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1.
Adventitious roots were induced from shoots and leaves of the chimera plant TCC (LI-LII-LIII = TCC; T = Tuber mustard, C = Red Cabbage), previously developed by in vitro grafting of tuber mustard (Brassica juncea) and red cabbage (B. oleracea). The regeneration frequency of adventitious roots from TCC shoots and leaf sections was markedly higher than that obtained from the parents TTT (tuber mustard) and CCC (red cabbage). Moreover, levels of α-naphthaleneacetic acid in the culture medium had lower effects on rooting efficiency of TCC chimeras compared to those of TTT and CCC. The number and fresh weight of adventitious roots per TCC shoot, 13.11 roots and 0.274 g, respectively, were also significantly higher than those of the parents. This demonstrated that replacing the histogenic LI layer (the outermost apical cell layer) with a different genotype might improve adventitious root induction capability of these vegetative tissues due to likely synergistic effects between LI and the other two histogenic layers, LII and LIII. Following polymerase chain reaction analysis and histological investigation, it was found that these adventitious roots originated from the LIII histogenic layer.  相似文献   

2.
Zhu XY  Zhao M  Ma S  Ge YM  Zhang MF  Chen LP 《Plant cell reports》2007,26(10):1727-1732
The chimeras between tuber mustard (Brassica juncea) and red cabbage (B. oleracea) were artificially synthesized in our previous study. Adventitious shoots were induced from nodal segments and leaf discs of TCC (LI-LII-LIII, LI -the outmost layer of shoot apical meristem; LII -the middle layer; LIII -the innermost layer. T = Tuber mustard, C = Red cabbage) chimeras. The origin of the shoots was analyzed by histology and molecular biology. As a result, the frequency of adventitious shoot induction rose with the increase of BA in MS medium in the area of the nodes. However, there was no different induction frequency of adventitious shoots from nodal segment bases in media with different BA concentrations. Most adventitious shoots (clustered shoots) arising from the node area were TTT (Tuber mustard- Tuber mustard- Tuber mustard) and only 4 shoots were chimeras, which indicated that more shoots originated from LI than from LII and LIII. All shoots from nodal segment bases were CCC (Red cabbage-Red cabbage- Red cabbage), indicating that the shoots originated from LII or LII and LIII. There were significant differences in the regeneration rate in the margin of the leaf discs among the three combinations of BA and NAA. Most adventitious shoots from the margin of leaf discs were CCC but 2 out of 70 were chimeras, which indicated that more shoots originated from LII or LII and LIII than from LI. All chimeras obtained by regeneration were different from the original explant donor in type in the present study. The origin of the adventitious shoots varied with the site of origin on the donor plant, and could be multicellular and multihistogenic.  相似文献   

3.
The effect of different cadmium concentrations (6–120 μM) on Hill reaction activity (HRA) of isolated chloroplasts, contents of chlorophylls (Chls) and carotenoids (Cars), and Cd uptake and accumulation in plant organs of Indian mustard (Brassica juncea L. cv. Vitasso) and mung bean [Vigna radiata (L.) Wilczek] were determined. The Cd stress inhibited photochemical activity of isolated chloroplasts of both species and in both tested developmental stages. On the basis of EC50 values, the mung bean showed a higher sensitivity to Cd treatment than Indian mustard. The higher sensitivity of both species was determined in the earlier than in the older developmental stage. The leaves of Cd-treated plants possessed lower contents of Chls and Cars in both species and the negative effect increased with Cd concentration. A difference between species was also found in Cd uptake and accumulation. In both species, Cd was accumulated more in roots than in shoots, with higher accumulation in Indian mustard than in mung bean.  相似文献   

4.
In the present investigation, the interspecific somatic hybridization between tuber mustard and red cabbage was established in order to introduce valuable genes from red cabbage (Brassica oleracea) into Brassica juncea. Prior to fusion treatment, protoplasts of red cabbage were inactivated with 2 mM iodoacetamide to inhibit cell division. Micro-calluses were obtained at a frequency of 10.3% after approximately 5 weeks culture following protoplast fusion. Some of the fusion-derived calluses possessed red pigmented cells after being transferred to proliferation medium, and they were presumably considered to be somatic hybrid cell lines. Plantlets were regenerated from 12 cell lines, of which nine plantlets exhibited characteristics intermediate of both parents in terms of plant morphology. With the exception of common protein bands featured by two parents, there were unique banding patterns produced in the hybrids by using SDS-PAGE analysis. By chromosome countings, it was showed that they ranged approximately from 2n=30 to 42 in chromosome numbers. Their hybridity were further confirmed by RAPD analysis revealing that genes of both parents were partially incorporated into the hybrids. Positively, all these hybrids were capable of seed-setting. The pod-setting was 4.2 in somatic hybrid H7 when backcrossed with tuber mustard.  相似文献   

5.
6.
ALBINO3, a homologue of PPF1 in Arabidopsis, encodes a chloroplast protein, and is essential for chloroplast differentiation. In the present study, ALBINO3(−) transgenic plants exhibited a significant decrease in both the number of rosette leaves at bolting and the days before bolting, suggesting the important roles of ALBINO3 in regulating flowering during non-inductive short-day photoperiods. ALBINO3 mRNA was apparently accumulated in shoot apical meristem and floral meristems around the shoot apical meristem in wild-type plants. ALBINO3 might be predominantly involved in inducing the floral repression pathway by activating the expression of TFL1, and by suppressing the expression of LFY, respectively, in the shoot apical meristem. Moreover, the function of ALBINO3 in regulating flowering transition depended on the expression of CO and GA1, because ALBINO3 might function in the downstream integration of the photoperiod-dependent and the photoperiod-independent pathways. These results suggest that ALBINO3 may have an important integrative function in the flowering process in Arabidopsis.  相似文献   

7.
In vitro regeneration of black nightshade (Solanum nigrum L.) plants was achieved through callus-mediated shoot organogenesis followed by 30 d indoor ex vitro adaptation to nutritional stress under environmental ambience and thereafter 6-d outdoor acclimatization in pots prior to field establishment. Relevant physiological parameters including pigment content, chlorophyll a fluorescence, net photosynthetic rate (P N), transpiration rate (E), and stomatal conductance (g s) of in vitro-regenerated plants were investigated during the course of ex vitro adaptation. During the first 4 d of indoor transplantation to potting substrate, there was a marginal reduction in the leaf chlorophyll and carotenoid contents but P N and E were strongly reduced. The stomatal conductance and E/P N ratio were significantly higher in plants up to 20 d of indoor adaptation than those of comparable age grown naturally from seeds. The shape of the OJIP fluorescence transient varied significantly with acclimatization, and the maximum change was observed at 2.0 ms. The 2.0 ms variable fluorescence (V j), 30 ms relative fluorescence (M 0), photon trapping probability (TR0/Abs), and photosystem II (PSII) trapping rate (TR0/RC) showed initial disturbance and subsequent stabilization during 30 d of indoor acclimatization. Energy dissipation (DI0/RC) and electron transport probability (ET0/TR0) showed an initial phase of increase during the 4 d after plants were transplanted outdoors. During the 6-d outdoor acclimatization after transfer of plants to soil, no significant change in total chlorophylls and carotenoids, E, and g s were observed, but P N improved after reduction on the first d. The OJIP-derived parameters experienced change on the first d but were stabilized quickly thereafter. There was no significant difference between outdoor acclimatized plants and those of the seed-grown plants of comparable age with respect to photosynthetic and fluorescence parameters. Direct transfer of plants without indoor acclimatization, however, showed a completely different trend with respect to P N, E, and OJIP fluorescence transients. The bearing of this study on optimizing micropropagation is discussed.  相似文献   

8.
9.
To examine the possible relationship between the activity of 1-aminocyclopropane carboxylic acid synthase (ACS; EC 4.4.1.14) and growth of mustard (Brassica juncea L.), ACS activity, ethylene and plant growth were studied in the presence of ACS activity modulators in no-defoliation and defoliated plants. Growth of plants was greatest when subjected to defoliation of 50% lower leaves in the plant axis compared to defoliation of 25% lower leaves or no-defoliation. The activity of ACS in no-defoliation and defoliated plants was correlative with growth of plants. ACS activity and ethylene evolution in no-defoliation plants treated with 10 μM indole-3-acetic acid (IAA) and defoliated plants treated with water were equal and resulted in maximum plant growth. On the contrary, the application of 10 μM IAA on defoliated plants resulted in the increase in ACS activity and ethylene evolution to an extent that inhibited the growth. The application of 100 μM IAA on no-defoliation and defoliated plants increased ACS activity and ethylene evolution maximally and proved inhibitory for the plant growth. The association of ACS activity, ethylene evolution and growth of plants was further substantiated with the use of 50 μM aminoethoxyvinyl glycine (AVG) applied alone or in combination with 10 or 100 μM IAA. The application of AVG resulted in the inhibition of ACS activity and the growth of no-defoliation or defoliated plants. The results indicate that there exists a correlation between ACS activity, ethylene and the growth of mustard plants.  相似文献   

10.
Trichopus zeylanicus subsp. travancoricus (known as Arogyapacha), an endangered ethnomedicinal plant of the Western Ghats of South India, serves as the major source of the commercial drug Jeevani. The present study established a long-term high frequency in vitro propagation protocol for Arogyapacha. Callus obtained from the branch–petiole explants cultured on Murashige and Skoog (MS) medium with 4.5 μM 2,4-dichlorophenoxyacetic acid upon subculture to medium with different concentrations of 6-benzyladenine (BA) either alone or in combination with an auxin favoured shoot morphogenesis. Medium with 13.3 μM BA alone facilitated high frequency shoot bud (mean of 93.2) formation. Medium with lower concentrations of BA (4.4, 6.6 and 8.8 μM) alone or in combination with lower concentration of α-naphthaleneacetic acid (NAA) or indole-3-butyric acid (IBA) favoured better shoot growth than 13.3 μM BA containing medium, but with reduced number of shoot buds. Subsequent cultures on medium with lower concentrations of BA and also on MS basal media facilitated shoot formation as well as growth of shoots. The shoot regeneration potential showed no decline up to 5 years. Culture of the in vitro-derived whole branch–leaf explants on MS basal medium developed shoots directly from the node. On medium with 19.6 μM IBA, the whole branch–leaf explants induced nodular callus from the node, which developed shoots later. Subsequent cultures on medium with BA exhibited high frequency shoot formation. The transfer of shoots after 10–15 days culture on half-strength MS medium containing 2.7 μM NAA to half-strength basal medium induced a mean of 11.3 roots. Field survival of plantlets relied on the soil mix: a 1:4 ratio of sand and red-soil exhibited the highest plantlets survival (86.6%). RAPD profile of the source plant and plants regenerated from calli after 4 years showed no polymorphism. The established plantlets with morpho-floral features similar to that of the source plants flowered normally and set fruits.  相似文献   

11.
Lettuce plants were treated with gibberellic acid (GA3) and uniconazole (UZ; a gibberellin synthesis inhibitor) to investigate the influence of GA3 on cell division frequency in the shoot apical meristem (SAM) during stem elongation and flower initiation in lettuce (Lactuca sativa) grown in a greenhouse. GA3 (0.1 mM) was sprayed on the surface of outer leaves and uniconazole solution (0.86 mM) was applied to the soil. GA3 increased cell division frequency in the peripheral zone and the rib meristem of shoot apices, and this was associated with the stimulation of stem elongation. UZ treatment decreased cell division frequency in the peripheral zone, rib meristem and subapical pith, and this was associated with restricted stem elongation. Treatment with UZ and GA3 together induced minor stem elongation. Flower induction occurred 3 d earlier in the GA3 and UZ+GA3 treatments than in the control, while the UZ treatment delayed flower initiation for more than 9 d relative to the control.  相似文献   

12.
A protocol for in vitro propagation of the wild germander (Teucrium polium L.) was developed. In vitro plants were developed from ex vitro axillary buds. Then, shoot tips were excised and established on Murashige and Skoog medium. Proliferation of shoots was tested with different levels of 6-furfurylaminopurin, 6-benzyladenine, or thiadiazuron. The highest proliferation of T. polium was obtained when 6-benzyladenine and 6-furfurylaminopurin were used at 2.0 and 1.6 mg l−1, respectively. Thiadiazuron gave the lowest response for shoot proliferation. Rooting was experimented at different levels of Indol-3-butric acid, Indol-3-acetic acid, or 1-naphthaleneacetic acid. 1-Naphthaleneacetic was the only growth regulator which promoted root induction. Rooted plants were acclimatized successfully with 75% survival and grown in the greenhouse. In vitro- and in vivo-grown plants were analyzed for essential oil production. In vitro-grown T. polium on MS medium supplemented with 6-benzyladenine and 1-naphthaleneacetic gave higher oil yield than that grown on hormone-free Murashige and Skoog medium. In vivo (wild)-grown T. polium produced different oil yield when collected in different months (April and October). β-caryophyllene, used as a marker compound in the essential oil, was identified and quantified by gas chromatography (GC) analysis. Gas chromatography/mass (GC-MS) spectrometry analysis was also used to identify other components of in vitro cultures and to compare with in vivo-grown plants.  相似文献   

13.
Camelina [Camelina sativa (L.) Crantz], a member of the Brassicaceae family, has a unique oil profile that has potential both for biofuels and as a food crop. It is essential to have a doubled haploidy protocol in order to enhance breeding of this crop for prairie conditions as well as improve the yield and quality characteristics. Microspore-derived embryos have been produced from Camelina sativa. Buds 1–3 mm in length were selected for culture. The microspores were isolated and purified in full-strength B5 extraction medium and cultured in NLN medium with 12.5% sucrose and 12.5% polyethylene glycol 4000 (PEG) without glutamine, at a density of 10,000 microspores per mL. Glutamine was added to the cultures 72 h after extraction to give a final concentration of 0.8 g/L. The microspore cultures were maintained at 24°C in the dark. After 28 days embryos were observed and these were regenerated to plants and selfed seed was produced. The highest embryogenic frequency achieved was 38 microspore-derived embryos from 100,000 microspores.  相似文献   

14.
We study apical dominance in Alstroemeria, a plant with an architecture very different from the model species used in research on apical dominance. The standard explant was a rhizome with a tip and two vertically growing shoots from which the larger part had been excised leaving ca. 1 cm stem. The axillary buds that resumed growth were located at this 1-cm stem just above the rhizome. They were released by removal of the rhizome tip and the shoot tips. Replacement of excised tips by lanolin with indole-3-butyric acid (IBA) restored apical dominance. The auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and N-1-napthylphthalamic acid (NPA) reduced apical dominance. 6-Benzylaminopurine (BAP) enhanced axillary bud outgrowth but the highest concentrations (> 9 μM) caused fasciation. Thidiazuron (TDZ) did not show improvement relative to BAP. Even though the architecture of Alstroemeria and the model species are very different, their hormonal mechanisms in apical dominance are for the greater part very similar.  相似文献   

15.
Cryopreservation is widely applied to many economically important species excluding chimera plants which are problematic for long-term conservation. Their storage problems can be circumvented only by cryopreserving meristems. This study looked at the morphogenetic response of shoot tips of periclinal chimera chrysanthemum ‘Lady Orange’ and ‘Lady Salmon’, as well as the solid mutant ‘Richmond’, that were cryopreserved by encapsulation-dehydration technique. By applying 10 µM ABA in the preculture medium followed by 4-day-long dehydration treatment, the explant survival reached up to 67%. Besides the stimulation of typical single shoot recovery, cryopreservation led to direct or indirect multiple shoot formation, shoot malformation, as well as inhibited their spontaneous rooting. Microscopic analysis revealed three types of structural damages of shoot tips which can correspond with their morphogenetic response in recovery culture. No influence of cryostorage on the acclimatisation efficiency of the recovered chrysanthemums was observed.  相似文献   

16.
We describe the development of a reporter system for monitoring meristem initiation in poplar using promoters of poplar homologs to the meristem-active regulatory genes WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM). When ~3 kb of the 5′ flanking regions of close homologs were used to drive expression of the GUSPlus gene, 50–60% of the transgenic events showed expression in apical and axillary meristems. However, expression was also common in other organs, including in leaf veins (40 and 46% of WUS and STM transgenic events, respectively) and hydathodes (56% of WUS transgenic events). Histochemical GUS staining of explants during callogenesis and shoot regeneration using in vitro stems as explants showed that expression was detectable prior to visible shoot development, starting 3–15 days after explants were placed onto callus inducing medium. A minority of WUS and STM events also showed expression in the cambium, phloem, or xylem of regenerated, greenhouse grown plants undergoing secondary growth. Based on microarray gene expression data, a paralog of poplar WUS was detectably up-regulated during shoot initiation, but the other paralog was not. Both paralogs of poplar STM were down-regulated threefold to sixfold during early callus initiation. We identified 15–35 copies of cytokinin response regulator binding motifs (ARR1AT) and one copy of the auxin response element (AuxRE) in both promoters. Several of the events recovered may be useful for studying the process of primary and secondary meristem development, including treatments intended to stimulate meristem development to promote clonal propagation and genetic transformation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

17.
The effects of genotype, pollen or growth regulator-pretreatment of pistils, developmental stage of the ovule (embryo sac) and culture media on induction of gynogenesis, and subsequent plantlet regeneration in vitro were assessed in interspecific Gossypium barbadense × G. hirsutum cotton hybrids. Gynogenesis occurred in all genotypes used when the pistils had been pre-treated with pollen from Hibiscus cannabinus and ovaries were harvested 5 or 10 days after anthesis. The use of culture media, SH and MS, showed no significant differences in responding ovules, embryogenic ovules or embryo germination frequency. Recovered progeny were characterized cytogenetically and microscopically to help documenting their reproductive basis. Root tip chromosome counts of 17 plants established from ovule culture revealed that chromosome numbers ranged from 27 to 44. Although the reproductive mechanisms need to be characterized more extensively by cytological and molecular means, the observations suggest that gynogenesis in cotton involves some unusual reproductive events. Aneuploids could be useful for functional genomic characterization of genome shock, deletion mapping, and germplasm introgression.  相似文献   

18.
Gynogenesis was investigated on the allotetraploid Selenicereus megalanthus and the diploid Hylocereus polyrhizus and Hylocereus undatus vine cactus species. Unpollinated ovules from developing flower buds containing microspores at middle uninucleate developmental stage were cultured on MS basal medium containing 2,4-D/TDZ with different sucrose concentrations. Ovule size increased under dark culture conditions in all the three species and the level of response was species and sucrose concentration dependent. The best responses were achieved in the two S. megalanthus accessions, E-123 and J-80, at 0.18 and 0.26 M sucrose. Only ovule enlargement was obtained in H. undatus and both ovule enlargement and callus were obtained in H. polyrhizus. Development in both species ceased and embryoids were not formed. Plant regeneration was directly and indirectly obtained in both S. megalanthus accessions. Ploidy level was determined for a total of 29 S. megalanthus gynogenic plants using flow cytometry: 15 were found to be dihaploid (plants with the gametophytic chromosome number) and the other 14 were found to have higher ploidy levels. This is the first report of successful gynogenesis in Cactaceae. The dihaploids of S. megalanthus successfully produced by ovule culture techniques opens new perspectives in vine cacti breeding.  相似文献   

19.
We have used apical meristem culture to develop an efficient protocol for reducing phytoplasma infection of Artemisia roxburghiana Besser var. purpurascens (Jacq.) Hook. plants. Shoot tips of different sizes from phytoplasma-infected field-grown plants were treated with 0.1% mercuric chloride (HgCl2) for 1 min followed by a 30-s exposure to 70% ethanol. The size of the explants significantly influenced the survival frequency and the success of aseptic culture establishment. Sterile explants responded notably to 13.95 μM Kinetin (Kn) and 0.27 μM α-naphthalene acetic acid (NAA), and a maximum of 38 ± 0.87 shoots per explant could be obtained after 6 weeks of incubation. Sub-culturing of the shoot mass after 8 weeks of culture on the previously described medium to 8.88 μM 6-benzyladenine (BA)- and 0.27 μM NAA-containing medium stimulated further multiplication, elongation and growth of each individual regenerant. Efficient rooting was noted after 5 weeks of transfer on half-strength MS medium containing 4.93 μM IBA. Sequential hardening as hydroponic cultures under culture room and glasshouse conditions led to almost 85 and 98% survival of the regenerants upon transfer to pots and field, respectively. Unlike the original A. roxburghiana plants, the plants raised from tissue culture showed a total absence of inherent phytoplasma infection evaluated via inspection of morphological features, PCR and microscopic observations.  相似文献   

20.
Lisianthus [Eustoma grandiflorum (Raf.) Shinn] is a popular cut flower crop throughout the world, and the demand for this plant for cut flowers and potted plants has been increasing worldwide. Recent advances in genetic engineering have enabled the transformation and regeneration of plants to become a powerful tool for improvement of lisianthus. We have established a highly efficient plant regeneration system and Agrobacterium-mediated genetic transformation of E. grandiflorum. The greatest shoot regeneration frequency and number of shoot buds per explant are observed on media supplemented with 6-Benzylaminopurine (BAP) and α-Naphthalene acetic acid (NAA). We report an efficient plant regeneration system using leaf explants via organogenesis with high efficiency of transgenic plants (15%) in culture of 11 weeks’ duration. Further ectopic expression of two MADS box genes, LMADS1-M from lily (Lilium longiflorum) and OMADS1 from orchid (Oncidium Gower Ramsey), was performed in E. grandiflorum. Conversion of second whorl petals into sepal-like structures and alteration of third whorl stamen formation were observed in the transgenic E. grandiflorum plants ectopically expressing 35S::LMADS1-M. 35S::OMADS1 transgenic E. grandiflorum plants flowered significantly earlier than non-transgenic plants. This is the first report on the ectopic expression of two MADS box genes in E. grandiflorum using a simple and highly efficient gene transfer protocol. Our results reveal the potential for floral modification in E. grandiflorum through genetic transformation.  相似文献   

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