniana, a diploid pinnule and a partially diploid terminal segment were produced in a haploid pinna. In O. japonica, a haploid sporophyte yielded a diploid pinna in a haploid frond, and another haploid sporophyte yielded a diploid pinnule
in a haploid pinna. Diploid chimeras were large in size and could be readily distinguished from other haploid parts of the
fronds. It is likely that the chimeras were produced clonally from a single diploid cell that established chromosome doubling. 相似文献
4.
The life-cycle of Scinaia interrupta (A.P. de Candolle) M. J. Wynne was investigated in vitro using four irradiance regimes: 4, 8, 12 and 16 μmol photons m−2 s−1. A triphasic heteromorphic life-cycle was observed. Carpospores released by cystocarps of gametophytes collected in the field
developed into filamentous tetrasporophytes, which produced tetrahedral tetrasporangia. Tetrasporangial development was accelerated
under higher irradiance levels. Tetraspores germinated into filamentous protonemal gametophytes, initially identical to the
tetrasporophyte. Filamentous gametophytes developed apical utricles and gave rise directly to the fleshy gametophyte. Further
development of the fleshy gametophyte was not observed at the lowest irradiance regime (4 μmol photons m−2 s−1). The present study reports for the first time the influence of the irradiance regime on the initial tetrasporangial development
and in the development of the fleshy gametophyte, and reinforces the importance of light intensity on Scinaia life-cycle. Production of apical utricles by the filamentous gametophyte is newly reported for the genus. 相似文献
5.
Quan Sheng Zhang Shan Cun Qu Yi Zhou Cong Shi Ju Luo Xue Xi Tang 《Journal of applied phycology》2008,20(2):205-211
In anticipation of the application of a new sporeling-raising method using gametophyte clones to Laminaria commercial cultivation in China, techniques of mass culture and gametogenesis induction of L. japonica gametophyte clones were developed, as a mass of fertile gametophytes is a prerequisite for sporeling-raising with the new
method. Gametophyte clones which were subjected to fed-batch culture exhibited a classical logistic growth curve. Growth rates
decreased gradually after 2 months of culture, and were negatively correlated to cell density. UNOVA also showed that only
cell density has a significant effect on the growth of gametophyte clones under the experimental conditions. Based on the
dynamics models revealed, a culture strategy only directed at the control of cell density was adopted. By this strategy, a
total of 36 kg wet weight from an initial weight of 0.75 kg was achieved after 3 months culture in 100 20-L bottles. The final
average density reached 24 g L−1. For the subsequent gametogenesis induction, amplificatory male and female gametophyte clones were cut, mixed and cultured
in bottles under the same conditions used in amplification except for a change of photoperiod from continuous irradiance to
10 h light: 14 h dark cycle. Egg discharge occurred 10 days after the mixed culture and increased gradually with the culture
duration. Most gametophytes gave rise to sporophytes 20 days after induction. Large-scale culture of gametophyte clones and
gametogenesis induction for commercial cultivation in 2003–2005 have been conducted successfully. 相似文献
6.
7.
Daniel A. Coury Changqing Zhang Ara Ko Megan I. Skaggs Cory A. Christensen Gary N. Drews Kenneth A. Feldmann Ramin Yadegari 《Sexual plant reproduction》2007,20(2):87-97
The female and male gametophytes are critical components of the angiosperm life cycle and are essential for the reproductive
process. The gametophytes share many essential cellular processes with each other and with the sporophyte generation. As a
consequence, these processes can only be analyzed genetically in the gametophyte generation. Here, we report the characterization
of the gametophytic factor 1 (gfa1) mutant. The gfa1 mutation exhibits reduced transmission through both the female and male gametophytes. Reduced transmission through the female
gametophyte is due to an effect on female gametophyte development. By contrast, development of the pollen grain is not affected
in gfa1; rather, reduced transmission is likely due to an effect on pollen tube growth. We have identified multiple T-DNA-insertion
alleles of gfa1 in a gene encoding a protein with high similarity to Snu114/U5-116 kD proteins from yeast and animals required for normal
pre-mRNA splicing. Consistent with its predicted function, the GFA1 gene (At1g06220) is expressed throughout the plant. Together, these data suggest that GFA1 functions in mRNA splicing during
the plant life cycle.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Jose María Gabriel y Galán 《Biologia》2011,66(1):50-54
The gametophyte of Argyroschosma nivea was studied, mainly focusing in its morphological development, and in the apogamous production of sporophytes. Some observations
on the spores were also made. As far as it is known, this is the second species of the genus whose gametophytes are studied.
The germination pattern followed the Vittaria type. The subsequent developmental processes followed the Ceratopteris type. Some of the gametophytes reached an adult stage with a cordate, symmetric shape, but most of them developed as irregular,
lobed prothalli. The sporophyte emerged from the anterior part of the prothallus, without formation of gametangia. First,
a cell became active and originated a proliferating area of small cells. From this area, long glandular hairs were formed
followed by a projected conical cluster of cells. The cluster elongated into a sporophytic structure and its apex became progressively
spatulate and finally trilobulate, with marginal, glandular hairs, stomata and tracheids continuously produced. This sporophyte
secreted granules of white farina from its beginnings. The production of farina in the sporophyte but not in the gametophyte
could help to support the idea of the segregation of this species from its traditional location in Notholaena to Argyrochosma, as farinose gametophytes seem to be a synapomorphy of the notholenoids, group that includes Notholaena but not Argyroschoma. 相似文献
9.
Arabidopsis ACT2 represents an ancient class of vegetative plant actins and is strongly and constitutively expressed in almost all Arabidopsis sporophyte vegetative tissues. Using the beta glucuronidase report system, the studies showed that ACT2 5′ regulatory region was significantly more active than CaMV 35S promoter in Arabidopsis seedlings and gametophyte vegetative tissues of Physcomitrella patens. Its activity was also observed in rice and maize seedlings. Thus, the ACT2 5′ regulatory region could potentially serve as a strong regulator to express a transgene in divergent plant species. ACT2 5′ regulatory region contained 15 conserved sequence elements, an ancient intron in its 5′ un-translated region (5′ UTR),
and a purine-rich stretch followed by a pyrimidine-rich stretch (PuPy). Mutagenesis and deletion analysis illustrated that
some of the conserved sequence elements and the region containing PuPy sequences played regulatory roles in Arabidopsis. Interestingly, mutation of the conserved elements did not lead a dramatic change in the activity of ACT2 5′ regulatory region. The ancient intron in ACT2 5′ UTR was required for its strong expression in both Arabidopsis and P. patens, but did not fully function as a canonical intron. Thus, it was likely that some of the conserved sequence elements and gene
structures had been preserved in ACT2 5′ regulatory region over the course of land plant evolution partly due to their functional importance. The studies provided
additional evidences that identification of evolutionarily conserved features in non-coding region might be used as an efficient
strategy to predict gene regulatory elements. 相似文献
10.
Honggen Zhang Lijia Zhang Hua Si Yongshen Ge Guohua Liang Minghong Gu Shuzhu Tang 《Molecular breeding : new strategies in plant improvement》2016,36(7):102
Three-line japonica hybrids have been developed mainly on Chinsurah Boro II (BT)-type cytoplasmic male sterile (CMS) lines of Oryza sativa L., but the unstable sterility of some BT-type CMS lines, and the threat of genetic vulnerability when using a single cytoplasm source, have inhibited their use in rice cultivation. Previously, the sterility of Honglian (HL)-type japonica CMS lines derived from common red-awned wild rice (Oryza rufipogon) has been proven to be more stable than that of BT-type japonica CMS lines. Here, we genetically characterized HL-type japonica CMS lines and the restorer-of-fertility (Rf) gene for breeding HL-type japonica hybrids. HL-type japonica CMS lines displayed stained abortive pollen grains, unlike HL-type indica CMS lines. The BT-type japonica restorer lines, which contain Rf, had different capabilities to restore HL-LiuqianxinA (HL-LqxA), an HL-type japonica CMS line, and the restorers for the HL-type japonica CMS lines could be selected from the preexisting BT-type japonica restorers in rice production. A genetic analysis showed that the restoration of normal fertility to HL-LqxA was controlled by a major gene and was affected by minor effector genes and/or modifiers. The major Rf in SiR2982, a BT-type japonica restorer, was mapped to a ~100-kb physical region on chromosome 10, and was demonstrated to be Rf5 (Rf1a) by sequencing. Furthermore, Rf5 partially restored fertility and had a dosage effect on HL-type japonica CMS lines. These results will be helpful for the development of HL-type japonica hybrids. 相似文献
11.
Development of heavily asymmetric cordate gametophytes of Anemia phyllitidis (Anemiaceae), one of the schizaeoid ferns, was examined using a sequential observation technique; epi-illuminated light micrographs
of the same growing gametophytes were taken approximately every 24 h. The apical cell-like wedge-shaped cell was produced
once from the terminal cell of a germ filament, but it stopped dividing soon after production of one or two derivative cells.
Without a functional apical cell, the gametophyte developed by intercalary growth until the early stage of wing formation,
and then the multicellular (pluricellular) meristem arose from the lower lateral side of the gametophyte. This was in sharp
contrast to the observation that the multicellular meristem forms in place of the apical cell in typical cordate gametophytes.
Loss of the functional apical cell probably caused a site-shift in the multicellular meristem of the Anemia phyllitidis gametophyte during evolution from apical to lateral. The results suggest that apical cell-based and multicellular meristems
are primarily independent of each other. The multicellular meristem produced cells equally in the distal and proximal directions
to form wings in both directions but proximally produced cells divided much less frequently. As a result, a heavily asymmetric
gametophyte was formed. 相似文献
12.
Wang J Raman H Zhou M Ryan PR Delhaize E Hebb DM Coombes N Mendham N 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(2):265-276
Aluminium (Al) tolerance in barley is conditioned by the Alp locus on the long arm of chromosome 4H, which is associated with Al-activated release of citrate from roots. We developed
a high-resolution map of the Alp locus using 132 doubled haploid (DH) lines from a cross between Dayton (Al-tolerant) and Zhepi 2 (Al-sensitive) and 2,070
F2 individuals from a cross between Dayton and Gairdner (Al-sensitive). The Al-activated efflux of citrate from the root apices
of Al-tolerant Dayton was 10-fold greater than from the Al-sensitive parents Zhepi 2 and Gairdner. A suite of markers (ABG715,
Bmag353, GBM1071, GWM165, HvMATE and HvGABP) exhibited complete linkage with the Alp locus in the DH population accounting 72% of the variation for Al tolerance evaluated as relative root elongation. These
markers were used to map this genomic region in the Dayton/Gairdner population in more detail. Flanking markers HvGABP and
ABG715 delineated the Alp locus to a 0.2 cM interval. Since the HvMATE marker was not polymorphic in the Dayton/Gairdner population we instead investigated
the expression of the HvMATE gene. Relative expression of the HvMATE gene was 30-fold greater in Dayton than Gardiner. Furthermore, HvMATE expression in the F2:3 families tested, including all the informative recombinant lines identified between HvGABP and ABG715 was significantly correlated
with Al tolerance and Al-activated citrate efflux. These results identify HvMATE, a gene encoding a multidrug and toxic compound extrusion protein, as a candidate controlling Al tolerance in barley. 相似文献
13.
Attacin, a 20 kDa antibacterial peptide, plays an important role in immunity. To understand this gene better, gene cloning,
expression and biological activity detection of Attacin A was carried out in present study. The full-length open reading frame
(ORF) coding for Attacin A gene was generated using RT-PCR which takes total RNA extracted from Drosophila as the template. The gene was inserted directionally into the prokaryotic expression vector pET-32a (+). The resulting recombinant
plasmid was transformed into E. coli
Rosetta. SDS–PAGE was carried out to detect the expression product which was induced by IPTG. The antimicrobial activity and hemolysis
activity were tested in vitro after purification. Agarose gel electrophoresis indicated that the complete ORF of Attacin A
gene has been cloned successfully from Drosophila stimulated by E. coli which includes 666 bp and encodes 221 AA. The gene encoding mature Attacin A protein was amplified by PCR from the recombinant
plasmid containing Attacin A, which includes 570 bp in all. SDS–PAGE analysis demonstrated that the fusion protein expressed
was approximately 39.2 kDa. Biological activities detection showed that this peptide exhibited certain antibacterial activity
to several G− bacteria, as well as minor hemolysis activity for porcine red blood cells. In conclusion, Attacin A gene was
cloned and expressed successfully. It was the basis for further study of Attacin. 相似文献
14.
15.
A d -lactonohydrolase gene of about 1.1 kb was cloned from Fusarium moniliforme. The ORF sequence predicted a protein of 382 amino acids with a molecular mass of about 40 kDa. An expression plasmid carrying the gene under the control of the triose phosphate isomerase gene promotor was introduced into Saccharomyces cerevisiae, and the d -lactonohydrolase gene was successfully expressed in the recombinant strains.Revisions requested 10 September 2004; Revisions received 15 October 2004The nucleotide sequence data reported in this paper has been assigned accession number AY728018 in the GeneBank database. 相似文献
16.
The mutant dark-germinating 1 (dkg1) of the fern Ceratopteris richardii was originally characterized by two phenotypes, germination in the dark and inhibition of germination by light. In this work, we examined whether other phenotypes are present in the gametophytic generation of the dkg1 mutant. Although dkg1 prothalli grown in darkness were elongated as in the case of the wild type, some developmental processes were found to proceed even in complete darkness: (1) the apical and subapical zones developed largely by forming a lateral meristem; (2) asymmetric cell division for rhizoid differentiation occurred in the subapical elongation zone; (3) an archegonium was formed in the proximity of the meristem; and (4) chloroplast relocation could occur without de novo protein synthesis. Furthermore, these processes were shown to be under the control of phytochrome in the wild-type gametophytes on the basis of red/far-red reversibility. These results indicate that the DKG1 gene is pleiotropic and is involved in several phytochrome-mediated responses in the gametophyte development of C. richardii. 相似文献
17.
The mycorrhizal fungi in the roots of achlorophyllous Sciaphila japonica and S. tosaensis (Triuridaceae) were identified by molecular methods. The habitats of S. japonica were in a tree plantation of Japanese cypress, Chamaecyparis obtusa, and bamboo forests, and those of S. tosaensis were in a camellia forest and a bamboo forest. In the root cortical cells of both plants, aseptate hyphal coils were observed,
which suggested the Paris-type arbuscular mycorrhiza (AM). A phylogenetic analysis based on a partial sequence of an AM fungal nuclear small subunit
ribosomal RNA gene showed that the fungal DNA sequences of S. japonica were separated into three closely related clades. Those of S. tosaensis were separated into two clades, which were also closely related to each other. The AM fungi of S. japonica and S. tosaensis were completely separated in the phylogenetic tree even among those found in the same habitat, which suggests the high specificities
in the plant-fungal partnerships. All the detected AM fungi in these plants belonged to Glomus-group A. Even though the habitats are in quite common environments, both plant species are known as endangered species in
Japan. Such a definite specificity in AM symbioses seems to restrict the distribution of the myco-heterotrophic plants. 相似文献
18.
Elsa Pimienta Julio C Ayala Caridad Rodríguez Astrid Ramos Lieve Van Mellaert Carlos Vallín Jozef Anné 《Microbial cell factories》2007,6(1):20
Background
Streptokinase (SK) is a potent plasminogen activator with widespread clinical use as a thrombolytic agent. It is naturally secreted by several strains of beta-haemolytic streptococci. The low yields obtained in SK production, lack of developed gene transfer methodology and the pathogenesis of its natural host have been the principal reasons to search for a recombinant source for this important therapeutic protein. We report here the expression and secretion of SK by the Gram-positive bacterium Streptomyces lividans. The structural gene encoding SK was fused to the Streptomyces venezuelae CBS762.70 subtilisin inhibitor (vsi) signal sequence or to the Streptomyces lividans xylanase C (xlnC) signal sequence. The native Vsi protein is translocated via the Sec pathway while the native XlnC protein uses the twin-arginine translocation (Tat) pathway. 相似文献19.
The six most toxic Pakistani isolates of Bacillus thuringiensis (SBS Bt-23, 29, 34, 37, 45 and 47), which were previously characterized for their toxicity against larvae of mosquito, Anopheles stephensi, and the presence of cry4 gene, were used for cry11 (cry4D) gene amplification. A 1.9-kb DNA fragment of cry11 gene was PCR-amplified, cloned in expression vector pT7-7, and then used for transformation of E. coli BL21C. The optimum expression was obtained with 1 mM IPTG at 37°C for 3 h. This gene showed different percentage homologies
at protein level with scattered mutations in the toxic region. Biotoxicity assay of recombinant protein showed that Cry11
of SBS Bt 45 (DAB Bt 5) was the most toxic protein against third instar larvae of mosquito, A. stephensi, and has potentiality of a bioinsecticide against mosquitoes. 相似文献
20.
A synthetic chimeric gene SbtCryIII(A) encoding the insecticidal protein btCryIII(A), was transformed into Pinus armandii embryos and embryogenic calli using Agrobacterium tumefaciens. Polymerase chain reaction and genomic DNA Southern blot analysis showed that the SbtCryIII(A) gene was integrated into the genome of transgenic Pinus armandii plants, and Northern blot analysis indicated that the SbtCryIII(A) gene was transcribed. 相似文献