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Citrus FT (CiFT) cDNA, which promoted the transition from the vegetative to the reproductive phase in Arabidopsis thaliana, when constitutively expressed was introduced into trifoliate orange (Poncirus trifoliata L. Raf.). The transgenic plants in which CiFT was expressed constitutively showed early flowering, fruiting, and characteristic morphological changes. They started to
flower as early as 12 weeks after transfer to a greenhouse, whereas wild-type plants usually have a long juvenile period of
several years. Most of the transgenic flowers developed on leafy inflorescences, apparently in place of thorns; however, wild-type
adult trifoliate orange usually develops solitary flowers in the axils of leaves. All of the transgenic lines accumulated
CiFT mRNA in their shoots, but there were variations in the accumulation level. The transgenic lines showed variation in phenotypes,
such as time to first flowering and tree shape. In F1 progeny obtained by crossing ‘Kiyomi’ tangor (C. unshiu × sinensis) with the pollen of one transgenic line, extremely early flowering immediately after germination was observed. The transgene
segregated in F1 progeny in a Mendelian fashion, with complete co-segregation of the transgene and the early flowering phenotype. These results
showed that constitutive expression of CiFT can reduce the generation time in trifoliate orange. 相似文献
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Kexue Li Youning Wang Chunyu Han Wensheng Zhang Huizhen Jia Xia Li 《Plant Growth Regulation》2007,53(3):195-206
Flowering timing is very important for the reproductive success of higher plants. However, effects of salt on plant flowering
and the underlying molecular mechanisms are largely unknown. Here, we show that salt stress delays flowering in Arabidopsis in a dose-dependent manner. Mild salt stress (≤50 mM NaCl) promoted and prolonged the vegetative growth, whereas high salinity
(≥100 mM NaCl) largely delayed or inhibited the transition from vegetative growth to reproductive development. The gibberellin
(GA)-pathway plays an important role in this phenotype, and application of exogenous GA could restore late flowering induced
by salt. In addition, the CONSTANS (CO)/FLOWERING LOCUS T (FT) module may also play a critical role in mediating the effects of salt on flowering. The mRNA abundance of CO was significantly reduced by salt stress in a dose-dependent manner. The constans (co-2) mutants did not respond to moderate salt stress, whereas over-expressing CO manifested no delay in flowering time in response to salinity. Expression of FT, SOC1 and LFY in the downstream of the pathways was also reduced by salt according to dose. Moreover, salt-sensitive mutant salt overly sensitive3 (sos3) exhibited greater sensitivity in flowering, further suggesting that ion disequilibrium mediates salt-induced late flowering.
Kexue Li and Youning Wang contributed equally to this report. 相似文献
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Masaru Nakano Hiroto Umehara Yoshihiro Hara Motohide Makino Mika Igarashi Mutsumi Nakada Toru Nakamura Yoichiro Hoshino Akira Kanno 《Molecular breeding : new strategies in plant improvement》2007,20(4):425-429
The class B genes, which belong to the MADS-box gene family, play important roles in regulating petal and stamen development
in flowering plants. These genes exist in two different types termed DEF- and GLO-like genes, and the B-function is provided by heterodimers of a DEF- and a GLO-like gene product. In the present study, dicot (tobacco and lettuce) and monocot (Tricyrtis hirta) plants were transformed with the GLO-like gene of Agapanthus praecox ssp. orientalis
ApGLO alone or in combination with the DEF-like gene of the same plant ApDEF. In two out of 10 transgenic tobacco plants containing ApGLO, sepals partially converted into petaloid organs. For lettuce, ray florets of four out of nine transgenic plants containing
ApGLO also developed additional petaloid organs. In two out of five transgenic T. hirta plants containing both ApGLO and ApDEF, organs developed in whorl 4 showed noticeable morphological alteration: they were much longer compared with carpels of non-transgenic
plants, and had purple spots overall on the surface as filaments of non-transgenic plants. No morphological alterations were
observed in vegetative organs between transgenic and non-transgenic plants for all the three species. The results obtained
in the present study indicate a possibility of molecular breeding for flower form alteration by genetic transformation with
the class B MADS-box gene(s) of heterologous plant species. 相似文献
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The FT/TFL1 gene family encodes proteins with similarity to phosphatidylethanolamine binding proteins which function as flowering promoters
and repressors. We show here that the FT/TFL1 gene family in Vitis vinifera is composed of at least five genes. Sequence comparisons with homologous genes identified in other dicot species group them
in three major clades, the FT, MFT and TFL1 subfamilies, the latter including three of the Vitis sequences. Gene expression patterns are in agreement with a role of VvFT and VvMFT as flowering promoters; while VvTFL1A, VvTFL1B and VvTFL1C could be associated with vegetative development and maintenance of meristem indetermination. Overexpression of VvFT in transgenic Arabidopsis plants generates early flowering phenotypes similar to those produced by FT supporting a role for this gene in flowering promotion. Overexpression of VvTFL1A does not affect flowering time but the determination of flower meristems, strongly altering inflorescence structure, which
is consistent with the biological roles assigned to similar genes in other species. 相似文献
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To establish a procedure for Agrobacterium tumefaciens-mediated transformation of golden pothos (Epipremnum aureum) plants, the effects of selection antibiotics and the preculture period of stem explants before A. tumefaciens infection were examined. Explants were co-cultivated with A. tumefaciens EHA105, harboring the plasmid pGWB2/cGUS, on a somatic embryo-inducing medium supplemented with acetosyringone. Resulting
transgenic somatic embryos were screened on an antibiotic selection medium, and the transgenic pothos plants were regenerated
on a germination medium. Hygromycin was the optimum selection antibiotic tested. The preculture period significantly affected
the transformation efficiency, with explants precultured for one-day showing the best efficiency (5–30%). Both transformed
hygromycin-resistant embryos and regenerated plants showed β-glucuronidase activity. Southern blot analysis confirmed transgene
integration into the pothos genome. This reproducible transformation system for golden pothos may enable the molecular breeding
of this very common indoor plant. 相似文献
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We report here an in planta method to produce transgenic Brassica napus plants. The procedure included Agrobacterium-mediated inoculation of plants at various development stages along with a vacuum infiltration step. The flowering stage appeared to be the most receptive stage for transformation and production of transgenic plants. In some cases, the flowering stage was induced either by cold treatment or by high density planting. Molecular and genetic analysis revealed that single and multiple copy events were generated and that the transgenes were transmitted to the T1 and T2 progeny in a Mendelian fashion.Abbreviations AFP Adult flowering plants - ELISA Enzyme linked immunosorbent assay - GS Germinating seedlings - GUS -Glucuronidase - ISFP Induced small flowering plants - MS Murashige and Skoog - PPO Protoporphyrinogen oxidase - TE Tris-EDTA buffer - YEP Yeast extract-peptone mediumCommunicated by W.A. Parrott 相似文献
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Andrey Anisimov Kimmo Koivu Anne Kanerva Seppo Kaijalainen Kari Juntunen Viktor Kuvshinov 《Molecular breeding : new strategies in plant improvement》2007,19(3):241-253
The aim of our study was to identify the highest expressing rubisco small subunit (RbcS) promoters (pRbcS) from the cotyledons of germinating seedlings of Brassica rapa var. oleifera to drive high-level and preferably stage-specific transgenic protein expression in Brassicaceae plants. We cloned four new
pRbcS promoters using several approaches, including the construction of a cDNA library and use of genome walking technique. Real-time
PCR analysis of RbcS mRNA expression clearly showed that two of these promoters exhibited the highest activity on the germination stage of plant
development. We used gusA expression as a reporter of promoter activity in Brassica napus and Nicotiana tabacum plants that were transformed with the constructs using an Agrobacterium-mediated transformation strategy. The mRNA level
of RbcS and of gusA was quantified in transformed plants. The data obtained demonstrate that the promoter most active in seedlings under native
conditions was also most active in transgenic constructs at the same stage of plant development. The fine structure of the
promoters is discussed herein. 相似文献
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T. Zhang 《In vitro cellular & developmental biology. Plant》2007,43(2):91-94
This study investigated the factors affecting in vitro flowering of Perilla frutescens. The shoots regenerated from cotyledonary and hypocotyl explants cultured on Murashige and Skoog (MS) medium supplemented
with benzyladenine (BA) and indole-3-acetic acid, each at 0.5 mg l−1, were excised and transferred to MS medium containing 30 g l−1 of sucrose, 8.25 g l−1 of ammonium nitrate, and 1.0 mg l−1 of BA. After 40 d of culture, 86.2% of shoots flowered and most of which self-fertilized in vitro and produced mature fruits with viable seeds. These seeds were germinated and plants were grown to maturity and flowered
in soil under greenhouse conditions. The in vitro flowering system reported in this study may facilitate rapid breeding of P. frutescens and offers a model system for studying the physiological mechanism of flowering. 相似文献
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Plant aquaporins are believed to facilitate water transport across cell membranes. However, the relationship between aquaporins
and drought resistance in plants remains unclear. VfPIP1, a putative aquaporin gene, was isolated from Vicia faba leaf epidermis, and its expression was induced by abscisic acid (ABA). Our results indicated that the VfPIP1 protein was
localized in the plasma membrane, and its expression in V. faba was induced by 20% polyethylene glycol 6000. To further understand the function of VfPIP1, we obtained VfPIP1-expressing transgenic Arabidopsis thaliana plants under the control of the CaMV35S promoter. As compared to the wild-type control plants, the transgenic plants exhibited
a faster growth rate, a lower transpiration rate, and greater drought tolerance. In addition, the stomata of the transgenic
plants closed significantly faster than those of the control plants under ABA or dark treatment. These results suggest that
VfPIP1 expression may improve drought resistance of the transgenic plants by promoting stomatal closure under drought stress. 相似文献
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Phytochelatins (PCs) are post-translationally synthesized thiol reactive peptides that play important roles in detoxification
of heavy metal and metalloids in plants and other living organisms. The overall goal of this study is to develop transgenic
plants with increased tolerance for and accumulation of heavy metals and metalloids from soil by expressing an Arabidopsis
thaliana
AtPCS1 gene, encoding phytochelatin synthase (PCS), in Indian mustard (Brassica juncea L.). A FLAG-tagged AtPCS1 gDNA, under its native promoter, is expressed in Indian mustard, and transgenic pcs lines have been compared with wild-type
plants for tolerance to and accumulation of cadmium (Cd) and arsenic (As). Compared to wild type plants, transgenic plants
exhibit significantly higher tolerance to Cd and As. Shoots of Cd-treated pcs plants have significantly higher concentrations
of PCs and thiols than those of wild-type plants. Shoots of wild-type plants accumulated significantly more Cd than those
of transgenic plants, while accumulation of As in transgenic plants was similar to that in wild type plants. Although phytochelatin
synthase improves the ability of Indian mustard to tolerate higher levels of the heavy metal Cd and the metalloid As, it does
not increase the accumulation potential of these metals in the above ground tissues of Indian mustard plants. 相似文献
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Meadow fescue (Festuca pratensis Huds.) is an important cool-season forage grass in Europe and Asia. We developed a protocol for producing meadow fescue transgenic
plants mediated by Agrobacterium tumefaciens transformation. Embryogenic calli derived from mature embryos were transformed with A. tumefaciens strain AGL1 carrying the binary vector pDM805, coding for the phosphinothricin acetyltransferase (bar) and β-glucuronidase (uidA) genes. Bialaphos was used as the selective agent throughout all phases of tissue culture. In total, 40 independent transgenic
plants were recovered from 45 bialaphos-resistant callus lines and an average transformation efficiency of 2% was achieved.
The time frame from infection of embryogenic calli with Agrobacterium to transferring the transgenic plants to the greenhouse was 18 weeks. In a study of 11 BASTA-resistant transgenic lines,
the uidA gene was expressed in 82% of the transgenic lines. Southern blot analysis revealed that 82% of the tested lines integrated
one or two copies of the uidA gene.
C. Gao and J. Liu contributed equally to the work. 相似文献
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Recent studies of glucose (Glc) sensing and signaling have revealed that Glc acts as a critical signaling molecule in higher plants. Several Glc sensing-defective Arabidopsis mutants have been characterized in detail, and the corresponding genes encoding Glc-signaling proteins have been isolated. However, the full complexity of Glc signaling in higher plants is not yet fully understood. Here, we report the identification and characterization of a new Glc-insensitive mutant, gaolaozhuangren2 (glz2), which was isolated from transposon mutagenesis experiments in Arabidopsis. In addition to its insensitivity to Glc, the glz2 plant exhibits several developmental defects such as short stature with reduced apical dominance, short roots, small and dark-green leaves, late flowering and female sterility. Treatment with 4% Glc blocked expression of the OE33 gene in wild-type plants, whereas expression of this gene was unchanged in the glz2 mutant plants. Taken together, our results suggest that the GLZ2 gene is required for normal glucose response and development of Arabidopsis.Mingjie Chen and Xiaoxiang Xia contributed equally to this work. 相似文献
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Ni Chen Yan Liu Xin Liu Juan Chai Zhong Hu Guangqin Guo Heng Liu 《Plant Molecular Biology Reporter》2009,27(3):321-333