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1.
Post-pollination hybridization barriers in <Emphasis Type="Italic">Nicotiana</Emphasis> section <Emphasis Type="Italic">Alatae</Emphasis> 总被引:1,自引:1,他引:0
Christopher B. Lee Lawrence E. Page Bruce A. McClure Timothy P. Holtsford 《Sexual plant reproduction》2008,21(3):183-195
Nicotiana section Alatae contains eight species with variable flower sizes and morphologies. Section members readily hybridize in the glasshouse,
but no hybrids have been observed in natural sympatric and parapatric populations. To investigate interspecific crossing relationships
with respect to mechanisms preventing hybridization, all members of section Alatae were intercrossed in a complete diallel. We found positive correlation between the pistil length of the pollen donor and
interspecific seed set relative to the conspecific cross. Pollen tube growth rate and pollen donor pistil length were positively
correlated as well. Furthermore, pollen from short-pistil members of section Alatae could only grow a maximum distance proportional to, but greater than, their own pistil lengths. Our results show that pollen
tube growth capacity (i.e., rate and distance), provides a hybridization barrier in long-pistil species × short-pistil species
crosses. We also found another hybridization barrier not specifically related to pollen tube growth capacity in short-pistil
species × long-pistil species. Taken together, these barriers can generally be described by a ‘pistil-length mismatch’ rule;
in section Alatae, pollen has the most success fertilizing ovules from species with pistil lengths similar to their own. This rule could contribute
to hybridization barriers in Section Alatae because the species display dramatically different pistil lengths.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Many invasive alien plants occur in large populations with abundant flowers which are highly attractive to pollinators, and
thus might affect pollination of co-occurring native species. This study focuses on the invasive Heracleum mantegazzianum and distance-dependent effects on pollination of Mimulus guttatus in abandoned grassland over 2 years. First, we examined pollinator abundance in yellow traps at 0, 10, 30 and 60–200 m from
H. mantegazzianum. We then placed M. guttatus plants at the same distances to monitor effects of the invasive species on pollinator visitation and seed set of neighbouring
plants. Finally, we conducted a garden experiment to test if deposition of H. mantegazzianum pollen reduces seed set in M. guttatus. No distance effect was found for the number of bumblebees in traps, although the invasive species attracted a diverse assemblage
of insects, and visitation of M. guttatus was enhanced close to H. mantegazzianum. This positive effect was not reflected by seed set of M. guttatus, and heterospecific pollen decreased seed set in these plants. Overall there is little evidence for negative effects of the
invasive species on pollination of neighbouring plants, and flower visitation even increases close to the invaded patches.
The functional role of the invader and suitable control strategies need further clarification, since removal of H. mantegazzianum may actually damage local pollinator populations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
4.
Lim GT Wang GP Hemming MN McGrath DJ Jones DA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,118(1):57-75
The tomato I-3 gene introgressed from the Lycopersicon pennellii accession LA716 confers resistance to race 3 of the fusarium wilt pathogen Fusarium oxysporum f. sp. lycopersici. We have improved the high-resolution map of the I-3 region of tomato chromosome 7 with the development and mapping of 31 new PCR-based markers. Recombinants recovered from L. esculentum cv. M82 × IL7-2 F2 and (IL7-2 × IL7-4) × M82 TC1F2 mapping populations, together with recombinants recovered from a previous
M82 × IL7-3 F2 mapping population, were used to position these markers. A significantly higher recombination frequency was
observed in the (IL7-2 × IL7-4) × M82 TC1F2 mapping population based on a reconstituted L. pennellii chromosome 7 compared to the other two mapping populations based on smaller segments of L. pennellii chromosome 7. A BAC contig consisting of L. esculentum cv. Heinz 1706 BACs covering the I-3 region has also been established. The new high-resolution map places the I-3 gene within a 0.38 cM interval between the molecular markers RGA332 and bP23/gPT with an estimated physical size of 50–60 kb.
The I-3 region was found to display almost continuous microsynteny with grape chromosome 12 but interspersed microsynteny with Arabidopsis thaliana chromosomes 1,
2 and 3. An S-receptor-like kinase gene family present in the I-3 region of tomato chromosome 7 was found to be present in the microsyntenous region of grape chromosome 12 but was absent altogether from the A. thaliana genome.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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6.
Xiaoyan Dai Jingjuan Yu Jinxia Ma Guangming Ao Qian Zhao 《Plant Growth Regulation》2007,52(3):229-239
We previously identified a 0.7 Kb cDNA fragment of Zm401, a novel pollen-specific gene in maize (Zea mays). However, little information is known about the function of Zm401 in pollen development. The full-length of Zm401 cDNA was amplified by 5′ RACE and 3′ RACE and both sequence analysis and in vitro translation of Zm401 showed that it belonged to an mRNA-like non-coding gene. To analyze its possible biological roles in pollen development,
the Zm401 cDNA was overexpressed in transgenic maize under the control of a pollen specific promoter Zm13 or a CaMV 35S promoter. RT-PCR and RNA gel blot analysis indicated that the expression level of Zm401 in leaves and anthers of transgenic plants was much higher than that of non-transformants. Compared with the non-transformed
maize, transgenic maize showed distinct phenotypes, such as abnormal tassels and degenerate anthers. The histological observation
showed that the development of pollen grains and anthers in transgenic plants were abnormal. These abnormalities include delayed
degradation of tapetum, asynchronous fusion of pollen sacs, and aborted pollen grain development. Furthermore, the pollen
viability in six transgenic plants ranged from 1.24% to 6.63%. The reduced pollen viability cosegregated with the transgene
in a selfed progeny. These results suggest that Zm401 is involved in the regulation of pollen development. This article demonstrated Zm401, as a non-coding RNA, plays an essential role in pollen development.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
Phosphoinositide-specific phospholipase C (PI-PLC) is an important enzyme, which is a key player involved in eukaryotic signal
transduction pathways. In plants, it plays a key role in growth and development as well as environmental stress. However,
little is known about its roles in signal transduction during sexual reproduction process. In this study, we cloned and characterized
a gene of full-length PI-PLC from ovules of Torenia fournieri, designated as TfPLC1. It was 2,171 bp in length, including an open reading frame encoding a polypeptide of 583 amino acids with molecular mass
of 66.02 kDa. The amino acid sequence deduced from the cDNA sequence shows 40–76% similarity to other plant PI-PLCs and contains
the characteristic X, Y and C2 domains. Northern blot analysis demonstrated it was predominantly expressed in ovules and flowers.
Furthermore, TfPLC1 promoter::GUS transgenic analysis indicated it specifically expressed in ovule, stigma and mature pollen grain. Immunohistochemical
staining showed that, in mature stigma, TfPLC1 protein was principally localized in the cells of stigmatic receptive surface.
Together, our data suggest that TfPLC1 may play an important role in plant sexual reproduction.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
A centromeric DNA sequence colocalized with a centromere-specific histone H3 in tobacco 总被引:1,自引:0,他引:1
Centromeres play an important role in segregating chromosomes into daughter cells, and centromeric DNA assembles specific
proteins to form a complex referred to as the kinetochore. Among these proteins, centromere-specific histone H3 (CENH3) is
one of the most characterized and found to be located only on active centromeres. We isolated four different CENH3-coding
complementary DNAs (cDNAs), two from Nicotiana tabaccum and one each from the ancestral diploid species, Nicotiana sylvestris and Nicotiana tomentosiformis and raised an antibody against N-terminal amino acid sequences deduced from the cDNAs. Immunostaining with the antibody revealed
the preferential centromere localization, indicating that the cDNAs cloned in this study encode authentic tobacco CENH3. A
tobacco centromeric DNA sequence (Nt2-7) was also identified by chromatin immunoprecipitation cloning using the antibody.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Maja Andri? Julieta Massaferro Ueli Eicher Brigitta Ammann Markus Christian Leuenberger Andrej Martin?i? Elena Marinova Anton Brancelj 《Hydrobiologia》2009,631(1):121-141
This study investigates the palaeoecological record (δ18O, δ13C, pollen, plant macrofossils, chironomids and cladocera) at Lake Bled (Slovenia) sedimentary core to better understand the
response of terrestrial and aquatic ecosystems to Late-glacial climatic fluctuations. The multi-proxy record suggests that
in the Oldest Dryas, the landscape around Lake Bled was rather open, presumably because of the cold and dry climate, with
a trend towards wetter conditions, as suggested by an increase in tree pollen as well as chironomid and cladocera faunas typical
for well-oxygenated water. Climatic warming at the beginning of the Late-glacial Interstadial at ca. 14,800 cal yr BP is suggested
by an increase in the δ18O value, the appearance of Betula and Larix pollen and macrofossils, and a warmth-adapted chironomid fauna. With further warming at ca. 13,800 cal yr BP, broad-leaved
tree taxa (Quercus, Tilia, Ulmus), Artemisia, and Picea increase, whereas chironomid data (Cricotopus B) suggest lowering of lake levels. After 12,800 cal yr BP (and throughout the Younger Dryas), the climate was colder and drier,
as indicated by lower δ18O values, decline of trees, increase of microscopic charcoal, xerophytes and littoral chironomids. A warmer climate, together
with the spread of broad-leaved tree taxa and a deeper, more productive lake, mark the onset of the Late-glacial/Holocene
transition. These results suggest that terrestrial and aquatic ecosystems at Lake Bled were very dynamic and sensitive to
Late-glacial climatic fluctuations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users.
Guest editors: K. Buczkó, J. Korponai, J. Padisák & S. W. Starratt
Palaeolimnological Proxies as Tools of Environmental Reconstruction in Fresh Water 相似文献
10.
In the present report, we described the effects of indole-3-acetic acid (IAA), zeatin (ZT), gibberellin (GA3), and abscisic acid (ABA) on in vitro pollen germination and pollen tube growth in Torenia fournieri L. The results showed that IAA and GA3 stimulated in vitro pollen tube growth, ABA inhibited pollen tube growth, and ZT had no significant effect on the process.
The stimulating effect of exogenous IAA was particularly distinct, and led to synchronous growth of straighter and more slender
pollen tubes compared with the controls. However, no significant changes were found in the germination of the treated pollen.
The auxin efflux inhibitor, 10 μM 1-N-naphthylphthalamic acid (NPA), was also found to stimulate pollen tube growth. We measured the content of hormones (free
IAA, ZT, GA3, and ABA) in the stigmas and styles before and after pollination. The hormone contents of stigmas measured 0.5 h after pollination
(0.5 HAP) showed that ABA content decreased, whereas the content of IAA, ZT, or GA3 did not change significantly. The hormone level in pollinated styles (4 HAP) when pollen tubes had grown into the middle
part of style was characterized by an increase in free IAA and GA3 and a decrease in ABA, which was in agreement with the results that IAA and GA3 promoted but ABA inhibited pollen tube growth in vitro. Furthermore, the change of IAA level in styles was most notable, which
was accordant to the fact that auxin stimulated significantly pollen tube growth in vitro. Using immunoenzyme and immunogold
labeling techniques and an anti-IAA monoclonal antibody, we confirmed that free IAA was present throughout style tissues,
and distributed in the nucleus and cytoplasm of style cells. All these results suggested that hormones, especially IAA, play
important roles in pollen tube growth of T. fournieri.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
Yongbiao Xue Yijing Zhang Qiuying Yang Qun Li Zhukuan Cheng Hugh G. Dickinson 《Plant molecular biology》2009,70(5):499-509
Self-incompatibility (SI), an important barrier to inbreeding in flowering plants, is controlled in many species by a single
polymorphic S-locus. In the Solanaceae, two tightly linked S-locus genes, S-RNase and SLF (S-locus F-box)/SFB (S-haplotype-specific F-box), control SI expression in pistil and pollen, respectively. The pollen S-determinant appears to function to inhibit all but self S-RNase in the Solanaceae, but its genetic function in the closely-related
Plantaginaceae remains equivocal. We have employed transposon mutagenesis in a member of the Plantaginaceae (Antirrhinum) to generate a pollen-part SI-breakdown mutant Pma1 (Pollen-part mutation in Antirrhinum1). Molecular genetic analyses showed that an extra telocentric chromosome containing AhSLF-S
1
is present in its self-compatible but not in its SI progeny. Furthermore, analysis of the effects of selection revealed positive
selection acting on both SLFs and SFBs, but with a stronger purifying selection on SLFs. Taken together, our results suggest an inhibitor role of the pollen S in the Plantaginaceae (as represented by Antirrhinum), similar to that found in the Solanaceae. The implication of these findings is discussed in the context of S-locus evolution in flowering plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Yongbiao Xue, Yijing Zhang, and Qiuying Yang contributed equally to this work. 相似文献
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13.
Raquel Garcia Petra Fousková Lurdes Gano António Paulo Paula Campello Éva Tóth Isabel Santos 《Journal of biological inorganic chemistry》2009,14(2):261-271
The novel DOTA-like chelator 1,4,7,10-tetraazacyclododecane-1-{4-[(3-chloro-4-fluorophenyl)amino]quinazoline-6-yl}propionamide-4,7,10-triacetic
acid (H3L) was synthesised by alkylation of 1,4,7,10-tetraazacyclododecane-1,4,7-tris(t-butyl acetate) with N-{4-[(3-chloro-4-fluorophenyl)amino]quinazoline-6-yl}-3-bromopropionamide, followed by hydrolysis of the ester groups with
trifluoracetic acid. H3L has been fully characterised by multinuclear NMR spectroscopy, mass spectrometry and high-performance liquid chromatography
(HPLC). Five protonation constants, log K
Hi
, of H3L were determined by potentiometry and UV–vis spectrophotometry and the values found are 10.47, 9.18, 5.24, 4.00 and 2.23.
These methods, complemented with variable-pH 71Ga NMR studies, allowed us to ascertain the stability constant of the Ga(III) complex of L. GaL has a remarkably high thermodynamic
stability constant (log K
ML = 24.5). The radioactive complex 67GaL was prepared in high yield and high radiochemical purity. Its HPLC chromatogram is identical to that obtained for the
GaL complex prepared at the macroscopic level. At pH 7.4, 67GaL has an overall neutral charge, is highly hydrophilic (log D = −1.02 ± 0.03) and presents high in vitro stability in physiological media and in the presence of an excess of diethylenetriaminepentaethanoic
acid . In vitro studies indicated that H3L and GaL do not inhibit the cell growth of epidermal growth factor receptor expressing cell lines, such as A431 cervical
carcinoma cells, a result which agrees with the very low cell internalisation found for 67GaL in the same cell line. Biodistribution studies in mice indicated high in vivo stability for 67GaL, a high total excretion rate and a relatively slow blood clearance, in full accordance with its hydrophilic character
and the relatively important protein binding.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
High temperature exposure did not affect induced 2n pollen viability in Populus 总被引:1,自引:0,他引:1
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Mengdi Tian Yuan Zhang Yan Liu Xiangyang Kang Pingdong Zhang 《Plant, cell & environment》2018,41(6):1383-1393
High temperature exposure is widely used as a physical mutagenic agent to induce 2n gametes in Populus. However, whether high temperature exposure affects induced 2n pollen viability remains unknown. To clarify whether high temperature exposure affected the induced 2n pollen viability, 2n pollen induced by 38 and 41 °C temperatures, pollen morphology, 2n pollen germination in vitro, and crossing induced 2n pollen with normal gametes to produce a triploid was, based on observations of meiosis, conducted in Populus canescens. We found that the dominant meiotic stages (F = 56.6, p < .001) and the treatment duration (F = 21.4, p < .001) significantly affected the occurrence rate of induced 2n pollen. A significant decrease in pollen production and an increase in aborted pollen were observed (p < .001). High temperature sometimes affected in ectexine deposition and some narrow furrows were also analysed via details of ectexine structure. However, no significant difference in 2n pollen germination rate was observed between natural 2n pollen (26.7%) and high‐temperature‐induced 2n pollen (26.2%), and 42 triploids were created by crossing high‐temperature‐induced 2n pollen, suggesting that 38 and 41 °C temperatures exposure will not result in dysfunctional induced 2n pollen. 相似文献
15.
Wei‐Han Hsu Tsung‐Jen Yeh Kai‐Yu Huang Jen‐Ying Li Hsing‐Yu Chen Chang‐Hsien Yang 《The Plant journal : for cell and molecular biology》2014,77(1):1-15
Arabidopsis AGL13 is a member of the AGL6 clade of the MADS box gene family. GUS activity was specifically detected from the initiation to maturation of both pollen and ovules in AGL13:GUS Arabidopsis. The sterility of the flower with defective pollen and ovules was found in AGL13 RNAi knockdown and AGL13 + SRDX dominant‐negative mutants. These results indicate that AGL13 acts as an activator in regulation of early initiation and further development of pollen and ovules. The production of similar floral organ defects in the severe AGL13 + SRDX and SEP2 + SRDX plants and the similar enhancement of AG nuclear localization efficiency by AGL13 and SEP3 proteins suggest a similar function for AGL13 and E functional SEP proteins. Additional fluorescence resonance energy transfer (FRET) analysis indicated that, similar to SEP proteins, AGL13 is able to interact with AG to form quartet‐like complexes (AGL13–AG)2 and interact with AG–AP3–PI to form a higher‐order heterotetrameric complex (AGL13–AG–AP3–PI). Through these complexes, AGL13 and AG could regulate the expression of similar downstream genes involved in pollen morphogenesis, anther cell layer formation and the ovule development. AGL13 also regulates AG/AP3/PI expression by positive regulatory feedback loops and suppresses its own expression through negative regulatory feedback loops by activating AGL6, which acts as a repressor of AGL13. Our data suggest that AGL13 is likely a putative ancestor for the E functional genes which specifies male and female gametophyte morphogenesis in plants during evolution. 相似文献
16.
Yi-Bo Zeng Dong-Mei Zhang Hongyan Li Hongzhe Sun 《Journal of biological inorganic chemistry》2008,13(7):1121-1131
Hpn-like (Hpnl) protein, encoded by the hpnl gene in Helicobacter pylori and featuring a histidine-rich and two glutamine-rich motifs, can render nickel tolerance to H. pylori when the external nickel level reaches toxic limits. We found that the recombinant Hpnl exists as an oligomer in the native
state and binds to two molar equivalents of nickel ions per monomer with a dissociation constant of 3.8 μM. Nickel could be
released from Hpnl either at acidic pH (pH1/2 4.6) or in the presence of chelate ligands, such as EDTA (t
1/2 = 220, 355, and 716 min at pH 6.0, 7.0, and 7.5, respectively). Our combined spectroscopic data show that nickel ion coordinates
to a nitrogen of a histidine residue possibly with a coordination number of four (square-planar geometry) or five. The growth
of Escherichia coli cells with or without the hpnl gene implied a protective role of Hpnl under higher concentrations of external nickel ions. Hpnl may serve a role in binding/storage
or detoxification of excess nickel ions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Competition for pollination is thought to be an important factor structuring flowering in many plant communities, particularly
among plant taxa with morphologically similar and easily accessible flowers. We examined the potential for heterospecific
pollen transfer (HPT) in a community of four Acacia species in a highly seasonal tropical habitat in Mexico. Partitioning of pollen flow among sympatric species appears to be
achieved, in part, through segregation of flowering in seasonal time, and interspecific differences in pollinator guilds.
However, two coflowering species (Acacia macracantha and Acacia angustissima) shared multiple flower visitors, raising the possibility of HPT. Each of these coflowering species showed high intraspecific
daily synchrony in pollen release, but dehisce at different times of day. Pollinators rapidly harvested available pollen from
one species before abandoning it to visit the flowers of the second later in the day. The activity of shared pollinators,
predominantly bees, is thus structured throughout the day, and potential for HPT reduced. Suggestive evidence in favour of
a resource partitioning explanation for this pattern is provided by the fact that A. macracantha showed significantly greater intraspecific synchrony when coflowering with a potential competitor (A. angustissima) than when flowering alone. We discuss our results in light of previous work on coflowering acacia assemblages in Tanzania
and Australia.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Nigel E. RaineEmail: |
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19.
Jorge Lora Pilar S Testillano Maria C Risueño Jose I Hormaza Maria Herrero 《BMC plant biology》2009,9(1):129-10
Background
In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. 相似文献20.
We report here the molecular and cytological characterization of two proteins, ScoHET1 and ScoHET2 (for Sciara coprophila heterochromatin), which associate to constitutive heterochromatin in the dipteran S. coprophila. Both proteins, ScoHET1 of 37 kDa and ScoHET2 of 44 kDa, display two chromodomain motifs that contain the conserved residues
essential for the recognition of methylated histone H3 at lysine 9. We raised antibodies to analyze the chromosomal location
of ScoHET1 and ScoHET2 in somatic and germline cells. In S. coprophila polytene chromosomes, both proteins associate to the pericentromeric regions and to the heterochromatic subterminal bands
of the chromosomes. In germinal nuclei, ScoHET1 and ScoHET2 proteins distribute to the heterochromatic regions of the regular
chromosome complement and are abundantly present along the heterochromatic germline-limited “L” chromosomes. We investigated
histone methylation modifications and found that all heterochromatic regions enriched in ScoHET1/ScoHET2 proteins exhibit
high levels of di- and tri-methylated histone H3 at lysine 9. Taken together, our results support that the association of
ScoHET1/ScoHET2 to heterochromatin is mediated by histone H3K9 methylation. Using 5-methylcytosine antibodies, we proved the
cytological detection of DNA methylation in S. coprophila. From our observations in L germline chromosomes, heterochromatin in S. coprophila is highly enriched in DNA 5-methylcytosine residues.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献