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1.
A cDNA coding for a putative auxin efflux carrier was amplified from Pisum sativum seedling shoot tips by RT-PCR and the corresponding full-length cDNA, PsPIN1, was subsequently obtained by RACE-PCR. The deduced amino acid sequence (599 residues) showed the three domain topology typical of the other PIN proteins. The PsPIN1 protein structure prediction possessed five transmembrane domains at both the N-(7-150) and C-(450-575) termini and a hydrophylic region in the middle. PsPIN1 showed highest similarity to Medicago, MtPIN4. Using the Genome Walking technique, a 1511 bp upstream region for PsPIN1 gene was sequenced. This PsPIN1 upstream region possessed multiple putative auxin, GA and light regulatory elements. The PsPIN1 mRNA was ubiquitously expressed throughout the pea plant, especially in growing tissues. Auxin induced PsPIN1 mRNA in dark grown pea seedling shoot tips. It was induced by 4-chloro-IAA, which is also an active auxin in pea, and by gibberellin (GA3). Interestingly, the PsPIN1 mRNA was down-regulated by light treatment, possibly because light negatively regulates auxin and, especially GA levels in pea. Thus PIN1-mediated auxin efflux is a highly regulated process, not only at the level of protein localization, but also at the level of mRNA accumulation. 相似文献
2.
Transient expression studies using blueberry leaf explants and monitored by -glucuronidase (GUS) assays indicated Agrobacterium tumefaciens strain EHA105 was more effective than LBA4404 or GV3101; and the use of acetosyringone (AS) at 100 M for inoculation and 6 days co-cultivation was optimum compared to 2, 4, 8, 10 or 12 days. Subsequently, explants of the cultivars Aurora, Bluecrop, Brigitta, and Legacy were inoculated with strain EHA105 containing the binary vector pBISN1 with the neomycin phosphotransferase gene (nptII) and an intron-interrupted GUS gene directed by the chimeric super promoter (Aocs)3AmasPmas. Co-cultivation was for 6 days on modified woody plant medium (WPM) plus 100 M AS. Explants were then placed on modified WPM supplemented with 1.0 mg l–1 thidiazuron, 0.5 mg l–1 -naphthaleneacetic, 10 mg l–1 kanamycin (Km), and 250 mg l–1 cefotaxime. Selection for Km-resistant shoots was carried out in the dark for 2 weeks followed by culture in the light at 30 E m–2 s–1 at 25°C. After 12 weeks, selected shoots that were both Km resistant and GUS positive were obtained from 15.3% of the inoculated leaf explants of cultivar Aurora. Sixty-eight independent clones derived from such shoots all tested positive by the polymerase chain reaction using a nptII primer. Eight of eight among these 68 clones tested positive by Southern hybridization using a gusA gene derived probe. The transformation protocol also yielded Km-resistant, GUS-positive shoots that were also PCR positive at frequencies of 5.0% for Bluecrop, 10.0% for Brigitta and 5.6% for Legacy. 相似文献
3.
Microarray Analysis of Gene Expression Involved in Anther Development in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) 总被引:6,自引:0,他引:6
Wang Z Liang Y Li C Xu Y Lan L Zhao D Chen C Xu Z Xue Y Chong K 《Plant molecular biology》2005,58(5):721-737
In flowering plants, anthers bear male gametophytes whose development is regulated by the elaborate coordination of many genes. In addition, both gibberellic acid (GA3) and jasmonic acid (JA) play important roles in anther development and pollen fertility. To facilitate the analysis of anther development genes and how GA3 and JA regulate anther development, we performed microarray experiments using a 10-K cDNA microarray with probes derived from seedlings, meiotic anthers, mature anthers and GA3- or JA-treated suspension cells of rice. The expression level change of 2155 genes was significantly (by 2-fold or greater) detected in anthers compared with seedlings. Forty-seven genes, representing genes with potential function in cell cycle and cell structure regulation, hormone response, photosynthesis, stress resistance and metabolism, were differentially expressed in meiotic and mature anthers. Moreover, 314 genes responded to either GA3 or JA treatment, and 24 GA3- and 82 JA-responsive genes showed significant changes in expression between meiosis and the mature anther stages. RT-PCR demonstrated that gene y656d05 was not only highly expressed in meiotic anthers but also induced by GA3. Strong RNA signals of y656d05 were detected in pollen mother cells and tapetum in in situ hybridization. Further characterization of these candidate genes can contribute to the understanding of the molecular mechanism of anther development and the involvement of JA and GA3 signals in the control of anther development in rice. 相似文献
4.
Investigations on seeds of Scrophularia marilandica L. were undertaken to determine their germination requirements. Seeds were collected from three naturally occurring sites
and one greenhouse-grown population in London, Ontario in September and October of 1997. Some were set to germinate immediately
after collection; others were stored in or on soil outside and/or under controlled laboratory conditions before testing. Germination
was assessed under two light/temperature regimes (35°C 14 h light, 20°C 10 h dark and 25°C 14 h light, 10°C 10 h dark), in
continuous darkness, and in the presence of two germination-promoting chemicals (GA3 and KNO3). Fresh seeds germinated best at 35/20°C, while stored seeds germinated best at 25/10°C. No differences in percent germination
were found among three seed-maturity stages. All chemical treatments, except 0.01 M KNO3, increased percent germination. Significant differences were found both among and within sites for most chemical treatments,
but exposure to 3 × 10−4 M GA3 caused almost every seed to germinate. When compared to the control, both the gibberellic acid and the soil-storage treatments
contributed to faster germination. Exposure of seeds to naturally prevailing conditions on the soil surface followed by testing
under the 25/10°C regime produced the highest percent germination. No seeds germinated in the dark. In summary, seeds of S. marilandica exhibit physiological dormancy, which can be alleviated by exposure to light, after-ripening and/or cold stratification.
It is probable that the differences in germination response among sites can be attributed to differences in environmental
conditions during seed production. These experiments indicate that the seeds of S. marilandica must be buried shortly after dispersal in order to form a persistent seed bank. 相似文献
5.
Summary Coconut (Cocos nucifera L.) plantlets grown in vitro often grow slowly when transferred to the field possibly, due to a limited photosynthetic capacity of in vitro-cultured plantlets, apparently caused by the sucrose added to growth medium causing negative feedback for photosynthesis.
In this paper, we tested the hypothesis that high exogenous sucrose will decrease ribulose 1,5-bisphosphate carboxylase (Rubisco)
activity and photosynthesis resulting in limited ex vitro growth. Plantlets grown with high exogenous sucrose (90 gl−1) had reduced photosynthetic activity that resulted in a poor photosynthetic response to high levels of light and CO2. These plantlets also had low amounts of Rubisco protein, low Rubisco activity, and reduced growth despite showing high survival
when transferred to the field. Decreasing the medium’s sucrose concentration from 90 to 22.5 gl−1 or 0 gl−1 resulted in increased photosynthetic response to light and CO2 along with increased Rubisco and phosphoenolpyruvate carboxylase (PEPC) activities and proteins. However, plantlets grown
in vitro without exogenous sucrose died when transferred ex vitro, whereas those grown with intermediate exogenous sucrose showed intermediate photosynthetic response, high survival, fast
growth, and ex vitro photosynthesis. Thus, exogenous sucrose at moderate concentration decreased photosynthesis but increased survival, suggesting
that both in vitro photosynthesis and exogenous sucrose reserves contribute to field establisment and growth of coconut plantlets cultured in vitro. 相似文献
6.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
7.
8.
9.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
10.
Hai Ping Hong Hongyi Zhang Paula Olhoft Steve Hill Hunt Wiley Effie Toren Helke Hillebrand Todd Jones Ming Cheng 《In vitro cellular & developmental biology. Plant》2007,43(6):558-568
A regeneration and transformation system has been developed using organogenic calluses derived from soybean axillary nodes
as the starting explants. Leaf-node or cotyledonary-node explants were prepared from 7 to 8-d-old seedlings. Callus was induced
on medium containing either Murashige and Skoog (MS) salts or modified Finer and Nagasawa (FNL) salts and B5 vitamins with
various concentrations of benzylamino purine (BA) and thidiazuron (TDZ). The combination of BA and TDZ had a synergistic effect
on callus induction. Shoot differentiation from the callus occurred once the callus was transferred to medium containing a
low concentration of BA. Subsequently, shoots were elongated on medium containing indole-3-acetic acid (IAA), zeatin riboside,
and gibberellic acid (GA). Plant regeneration from callus occurred 90 ∼ 120 d after the callus was cultured on shoot induction
medium. Both the primary callus and the proliferated callus were used as explants for Agrobacterium-mediated transformation. The calluses were inoculated with A. tumefaciens harboring a binary vector with the bar gene as the selectable marker gene and the gusINT gene for GUS expression. Usually 60–100% of the callus showed transient GUS expression 5 d after inoculation. Infected
calluses were then selected on media amended with various concentrations of glufosinate. Transgenic soybean plants have been
regenerated and established in the greenhouse. GUS expression was exhibited in various tissues and plant organs, including
leaf, stem, and roots. Southern and T1 plant segregation analysis of transgenic events showed that transgenes were integrated into the soybean genome with a copy
number ranging from 1–5 copies. 相似文献
11.
Many bacteria adapt to microoxic conditions by synthesizing a particular cytochrome c oxidase (cbb
3) complex with a high affinity for O2, encoded by the ccoNOQP operon. A survey of genome databases indicates that ccoNOQP sequences are widespread in all sub-branches of Proteobacteria but otherwise are found only in bacteria of the CFB group (Cytophaga, Flexibacter, Bacteroides). Our analysis of available genome sequences suggests four major strategies of regulating ccoNOQP expression in response to O2. The most widespread strategy involves direct regulation by the O2-responsive protein Fnr. The second strategy involves an O2-insensitive paralogue of Fnr, FixK, whose expression is regulated by the O2-responding FixLJ two-component system. A third strategy of mixed regulation operates in bacteria carrying both fnr and fixLJ-fixK genes. Another, not yet identified, strategy is likely to operate in the -Proteobacteria Helicobacter pylori and Campylobacter jejuni which lack fnr and fixLJ-fixK genes. The FixLJ strategy appears specific for the -subclass of Proteobacteria but is not restricted to rhizobia in which it was originally discovered. 相似文献
12.
A pure, active cytochrome b
6
f was isolated from the chloroplasts of the marine green alga, Bryopsis
corticulans. To investigate and characterize this cytochrome b
6
f complex, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), absorption spectra measurement and HPLC were employed. It was shown that this purified complex contained four large subunits with apparent molecular masses of 34.8, 24, 18.7 and 16.7 kD. The ratio of Cyt b
6 to Cytf was 2.01 : 1. The cytochromeb
6
f was shown to catalyze the transfer of 73 electrons from decylplastoquinol to plastocyanin–ferricyanide per Cyt f per second. α-Carotene, one kind of carotenoid that has not been found to present in cytochrome b
6
f complex, was discovered in this preparation by reversed phase HPLC. It was different from β-carotene usually found in cytochrome b
6
f complex. The configuration of the major α-carotene component was assigned to be 9-cis by resonance Raman spectroscopy. Different from the previous reports, the configuration of this α-carotene in dissociated state was determined to be all-trans. Besides this carotene, chlorophyll a was also found in this complex. It was shown that the molecular ratios of chlorophylla, cis and all-trans-α-carotene to Cyt f in this complex were 1.2, 0.7 and 0.2, respectively. 相似文献
13.
Summary A new species of Macroptilium sect. Microcochle (Benth.) J. A. Lackey is herein described from the states of Piauí and Bahia, Brazil. Macroptilium cochleatum is characterized by few-flowered inflorescences, calyx teeth longer than the tube, a tightly four-coiled keel, and linear,
patent fruits. The discovery of this unique Macroptilium species, with its distally coiled keel, expands the diagnostic features of the genus. A key to the Brazilian species of sect.
Microcochle is provided. 相似文献
14.
Michal Moyal Ben Zvi Amir Zuker Marianna Ovadis Elena Shklarman Hagit Ben-Meir Shamir Zenvirt Alexander Vainstein 《Molecular breeding : new strategies in plant improvement》2008,22(4):543-553
As a major contributor to the flower market, Gypsophila paniculata is an important target for the breeding of new varieties. However, gypsophila breeding is strongly hampered by the sterility
of this species’ genotypes and the lack of a genetic-transformation procedure for this genus. Here we describe the establishment
of a transformation procedure for gypsophila (Gypsophila paniculata L.) based on Agrobacterium inoculation of highly regenerative stem segments. The transformation procedure employs stem explants derived from GA3-pretreated mother plants and a two-step selection scheme. The GA3 treatment was crucial for obtaining high gene-transfer frequencies (75–90% GUS-expressing explants out of total inoculated
explants), as shown using three different gypsophila varieties. An overall transformation efficiency of five GUS-expressing
shoots per 100 stem explants was demonstrated for cv. Arbel. The applicability of the transformation system to gypsophila
was further reinforced by the generation of transgenic plants expressing Agrobacterium rhizogenes
rolC driven by a CaMV 35S promoter. Transgenic gypsophila plantlets exhibited extensive rooting and branching, traits that could
be beneficial to the ornamental industry. 相似文献
15.
The kinetics of the ubiquinol-cytochrome c reductase reaction was examined using membrane fragments and purified bc(1) complexes derived from a wild-type (WT) and a newly constructed mutant (MUT) strains of Paracoccus denitrificans. The cytochrome c(1) of the WT samples possessed an additional stretch of acidic amino acids, which was lacking in the mutant. The reaction was followed with positively charged mitochondrial and negatively charged bacterial cytochromes c, and specific activities, apparent k(cat) values, and first-order rate constant values were compared. These values were distinctly lower for the MUT fractions using mitochondrial cytochrome c but differed only slightly with the bacterial species. The MUT preparations were less sensitive to changes of ionic strength of the reaction media and showed pure first-order kinetics with both samples of cytochrome c. The reaction of the WT enzyme was first order only with bacterial cytochrome c but proceeded with a non-linear profile with mitochondrial cytochrome c. The analysis of the reaction pattern revealed a rapid onset of the reaction with a successively declining rate. Experiments performed in the absence of an electron donor indicated that electrostatic attraction could directly participate in cytochrome c reduction. 相似文献
16.
Smirnova IA Zaslavsky D Fee JA Gennis RB Brzezinski P 《Journal of bioenergetics and biomembranes》2008,40(4):281-287
The ba
3-type cytochrome c oxidase from Thermus thermophilus is phylogenetically very distant from the aa
3–type cytochrome c oxidases. Nevertheless, both types of oxidases have the same number of redox-active metal sites and the reduction of O2 to water is catalysed at a haem a
3-CuB catalytic site. The three-dimensional structure of the ba
3 oxidase reveals three possible proton-conducting pathways showing very low homology compared to those of the mitochondrial,
Rhodobacter sphaeroides and Paracoccus denitrificans aa
3 oxidases. In this study we investigated the oxidative part of the catalytic cycle of the ba
3
-cytochrome c oxidase using the flow-flash method. After flash-induced dissociation of CO from the fully reduced enzyme in the presence
of oxygen we observed rapid oxidation of cytochrome b (k ≅ 6.8 × 104 s−1) and formation of the peroxy (PR) intermediate. In the next step a proton was taken up from solution with a rate constant of ~1.7 × 104 s−1, associated with formation of the ferryl (F) intermediate, simultaneous with transient reduction of haem b. Finally, the enzyme was oxidized with a rate constant of ~1,100 s−1, accompanied by additional proton uptake. The total proton uptake stoichiometry in the oxidative part of the catalytic cycle
was ~1.5 protons per enzyme molecule. The results support the earlier proposal that the PR and F intermediate spectra are similar (Siletsky et al. Biochim Biophys Acta 1767:138, 2007) and show that even though the architecture of the proton-conducting pathways is different in the ba
3 oxidases, the proton-uptake reactions occur over the same time scales as in the aa
3-type oxidases.
Smirnova and Zaslavsky contributed equally to the work described in this paper. 相似文献
17.
Dong-Yuan Zhang Na Chen Yan-Zhuo Yang Qian Zhang Jian-Quan Liu 《Conservation Genetics》2008,9(2):475-477
Rhubarb is an important Traditional Chinese Medicine. However, the wild resource has been declining. In order to design appropriate
conservation methods for the official species across their natural distributions, it is important to characterize their genetic
diversity. Here, we describe the development of 10 new microsatellite loci for AC/TG/CCA in Rheum tanguticum. The microsatellites were enriched using the combined biotin capture method. The polymorphism of each locus was further assessed
in 12 individuals from four geographically distinct populations of this species. The number of alleles ranged from three to
seven and the expected heterozygosity ranged from 0.53 to 0.73. All markers have been checked in the other three species in
the genus and two of them together comprise the official medicinal rhubarb resource with R. tanguticum. These microsatellite markers could provide a useful tool for genetic and conservation studies of the rhubarb species. 相似文献
18.
A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
19.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献
20.
Aim of this study was to investigate the nature of dormancy in black henbane (Hyoscyamus niger) seeds which have low germination rate under normal laboratory conditions. To do this, before placing the seeds in Petri
dishes, they were soaked in 5,10 and 15 mg/L GA; 1,2 and 3% H2SO4, 15 mg/L GA + 1% H2SO4, 0.01 M KNO3 solutions, tap water, 40, 50 and 60°C hot water for 30 min. The study was performed under both continuous illumination and
darkness in growth chambers to evaluate the effect of light on germination rate. The results showed that H2SO4 and GA treatments were the most important factors affecting seed germination and their germination enhancing effects were
more evident in darkness. The results also suggested that black henbane seeds exhibit double dormancy involving a hard seed
coat and a partially dormant embryo and have a partial dark requirement to germinate. 相似文献