共查询到20条相似文献,搜索用时 31 毫秒
1.
A technique is described which permits the in vivo study of protein synthesis and phosphorylation in the pollen of Brassica spp. during the early stages of the pollen-stigma interaction. In Brassica napus and B. oleracea, compatible pollination is followed by a dramatic activation of protein synthesis in the pollen involving the synthesis of approximately 40 proteins. After incompatible pollinations in B. oleracea, virtually no newly synthesised polypeptides were detected in the pollen except for a small group of high molecular weight proteins which were not normally synthesised during compatible pollinations. Both compatible and incompatible pollinations were followed by the appearance of newly phosphorylated proteins in the pollen; these fell into four distinct groups. In B. oleracea, the number of phosphorylated proteins and the degree of phosphorylation of individual proteins within the four groups differed between compatible and incompatible pollinations. One group of phosphorylated proteins appeared to correspond with the small group of high molecular weight polypeptides which were synthesised in pollen after incompatible pollinations. These findings are discussed in the perspective of cell signalling during the pollen-stigma interaction in Brassica and also in terms of their possible implication in sporophytic self-incompatibility. 相似文献
2.
Pollen proteins of Lilium longiflorum were examined at different developmental stages (young, mature and cultured) using two-dimensional differential gel electrophoresis. Quantitative changes of six proteins (MP1–MP6) during pollen development were observed in the acidic and low molecular weight region. After water absorption on the culture medium, the quantities of all six proteins were drastically changed. Mass spectrometric analysis revealed that MP2, MP3, MP4 and MP6 are late embryogenesis abundant (LEA) (D-7) protein, profilin 3, profilin 1 and enolase, respectively. The remaining two proteins (MP1 and MP5) could not be identified by mass spectrometric analysis. Immunogold electron microscopic examination showed the presence of these proteins in different regions: MP1 around lipid bodies, suggesting possible involvement in lipid metabolism, MP4 near actin in the cytoplasm, indicating the possibility of its interaction with actin in the regulatory pathways of pollen, and MP2 and MP6 in the cytoplasm. 相似文献
3.
4.
Sviridov AV Shushkova TV Zelenkova NF Vinokurova NG Morgunov IG Ermakova IT Leontievsky AA 《Applied microbiology and biotechnology》2012,93(2):787-796
Bacterial strains capable of utilizing methylphosphonic acid (MP) or glyphosate (GP) as the sole sources of phosphorus were
isolated from soils contaminated with these organophosphonates. The strains isolated from MP-contaminated soils grew on MP
and failed to grow on GP. One group of the isolates from GP-contaminated soils grew only on MP, while the other one grew on
MP and GP. Strains Achromobacter sp. MPS 12 (VKM B-2694), MP degraders group, and Ochrobactrum anthropi GPK 3 (VKM B-2554D), GP degraders group, demonstrated the best degradative capabilities towards MP and GP, respectively,
and were studied for the distribution of their organophosphonate catabolism systems. In Achromobacter sp. MPS 12, degradation of MP was catalyzed by C–P lyase incapable of degrading GP (C–P lyase I). Adaptation to growth on
GP yielded the strain Achromobacter sp. MPS 12A, which retained its ability to degrade MP via C–P lyase I and was capable of degrading GP with formation of sarcosine,
thus suggesting the involvement of a GP-specific C–P lyase II. O. anthropi GPK 3 also degraded MP via C–P lyase I, but degradation of GP in it was initiated by glyphosate oxidoreductase, which was
followed by product transformation via the phosphonatase pathway. 相似文献
5.
María Suárez-Cervera Juan A. Asturias Ana Vega-Maray Teresa Castells Carmen López-Iglesias Ignacio Ibarrola M. Carmen. Arilla Nina Gabarayeva Juan A. Seoane-Camba 《Sexual plant reproduction》2005,18(3):101-112
Platanus acerifolia (Aiton) Willdenow is a plane tree, widely grown as an ornamental tree in many cities of the United States and Western Europe,
which has become an important source of airborne allergens in our cities. The aim of the present study is to immunolocalize
the major allergens in the pollen grain and to examine their potential function in the fertilization process. Observations
were made in mature and hydrated, activated pollen of P. acerifolia for 5, 15, 30 min and 2 h in the germination medium. Specimens were fixed using freezing protocols for transmission electron
microscopy (TEM). For immunogold labelling, cryosections and resin-embedded ultrathin sections were incubated using rabbit
antisera against the purified pollen allergens Pla a 1 and Pla a 2. Elution of P. acerifolia allergens took place after 5 min of pollen incubation in buffered medium. Intense labelling of Pla a 1 and Pla a 2 was detected
after pollen exudates were released. In pollen grains, Pla a 1 was predominantly localized in concentric cisternae of the
endoplasmic reticulum (ER), situated between the vegetative nucleus and the generative cell, and was released from pollen
grains 5 min after hydration; cytoplasmic localization decreased 15 min after hydration. In pollen grains, glycoprotein Pla
a 2 was abundant in association with Golgi cisternae and vesicles situated in the apertural periphery of the mature pollen
grains. Pla a 2 proteins were also detected in ER and in the generative cell wall. Immunolabelling of Pla a 2 decreased 5 min
after pollen hydration but was again intense after 15–30 min in germination medium, presumably as a consequence of renewed
expression and glycosylation of this protein. Pla a 1 belongs to a new class of allergens related to proteinaceous invertase
and pectin methyl esterase inhibitors (PII, PMEI) which could be involved in membrane protection and pectin de-esterification
control during pollen hydration. Pla a 2 has an exopolygalacturonase (PG) enzymatic activity consistent with pollen-stigma
adhesion mechanisms or compatibility systems. Moreover, the expression of Pla a 2 found 15–30 min after hydration might contribute
to pollen-tube growth and the modification of transmitting tissue cell walls. The abundant production and elution of Pla a
1 and Pla a 2 proteins may alter the environment in which pollen tube elongation occurs, thus promoting a potential crosstalk
between the pollen and the gynoecium. 相似文献
6.
Pyrus pyrifolia stylar S-RNase induces alterations in the actin cytoskeleton in self-pollen and tubes in vitro 总被引:1,自引:0,他引:1
Summary. Pears (Pyrus pyrifolia L.) have an S-RNase-based gametophytic self-incompatibility system, and S-RNases have also been implicated in self-pollen
or genetically identical pollen rejection. Tip growth of the pollen tube is dependent on a functioning actin cytoskeleton.
In this study, configurations of the actin cytoskeleton in P. pyrifolia pollen and effects of stylar S-RNases on its dynamics were investigated by fluorescence and confocal microscopy. Results
show that actin filaments in normal pollen grains exist in fusiform or circular structures. When the pollen germinates, actin
filaments assembled around one of the germination pores, and then actin bundles oriented axially throughout the shank of the
growing tube. There was a lack of actin filaments 5–15 μm from the tube tip. When self-stylar S-RNase was added to the basal
medium, pollen germination and tube growth were inhibited. The configuration of the actin cytoskeleton changed throughout
the culturing time: during the first 20 min, the actin configurations in the self-pollen and tube were similar to the control;
after 20 min of treatment, the actin filaments in the pollen tube gradually moved into a network running from the shank to
the tip; finally, there was punctate actin present throughout the whole tube. Although the actin filaments of the self-pollen
grain also disintegrated into punctate foci, the change was slower than in the tube. Furthermore, the alterations to the actin
cytoskeleton occurred prior to the arrest of pollen tube growth. These results suggest that P. pyrifolia stylar S-RNase induces alterations in the actin cytoskeleton in self-pollen grains and tubes.
Correspondence: Shao-ling Zhang, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People’s
Republic of China. 相似文献
7.
In Brassica, the thioredoxinhproteins, THL1 and THL2, were previously found to be potential inhibitors of the S receptor kinase (SRK) in the Brassica self-incompatibilty response. To investigate the biological roles of THL1 and THL2 in pollen–pistil interactions, the stigma-specific SLR1 promoter was used to drive antisense THL1/2 expression in Brassica napus cv. Westar. This cultivar is normally compatible, but antisense suppression of THL1/2 led to a low level constitutive rejection of all Brassica napus pollen tested. Fluorescence microscopy revealed that the pollen rejection was a typical Brassica self-incompatibility rejection response with reduced pollen adhesion, germination and pollen tube growth. In addition, Westar was found to express the SLG15 and SRK15 proteins which may be the target of regulation by THL1 and THL2. Thus, these results indicate that the THL1 and THL2 are required for full pollen acceptance in B. napus cv. Westar. 相似文献
8.
One of the rare weak points of the model plant Arabidopsis is the technical problem associated with the germination of its male gametophyte and the generation of the pollen tube in
vitro. Arabidopsis pollen being tricellular has a notoriously low in vitro germination compared to species with bicellular pollen. This drawback
strongly affects the reproducibility of experiments based on this cellular system. Together with the fact that pollen collection
from this species is tedious, these are obstacles for the standard use of Arabidopsis pollen for experiments that require high numbers of pollen tubes and for which the percentage of germination needs to be
highly reproducible. The possibility of freeze-storing pollen after bulk collection is a potential way to solve these problems,
but necessitates methods that ensure continued viability and reproducible capacity to germinate. Our objective was the optimization
of germination conditions for Arabidopsis pollen that had been freeze-stored. We optimized the concentrations of various media components conventionally used for in
vitro pollen germination. We found that in general 4 mM calcium, 1.62 mM boric acid, 1 mM potassium, 1 mM magnesium, 18% sucrose
at pH 7 and a temperature of 22.5°C are required for optimal pollen germination. However, different experimental setups may
deviate in their requirements from this general protocol. We suggest how to optimally use these optimized methods for different
practical experiments ranging from morphological observations of pollen tubes in optical and electron microscopy to their
bulk use for molecular and biochemical analyses or for experimental setups for which a specific medium stiffness is critical.
F. Bou Daher and Y. Chebli contributed equally to this study. 相似文献
9.
Murphy DJ 《Protoplasma》2006,228(1-3):31-39
Summary. I have used cellular and molecular genetic and bioinformatic approaches to characterise the components of the pollen coat
in plants of the family Brassicaceae, including Arabidopsis thaliana and several brassicas including Brassica napus, B. oleracea, and B. rapa. The pollen coat in these species is mostly made up of a unique mixture of lipids that is highly enriched in acylated compounds,
such as sterol esters and phospholipids. These acyl lipids are characterised by an unusually high degree of saturation. The
fatty acids typically contain 70–90% saturated acyl residues such as myristate, palmitate, and stearate. The major sterol
components of the pollen coat are saturated fatty acyl esters of stigmasterol, campesterol, and campestdienol. In addition
to lipids, the second major component of the pollen coat is a specific group of proteins that is dominated by a family of
proteins that we term pollenins. Although pollenins are by far the major protein components of the pollen coat of members
of the Brassicaceae, proteomic analysis reveals that there are several additional protein components, including lipases, protein
kinases, a pectin esterase, and a caleosin. The biosynthesis of these lipids and proteins and their significance for overall
pollen function are reviewed and discussed.
Correspondence and reprints: Biotechnology Unit, School of Applied Sciences, University of Glamorgan, Pontypridd CF37 1DL,
Wales, United Kingdom. 相似文献
10.
Adachi T Ito J Kawata K Kaya M Ishida H Sahara H Hata Y Ogino C Fukuda H Kondo A 《Applied microbiology and biotechnology》2008,81(4):711-719
A novel cell-surface display system was constructed in Aspergillus oryzae. Each of the five genes encoding the putative cell-wall-localized protein from the A. oryzae genome was cloned and these cell-surface anchor functions were examined by fusion to the C-terminal of the green fluorescent
protein (GFP). Using the MP1 and CWP proteins as anchor proteins, GFP signals were strongly observed on the cell surface of
recombinant A. oryzae. When these proteins were used as anchor proteins for cell-surface display of β-glucosidase from A. oryzae, enzyme activity was detected on the cell surface. In particular, β-glucosidase activity of recombinant A. oryzae using MP1, a putative glycosylphosphatidylinositol (GPI) anchor protein was higher than CWP. Based on these results, it was
concluded that the MP1 protein can act as a GPI-anchor protein in A. oryzae, and the proposed cell-surface display system using MP1 allows for the display of heterogeneous and endogenous proteins. 相似文献
11.
Scanning electron microscopy was employed to study and compare microspore embryogenesis in vitro with pollen development in planta inBrassica napus andB. oleracea. An exine with its specific pattern had already been formed, when microspores were released from tetrads. During subsequent pollen development, microspores increased in size and continued to strengthen the exine. Upon in vitro culture, all microspores, i.e., embryogenic and nonembryogenic, initially showed the same morphological features. After 24 h in culture, the microspores had increased in size. Thereafter, embryogenesis was indicated in some microspores by two different morphological changes. One featured an expansion in volume of the cell cluster around the germination aperture (type I), the other showed cell cluster volume expansion over the entire microspore surface (type II). Two-thirds of embryogenic microspores in bothB. napus andB. oleracea demonstrated type I development. When followed by fluorescence microscopy, in vitro culture of microspores revealed cultures with a high embryo frequency were those with a high frequency of symmetrical division.Abbreviations
SEM
Scanning electron microscopy
-
TEM
Transmission electron microscopy 相似文献
12.
13.
Pertl H Himly M Gehwolf R Kriechbaumer R Strasser D Michalke W Richter K Ferreira F Obermeyer G 《Planta》2001,213(1):132-141
A 14-3-3 protein has been cloned and sequenced from a cDNA library constructed from mRNAs of mature pollen grains of Lilium longiflorum Thunb. Monoclonal antibodies (MUP 5 or MUP 15) highly specific against 14-3-3 proteins recognised a 30-kDa protein in the
cytoplasmic fraction of many various lily tissues (leaves, bulbs, stems, anther filaments, pollen grains, stigmas) and in
other plants (Arabidopsis seedlings, barley recombinant 14-3-3). In addition, 14-3-3 proteins were detected in a microsomal fraction isolated from
pollen grains and tubes, and the amount of membrane-bound 14-3-3 proteins as well as the amount of the plasma membrane (PM)
H+ ATPase increased during germination of pollen grains and tube growth. No change was observed in the cytoplasmic fraction.
A further increase in the amount of 14-3-3 proteins in the microsomal fraction was observed when pollen grains were incubated
in germination medium containing 1 μM fusicoccin (FC) whereas the number of 14-3-3s in the cytoplasmic fraction decreased.
Fusicoccin also protected membrane-bound 14-3-3 proteins from dissociation after washing with the chaotropic salt KI. Furthermore,
FC stimulated the PM H+ ATPase activity, the germination frequency and the growth rate of pollen tubes, thus indicating that a modulation of the
PM H+ ATPase activity by interaction with 14-3-3 proteins may regulate germination and tube growth of lily pollen.
Received: 20 June 2000 / Accepted: 2 October 2000 相似文献
14.
15.
Xue-zhu Du Xian-hong Ge Xing-cheng Yao Zhi-gang Zhao Zai-yun Li 《Plant cell reports》2009,28(7):1105-1113
Intertribal somatic hybrids between Brassica napus (2n = 38, AACC) and a dye and medicinal plant Isatis indigotica (2n = 14, II) were obtained by fusions of mesophyll protoplasts. From a total of 237 calli, only one symmetric hybrid (S2) and
five asymmetric hybrids (As1, As4, As6, As7 and As12) were established in the field. These hybrids showed some morphological
variations and had very low pollen fertility. Hybrids S2 and As1 possessed 2n = 52 (AACCII), the sum of the parental chromosomes, and As12 had 2n = 66 (possibly AACCIIII). Hybrids As4, As6 and As7 were mixoploids (2n = 48–62). Genomic in situ hybridization analysis revealed that pollen mother cells at diakinesis of As1 contained 26 bivalents
comprising 19 from B. napus and 7 from I. indigotica and mainly showed the segregation 26:26 at anaphase I (AI) with 7 I. indigotica chromosomes in each polar group. Four BC1 plants from As1 after pollinated by B. napus resembled mainly B. napus in morphology but also exhibited some characteristics from I. indigotica. These plants produced some seeds on selfing or pollination by B. napus. They had 2n = 45 (AACCI) and underwent pairing among the I. indigotica chromosomes and/or between the chromosomes of two parents at diakinesis. All hybrids mainly had the AFLP banding patterns
from the addition of two parents plus some alterations. B. napus contributed chloroplast genomes in majority of the hybrids but some also had from I. indigotica. Production of B. napus–I. indigotica additions would be of considerable importance for genome analysis and breeding. 相似文献
16.
The existence of different kinds of kinases in pollen and pollen tubes suggests that kinase-mediated signaling pathways are likely involved in regulating pollen germination and pollen tube growth during the life cycle of higher plants. We have used RT-PCR and RACE to isolate full-length cDNAs for two pollen-expressed kinases, named NtPK1 and NtPK2, of Nicotiana tabacum. NtPK1 and NtPK2 encode proteins of 365 and 369 amino acids with calculated molecular masses of 39.2 kDa and 39.5 kDa, respectively, and both proteins possess the 12 sub-domains that are conserved among protein kinases. The nucleotide and deduced amino acid sequences of NtPK1 and NtPK2 share 88% and 91% identity, respectively, with the C-terminal region being the most conserved. RT-PCR analysis revealed that NtPK1 was specifically expressed in pollen and pollen tubes, and that NtPK2 was also expressed in pistil and petal. Immunoblot analysis using anti-NtPK1 and anti-NtPK2 antibodies confirmed that both NtPK1 and NtPK2 were produced in pollen and pollen tubes, and that NtPK2 was also produced in developing male gametophytes and other floral tissues. Biochemical fractionation experiments showed that, in all the tissues examined, NtPK1 and NtPK2 were present in the cytosolic fraction and not in the microsomal fraction. NtPK1 and NtPK2 were found to autophosphorylate on threonine and, for NtPK2, on serine as well. All the results taken together suggest that NtPK1 and NtPK2 are novel receptor-like cytosolic serine/threonine kinases, and could mediate signaling pathways required for pollen germination and/or pollen tube growth.The nucleotide sequence data of NtPK1 and NtPK2 reported in this paper will appear in the EMBL/GenBank/DDBJ nucleotide sequence databases under the accession numbers AJ608156 and AJ608157, respectively 相似文献
17.
Flavonol-deficient petunia pollen [conditionally male fertile (CMF) pollen] is unable to germinate but application of nanomolar
concentrations of flavonol aglycones completely restores function (Mo et al. 1992). In this study a chemically synthesized
radioactive flavonol, [4′-O-14C]kaempferide, was used as a model compound to study the metabolism of flavonols during the first few hours of pollen germination.
[4′-O-14C] Kaempferide was as efficient at inducing CMF pollen germination as kaempferol and quercetin, the aglycone form of the endogenous
flavonols in petunia pollen. Analysis by high-performance liquid chromatography (HPLC) of extracts from both in-vitro-germinated
pollen and the germination medium showed that more than 95% of the applied radioactivity was recovered as three kaempferide
3-O-glycosides and unmetabolized kaempferide; no flavonol catabolites were detected. Only HPLC fractions that contained the aglycone, or produced
it upon acid hydrolysis, could induce CMF pollen germination in vitro. Structurally diverse flavonols could be classified
according to how efficiently the aglycone was internalized and glycosylated during pollen germination. The ability of an individual
flavonol to restore germination correlated with the total uptake of flavonols but not with the amount of glycoside formed
in the pollen. Thus this study reinforces the conclusion that flavonol aglycones are the active compound for inducing pollen
germination.
Received: 4 November 1996/Accepted: 4 December 1996 相似文献
18.
Pollination in species with dry stigmas begins with the hydration of desiccated pollen grains on the stigma, a highly regulated
process involving the proteins and lipids of the pollen coat and stigma cuticle. Self-incompatible species of the Brassicaceae
block pollen hydration, and while the early signaling steps of the self-incompatibility response are well studied, the precise
mechanisms controlling pollen hydration are poorly understood. Both lipids and proteins are important for hydration; loss
of pollen coat lipids and proteins results in defective or delayed hydration on the stigma surface. Here, we examine the role
of the pollen coat protein extracellular lipase 4 (EXL4), in the initial steps of pollination, namely hydration on the stigma.
We identify a mutant allele, exl4-1, that shows a reduced rate of pollen hydration. exl4-1 pollen is normal with respect to pollen morphology and the downstream steps in pollination, including pollen tube germination,
growth, and fertilization of ovules. However, owing to the delay in hydration, exl4-1 pollen is at a disadvantage when competed with wild-type pollen. EXL4 also functions in combination with GRP17 to promote the initiation of hydration. EXL4 is similar to GDSL lipases, and we show that it functions in hydrolyzing ester bonds. We report a previously unknown function
for EXL4, an abundant pollen coat protein, in promoting pollen hydration on the stigma. Our results indicate that changes in lipid
composition at the pollen–stigma interface, possibly mediated by EXLs, are required for efficient pollination in species with
dry stigmas. 相似文献
19.
The intertribal sexual hybrids between three Brassica napus (2n = 38) cultivars and Lesquerella fendleri (2n = 12) with the latter as pollen parent were obtained and characterized for their phenotypes and chromosomal and genomic constitutions.
F1 plants and their progenies mainly resembled female B. napus parents, while certain characters of L. fendleri were expressed in some plants, such as longer flowering period, basal clustering stems and particularly the glutinous layer
on seed coats related to drought tolerance. Twenty-seven F1 plants were cytologically classified into five types: type I (16 plants) had 2n = 38, type II (2) had 2n = 38–42, type III (3) had 2n = 31–38, type IV (5) had 2n = 25–31, and type V (1) had 2n = 19–22. Some hybrids and their progenies were mixoploids in nature with only 1–2 chromosomes or some chromosomal fragments
of L. fendleri included in their cells. AFLP (Amplified fragments length polymorphism) analysis revealed that bands absent in B. napus, novel for two parents and specific for L. fendleri appeared in all F1 plants and their progenies. Some progenies had the modified fatty acid profiles with higher levels of linoleic, linolenic,
eicosanoic and erucic acids than those of B. napus parents. The occurrence of these partial hybrids with phenotypes, genomic and fatty acid alterations resulted possibly from
the chromosome elimination and doubling accompanied by the introgression of alien DNA segments and genomic reorganization.
The progenies with some useful traits from L. fendleri should be new and valuable resource for rapeseed breeding. 相似文献
20.
Xiaoguang Zhao Wenguo Wang Yaodong Li Jie Xing Fang Chen Shenghua Wang 《Plant Cell, Tissue and Organ Culture》2007,91(1):53-60
Microspores cultured in vitro can be regarded as a system to study gene regulation, cell fate determination and cell differentiation
during pollen development as well as an alternative method of genetic transformation in plants. In our study, pollen development
and viability in Orychophragmus violaceus in vivo were determined and then pollen from the late unicellular stage was cultured in vitro. MS liquid medium + White vitamins + 2%
(V/V) coconut milk + 0.5 M maltose, pH = 7.0 was the most appropriate for in vitro culture of Orychophragmus violaceus microspores. With this medium, the rates of in maturation and germination were 19.3% and 4.7%, respectively. Liquid medium
with 0.6 M maltose + 1.6 mM boric acid + 2.9 mM Ca(NO3)2 + 29.6 μM vitamin B1, pH = 7.0 was optimal for germination of pollen matured in vivo. The rate of germination was 70.7%.
Pollen matured in vitro cultured in similar medium exhibited a rate of germination of 62.7%. Hence, the experimental study
showed that in vitro maturation of microspores is feasible and this experimental system can be applied to further theoretical
and practical research. 相似文献