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1.
A full-length cDNA of the gene for phytochrome A from Arabidopsis thaliana was fused with the 35S promoter of cauliflower mosaic virus (CaMV35S-PHYA) and introduced into horseradish (Armoracia rusticana Gaert., Mey. et Scherb.) hairy roots. The phytochrome level in hairy roots transformed with CaMV35SPHYA was about three times greater than that in normal hairy roots and the rate of light-induced formation of adventitious shoots
was also higher in the hairy roots transformed with CaMV35SPHYA. These results indicate that the light-induced formation of adventitious shoots on horseradish hairy roots is closely related
to the phytochrome level.
Received: 11 August 1998 / Revision received: 21 October 1998 / Accepted: 20 November 1998 相似文献
2.
Tsutomu Saitou Yoshinobu Tachikawa Hiroshi Kamada Masakatsu Watanabe Hiroshi Harada 《Planta》1993,189(4):590-592
An action spectrum was determined for lightinduced formation of adventitious shoots in hairy roots of horseradish (Armoracia rusticana Gaert., Mey. et Scherb.) cultured in vitro. Near ultraviolet (350–400 nm), blue (440–460 nm) and red light (600–680 nm) were most effective in inducing formation of adventitious buds. Farred light (730 nm) inhibited the promotive effect of all three wavelength regions. These results are consistent with induction by phytochrome(s) of adventitious shoots in hairy roots of horseradish. 相似文献
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Psoralea corylifolia is an endangered plant producing various compounds of medical importance. Adventitious roots and hairy roots were induced
in cultures prepared from hypocotyl explants. Psoralen content was evaluated in both root types grown either in suspension
cultures or on agar solidified medium. Psoralen content was ~3 mg g−1 DW in suspension grown hairy roots being higher than in solid grown hairy roots and in solid and suspension-grown adventitious
roots. 相似文献
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Scott E. Hyndman Paul M. Hasegawa Ray A. Bressan 《Plant Cell, Tissue and Organ Culture》1981,1(1):229-238
Cultured shoots ofRosa ‘Improved Blaze’ were used to determine the effects of sucrose and inorganic nitrogen on adventitious root formation. Shoots
grown in media containing high sucrose concentrations (146.07–262.93 mM) produced more and longer roots than those grown in media containing 0–87.64 mM sucrose. This response to sucrose was related to the metabolism of sucrose rather than its osmotic properties since the use
of mannitol and 3-O-methyl-α-D-glucopyranoside as osmotic substitutes did not reproduce the effect on rooting. The number
and length of roots increased when the shoots were grown in media with the nitrogen concentration of the Murashige-Skoog (MS)
salt formulation reduced from 60 to 7.5 mM. Neither nitrate (NO
3
−
) nor ammonium (NH
4
+
) alone at any of the concentrations tested had the effect on rooting that both had together in the ratio of the MS salt formulation.
When the sucrose and nitrogen concentrations were both varied, the greatest rate of root initiation occurred on shoots grown
in media with a high sucrose to nitrogen concentration ratio. 相似文献
7.
Hydrogen peroxide (H2O2), an active oxygen species, is widely generated in many biological systems. The present study demonstrates that H2O2 was generated in seedling explants after the primary roots were removed, and it mediates the auxin response prior to adventitious
root formation in cucumber (Cucumis sativus L. Ganfeng 8). When compared with the controls, treatment of cucumber seedling explants after primary roots removal with
either 20–40 mM H2O2 or 10 μM IAA significantly increased the number of adventitious roots, and treatment with 10–50 mM H2O2 significantly increased the fresh weight of adventitious roots. The effects of H2O2 on promoting the formation and growth of adventitious roots were eliminated by 2 mM ascorbic acid, 100 U CAT or 1 μM DPI,
and the effects of IAA were eliminated by 4 mM ascorbic acid, 100 U CAT or 5 μM DPI. Treatment with either 4 mM ascorbic acid
or 1–5 μM DPI inhibited the formation and growth of adventitious roots, and these inhibitory effects were partly reversed
by exogenous H2O2.Furthermore, a higher concentration of endogenous H2O2 was detected in seedling explants 3 h after the primary roots were removed. However, in 10 μM DPI-treated seedling explants,
the concentration of endogenous H2O2 was markedly reduced by DPI. Results obtained suggest that H2O2 may function as a signaling molecule, involved in the formation and development of adventitious roots in cucumber. 相似文献
8.
Carnation plantlets (Dianthus caryophyllus L.) cultured in vitro often develop morphological and physiological anomalies, a phenomenon called hyperhydricity, which impairs their survival
ex vitro. When the agar concentration of the growth medium was increased (from 0 to 12 g dm−3), thereby reducing water availability, the hyperhydricity of those adventitious shoots regenerated from carnation petals
decreased. This was accompanied by a progressive fall in the water content of shoots (94.9 to 91.4 %), fresh mass (from 57.2
to 1.8 mg), number of leaf parenchyma cell layers (from 9.3 to 7.7), and the size of these cells (from 968 to 254 μm2). However, the number of regenerated shoots also decreased (17.7 in 2 g dm−3 agar to 4.3 in 12 g dm−3). Similarly, in ventilated tubes, which exhibit a lower relative humidity than tightly closed tubes, shoot organogenesis
diminished up to 28 %, in tandem with shoot water content. Thus, relative humidity and water availability in culture vessels
do not only influence shoot hyperhydricity in carnations, but also greatly affect adventitious shoot organogenesis. 相似文献
9.
Ethylene accumulation in waterlogged Rumex plants promotes formation of adventitious roots 总被引:8,自引:0,他引:8
Visser Eric J.W.; Bgemann Gerard M.; Blom Cornelis W.P.M.; Voesenek Laurentius A.C.J. 《Journal of experimental botany》1996,47(3):403-410
Accumulation of the gaseous plant hormone ethylene is very importantfor the induction of several responses of plants to flooding.However, little is known about the role of this gas in the formationof flooding-induced adventitious roots. Formation of adventitiousroots in Rumex species is an adaptation of these plants to floodedsoil conditions. The large air-spaces in these roots enablesdiffusion of gases between shoot and roots. Application of ethylene to non-flooded Rumex plants resultedin the formation of adventitious roots. In R. palustris Sm.shoot elongation and epinasty were also observed. The numberof roots in R. thyrsiflorus Fingerh. was much lower than inR. palustris, which corresponds with the inherent differencein root forming capacity between these two species. Ethyleneconcentrations of 1.52µI I 1 induced a maximumnumber of roots in both species. Quantification of ethylene escaping from root systems of Rumexplants that were de-submerged after a 24 h submergence periodshowed that average ethylene concentrations in submerged rootsreached 1.8 and 9.1 µl I1 in R. palustris and R.thyrsiflorus, respectively. Inhibition of ethylene productionin R. palustris by L--(2-aminoethoxyvinyl)-glycine (AVG) or-aminobutyric acid (AIB) decreased the number of adventitiousroots induced by flooding, indicating that high ethylene concentrationsmay be a prerequisite for the flooding-induced formation ofadventitious roots in Rumex species. Key words: Adventitious roots, epinasty, ethylene, flooding, Rumex, shoot elongation 相似文献
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H. D. Cooper D. T. Clarkson M. G. Johnston J. N. Whiteway B. C. Loughman 《Plant and Soil》1986,91(3):319-322
Summary One part of a split root system of wheat seedlings received full nutrient solution with15N-nitrate, the other received an identical solution with unlabelled nitrate. Appearance of labelled amino compounds was measured in the xylem sap exuding from roots not supplied directly with15N-nitrate after removal of the15N-nitrate-fed roots. This material indicates cycling of nitrogen from the shoots and through the roots. About 60 per cent of the nitrogen in the xylem appears to be cycling in this way. 相似文献
12.
Geert-Jan de Klerk Wim van der Krieken Joke C. de Jong 《In vitro cellular & developmental biology. Plant》1999,35(3):189-199
Summary Considerable progress has recently been made in understanding adventitious root formation using physiological studies. It
is recognized that rooting is a process consisting of distinct phases, each with its own requirements. In this review, the
successive phases in the rooting process are described and the possible roles of wounding-related compounds, auxin, ethylene
and phenolic compounds during these specific phases are discussed. Recent results are assisting the development of advanced
rooting treatments. Molecular studies on rooting are underway and will be essential in revealing the mechanisms underlying
adventitious root formation. 相似文献
13.
Light effects on in vitro adventitious root formation in axillary shoots of a 95-year-old black cherry ( Prunus serotina Ehrh.) were examined using microcuttings derived from cultured vegetative buds. Three studies were performed: 1) complete darkness and 4 levels of continuous white light irradiance were tested at 70, 278, 555 and 833 μmol m−2 s−1 ; 2) white, red, yellow and blue light were tested to assess the importance of spectral quality; and 3) the effect of blue light at intensities of 7,15, 22 and 30 μmol m−2 s−1 was also studied, Measurements included rooting percentage, total number of roots per shoot, and shoot and root dry weight. There was a strong negative effect of white light intensity upon root formation. Blue light between 15 and 22 μmol m−2 : s−1 significantly retarded root formation and completely inhibited it at 36 μmol m−2 s−1 . Shoots treated with yellow light exhibited the highest rooting percentage, mean number of roots per shoot, and root dry weight. 相似文献
14.
马尾松( Pinus massoniana)组织培养生根困难,该研究在严格控制光温条件的光照培养中,以马尾松无性系组培继代芽为材料,分析了在不同温度处理下马尾松组培单芽生根率、生根时间、根系条数和移栽成活率等生根能力指标以及生根解剖构造的变化。所有数据均采用SPSS 19.0统计分析软件,进行单因素分析(ANOVA)的显著性检验及最小显著性差异法(LSD)的多重比较。结果表明:在25℃最适温度培养下,马尾松组培生根效果较佳,移栽成活率最高,可达98.1%。低温处理下,生根时间显著延长,根系条数减少,生根率偏低;高温处理下,根茎愈伤组织明显,移栽成活率显著降低。从生根解剖构造来看,马尾松不定根主要由维管形成层细胞分化而成。与25℃适温处理相比较,在20℃较低温处理下,细胞分裂活动缓慢,不定根原始体诱发较少;而在30℃较高温处理下,细胞活动旺盛,但髓射线与维管组织细胞染色颜色加深、排列紧密,将诱发的不定根原基细胞团区隔成带状或片状。该研究结果探讨了培养环境温度对马尾松组培单芽生根能力的影响,为马尾松组培苗生产提供了参考。 相似文献
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Anne -Claire van Altvorst Svetla Yancheva Hans Dons 《Plant Cell, Tissue and Organ Culture》1995,40(2):151-157
Adventitious shoot formation was studied with leaf, stem and axillary bud explants of carnation (Dianthus caryophyllus L.). The shoot regeneration procedures were applicable for a wide range of cultivars and shoot regeneration percentages were high for all explant types. Using axillary bud explants, shoot regeneration efficiency was independent of the size of the bud and of its original position in the plant. In contrast, shoot regeneration from stem and leaf explants was strongly dependent on their original position on the plant. The most distal explants (just below the apex) showed the highest level of shoot regeneration. The adventitious shoot primordia developed at the periphery of the stem segment and at the base of leaf explants. In axillary bud, stem and leaf explants, shoot regeneration originated from node cells, located at the transition area between leaf and stem tissue. Moreover, a gradient in shoot regeneration response was observed, increasing towards the apical meristem.Abbreviations BA
benzyladenine
- NAA
naphthaleneacetic acid 相似文献
18.
In our investigation, auxins (IAA, IBA and NAA) effectively promoted rooting in soybean hypocotyls. The activity of anionic
peroxidase (POX) (pI 3.7) and cationic POX (pI 8.5) was significantly suppressed by exogenous auxins on day 2 (the inductive
phase). Some particular anionic POXs (pI 4.0 and pI 5.3) significantly increased in IBA-treated tissues as compared with the
control when the incubation time was prolonged to day 3 and day 4 (the initiation phase). We sequenced 5′-flanking region
of pI 8.5 and pI 5.3 POX genes using the PLACE and PlantCARE databases to identify several potential cis-regulatory elements. The pI 8.5 POX gene promoter contained two sites that were homologous to sequences commonly found in
auxin response elements; motifs ARF/AuxRE and CATATGGMSAUR. During the inductive phase, the activity of pI 8.5 POX was significantly
suppressed by the exogenously applied auxins. The pI 8.5 POX gene promoter contained both ARF/AuxRE and CATATGGMSAUR motifs
that responded to auxins earlier than the pI 5.3 POX gene. Hence, the pI 8.5 POX gene might belong to primary auxin response
genes. The pI 5.3 POX gene, which responded to auxins a day or two later, contained only ARF/AuxRE motif. Moreover, unlike
pI 8.5 and pI 3.7 POXs that were suppressed by auxins, the pI 5.3 POX was induced or enhanced by the applied auxins, especially
IBA. The pI 5.3 POX might generate H2O2 which caused the auxin-induced growth at the initiation phase during the formation of adventitious root in soybean hypocotyls. 相似文献
19.
BACKGROUND AND AIMS: Aerenchyma formation is thought to be one of the important morphological adaptations to hypoxic stress. Although sponge gourd is an annual vegetable upland crop, in response to flooding the hypocotyl and newly formed adventitious roots create aerenchyma that is neither schizogenous nor lysigenous, but is produced by radial elongation of cortical cells. The aim of this study is to characterize the morphological changes in flooded tissues and the pattern of cortical aerenchyma formation, and to analyse the relative amount of aerenchyma formed. METHODS: Plants were harvested at 16 d after the flooding treatment was initiated. The root system was observed, and sections of fresh materials (hypocotyl, tap root and adventitious root) were viewed with a light or fluorescence microscope. Distributions of porosity along adventitious roots were estimated by a pycnometer method. KEY RESULTS: Under flooded conditions, a considerable part of the root system consisted of new adventitious roots which soon emerged and grew quickly over the soil surface. The outer cortical cells of these roots and those of the hypocotyl elongated radially and contributed to the development of large intercellular spaces. The elongated cortical cells of adventitious roots were clearly T-shaped, and occurred regularly in mesh-like lacunate structures. In these positions, slits were formed in the epidermis. In the roots, the enlargement of the gas space system began close to the apex in the cortical cell layers immediately beneath the epidermis. The porosity along these roots was 11-45 %. In non-flooded plants, adventitious roots were not formed and no aerenchyma developed in the hypocotyl or tap root. CONCLUSIONS: Sponge gourd aerenchyma is produced by the unique radial elongation of cells that make the expansigeny. These morphological changes seem to enhance flooding tolerance by promoting tissue gas exchange, and sponge gourd might thereby adapt to flooding stress. 相似文献
20.
The development of adventitious shoots of Picea abies was affected by the agar concentration in the culture medium. Increasing the agar concentration from 0.5 to 2.0% decreased vitrification, but at the same time reduced shoot growth and rooting potential. Slightly vitrified plantlets could become acclimatized to greenhouse conditions. The mesophyll of needles developed in vitro was interspersed with large air spaces; the lower the agar concentration, the larger the air spaces. After transfer to the greenhouse, the new needles from the acclimatized plantlets had an anatomy approaching that of plants growing in field. 相似文献