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1.
De novo shoot morphogenesis and plant growth of mustard (Brassica juncea) in vitro in relation to ethylene 总被引:5,自引:0,他引:5
Role of ethylene in de novo shoot morphogenesis from explants and plant growth of mustard ( Brassica juncea cv. India Mustard) in vitro was investigated, by culturing explants or plants in the presence of the ethylene inhibitors aminoethoxyvinylglycine (AVG) and AgNO3 . The presence of 20 μ M AgNO3 or 5 μ M AVG in culture medium containing 5 μ M naphthaleneacetic acid and 10 μ M benzyladenine were equally effective in promoting shoot regeneration from leaf disc and petiole explants. However, AgNO3 greatly enhanced ethylene production which reached a maximum after 14 days, whereas ethylene levels in the presence of AVG remained low during 3 weeks of culture. The promotive effect of AVG on shoot regeneration was overcome by exogenous application of 25 μ M 2-chloroethylphosphonic acid (CEPA), but AgNO3- induced regeneration was less affected by CEPA. For whole plant culture, AVG did not affect plant growth, although it decreased ethylene production by 80% and both endogenous levels of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC by 70–80%. In contrast, AgNO3 stimulated all 3 parameters of ethylene synthesis. Both AgNO3 and CEPA were inhibitory to plant growth, with more severe inhibition occuring in AgNO3 . Leaf discs derived from plants grown with AVG or AgNO3 were highly regenerative on shoot regeneration medium without ethylene inhibitor, but the presence of AgNO3 in the medium was inhibitory to regeneration of those derived from plants grown with AgNO3 . 相似文献
2.
James D. Burton Marianne K. Pedersen Harold D. Coble 《Journal of Plant Growth Regulation》2008,27(4):342-352
Cyclanilide is a plant growth regulator that is registered for use in cotton at different stages of growth, to either suppress
vegetative growth (in combination with mepiquat chloride) or accelerate senescence (enhance defoliation and boll opening,
used in combination with ethephon). This research was conducted to study the mechanism of action of cyclanilide: its potential
interaction with auxin (IAA) transport and signaling in plants. The activity of cyclanilide was compared with the activity
of the auxin transport inhibitors NPA and TIBA. Movement of [3H]IAA was inhibited in etiolated corn coleoptiles by 10 μM cyclanilide, NPA, and TIBA, which demonstrated that cyclanilide
affected polar auxin transport. Although NPA inhibited [3H]IAA efflux from cells in etiolated zucchini hypocotyls, cyclanilide had no effect. NPA did not inhibit the influx of IAA
into cells in etiolated zucchini hypocotyls, whereas cyclanilide inhibited uptake 25 and 31% at 10 and 100 μM, respectively.
Also, NPA inhibited the gravitropic response in tomato roots (85% at 1 μM) more than cyclanilide (30% at 1 μM). Although NPA
inhibited tomato root growth (30% at 1 μM), cyclanilide stimulated root growth (165% of control at 5 μM). To further characterize
cyclanilide action, plasma membrane fractions from etiolated zucchini hypocotyls were obtained and the binding of NPA, IAA,
and cyclanilide studied. Cyclanilide inhibited the binding of [3H]NPA and [3H]IAA with an IC50 of 50 μM for both. NPA did not affect the binding of IAA, nor did IAA affect the binding of NPA. Kinetic analysis indicated
that cyclanilide is a noncompetitive inhibitor of both NPA and IAA binding, with inhibition constants (K
i) of 40 and 2.3 μM, respectively. These data demonstrated that cyclanilide interacts with auxin-regulated processes via a
mechanism that is distinct from other auxin transport inhibitors. This research identifies a possible mechanism of action
for cyclanilide when used as a plant growth regulator. 相似文献
3.
Robert Konieczny Jan Kępczyński Maria Pilarska Danuta Cembrowska Diedrik Menzel Jozef Šamaj 《Journal of Plant Growth Regulation》2009,28(4):331-340
Hypocotyl explants of Mesembryanthemum crystallinum regenerated roots when cultured vertically with either the apical end (AE) or basal end (BE) in media containing indole-3-acetic
acid (IAA). IAA alone induced roots regularly from the basal end of the explants, either from the cut surface immersed in
the medium or from the opposite side. The inhibitors of auxin efflux carriers, α-naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic
acid (TIBA), inhibited rhizogenesis only from AE-cultured explants, indicating the role of polar auxin transport in root regeneration
in this system. Cytokinin (zeatin, kinetin, BAP) added to auxin-containing medium reduced rhizogenesis from the explants maintained
with BE and AE and additionally changed the IAA-induced pattern of rooting in AE-cultured explants by favoring rooting from
the apical end and middle part of the hypocotyl with its concomitant reduction from the basal end. The addition of kinetin
did not influence the content of IAA in the explants maintained with AE, suggesting that the cytokinin effect on root patterning
was not dependent on auxin biosynthesis. Kinetin, however, strongly enhanced ethylene production. The importance of ethylene
in regulating PAT-dependent rhizogenesis was tested by using an ethylene antagonist AgNO3, an inhibitor of ethylene synthesis aminoethoxyvinylglycine (AVG), and a precursor of ethylene, 1-aminocyclopropane-1-carboxylic
acid (ACC). AgNO3 applied together with IAA or with IAA and kinetin strongly reduced the production of ethylene, inhibited rhizogenesis, and
induced nonregenerative callus from BE, suggesting the need for ethylene signaling to elicit the rhizogenic action of auxin.
A reduction of rhizogenesis and decrease of ethylene biosynthesis was also caused by AVG. In addition, AVG at 10 μM reversed
the effect of cytokinin on root patterning, resulting in roots emerging only from BE on the medium with IAA and kinetin. Conversely,
ACC at 200 μM markedly enhanced the production of ethylene and partly mimicked the effect of cytokinin when applied with IAA
alone, thus confirming that in cultured hypocotyls of ice plant, cytokinin affects IAA-induced rhizogenesis through an ethylene-dependent
pathway. 相似文献
4.
Changxi Yin Quanrong Wu Hanlai Zeng Kai Xia Jiuwei Xu Rongwei Li 《Journal of Plant Growth Regulation》2011,30(1):20-29
The dual effects of auxin and ethylene on rice seminal root growth were investigated in this study. Low concentrations of
exogenous indole-3-acetic acid (IAA) had no effect on rice seminal root growth, whereas higher concentrations (≥0.003 μM)
were inhibitory. In contrast, low concentrations of the auxin action inhibitor p-chlorophenoxyisobutyric acid (PCIB), ranging from 0.5 to 50 μM, promoted rice seminal root growth, whereas high concentrations
of PCIB (≥500 μM) and the polar auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) inhibited rice seminal root growth.
These results suggest that endogenous auxin is required but supraoptimal for rapid growth of rice seminal roots. In addition,
although rice seminal root growth was inhibited by the exogenous ethylene-releasing compound ethephon or the ethylene precursor
1-aminocyclopropane-1-carboxylic acid (ACC) as well as exogenous IAA, the 50% inhibition of growth (I50) caused by ethephon or ACC was weakened by certain concentrations of the ethylene action inhibitor Ag+ (0.016-0.4 μM). However, the I50 caused by exogenous IAA was strengthened by Ag+ or the ethylene biosynthetic inhibitor aminoethoxyvinylglycine (AVG) and weakened by certain concentrations of PCIB (0.5-50 μM).
Together, the inhibitory mechanisms of auxin and ethylene on rice seminal root growth should be different, and auxin inhibition
of rice seminal root growth should not be caused by ethylene. Furthermore, our results indicated that a certain threshold
level of ethylene was required to maintain rice seminal root growth, and that ethylene within the threshold may antagonize
auxin inhibition of rice seminal root growth. 相似文献
5.
Lam Hoang Kyung Sik Song In Koo Rhee Jeong Hoe Kim Sangman Lee 《Journal of Plant Biology》2007,50(4):514-516
To analyze the growth inhibitory mechanism of a 2-aminobenzoic acid (2-AA) derived fromBacillus cereus EJ-121, we treatedArabidopsis thaliana plants with 2-AA, 2-AA analogs, auxin (NAA), a known auxin transport inhibitor [2,3,5-triiodobenzoic acid (TIBA)], and an
ethylene action inhibitor [silver thiosulfate (Ag)]. Root development was significantly inhibited by 50 μM 2-AA, whereas the
growth of bacteria and yeast was undeterred. The application of two 2-AA analogs - 3-aminobenzoic acid (3-AA) and 4-aminobenzoic
acid (4-AA) - did not impairArabidopsis root growth at concentrations below 100 μM. These results suggest that the effect of 2-AA is not due to its chemical structure,
but because of its conversion to another metabolite, IAA. To confirm this, we supplemented TIBA in the growth medium, and
found that the degree of inhibition was significantly reduced. Similarly, when plants were co-treated with 100 μM Ag, the
negative effect of 50 μM 2-AA was greatly diminished. All of these observations support the proposal that this inhibition
results from the conversion of 2-AA to IAA. Furthermore, the increased auxin level leads to a rise in ethylene synthesis,
which then blocks root growth and, ultimately, retards overall plant development. 相似文献
6.
A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf
explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl
aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds
were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP, and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot
proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations
of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 μM BAP and 8.5 μM IAA was found
to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation
were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in
half strength MS liquid medium containing different concentrations and combinations of IBA, IAA, and NAA for 4 days, followed
by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l−1 activated charcoal. Elongated shoot treated with 15 μM IBA, 5.7 μM IAA, and 11 μM NAA resulted in highest percent rooting.
The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement
of J. curcas through genetic modification. 相似文献
7.
Phillip A. Wadl Adam J. Dattilo Lisa M. Vito Robert N. Trigiano 《Plant Cell, Tissue and Organ Culture》2011,106(3):513-516
Pityopsis ruthii is an endangered herbaceous perennial species from the United States. In vitro multiplication of this species can be valuable
for germplasm conservation. Flower receptacles of P. ruthii were cultured on Murashige and Skoog medium (MS) supplemented with 11.4 μM indole-3-acetic acid (IAA) in combination with
2.2, 4.4 or 8.8 μM 6-benzyladenine (BA). Shoots were visible within 14–28 days and three plants were successfully rooted on
MS medium supplemented with 5.7 μM IAA. A two tailed t-test for paired-variates revealed that shoot regeneration on MS medium
amended with 11.4 μM IAA and 2.2 μM BA was significantly higher (P < 0.05) than on other treatments. Leaf explants were also cultured on MS not supplemented with growth regulators or supplemented
with 11.4 μM IAA in combination with 0, 2.2, 4.4 or 8.8 μM BA. Shoots were visible within 21–35 days and one plant was successfully
rooted on MS medium supplemented with 5.4 μM NAA. Shoot regeneration on MS medium augmented with 11.4 μM IAA and 2.2 μM BA
was significantly higher (P < 0.05) than the other treatments according to analysis of variance (ANOVA) with a rank transformation. Hyperhydricity and
rooting of shoots was problematic for explants derived from flower receptacles and leaf tissue, but viable plants were regenerated
using both explants sources indicating the potential role for micropropagation in the ex situ conservation of the species. 相似文献
8.
Brassinosteroid (BR) stimulation of auxin-induced ethylene production and the particular step at which BR acts to promote such synthesis were studied in mung bean ( Vigna radiata L. Rwilcz cv. Berken) hypocotyl segments. Increasing concentrations of methionine alone and in combination with 3 μ M BR and 10 μ M IAA had a minimal effect on ethylene production. With increasing concentrations of 1-aminocyclopro-pane-1-carboxylic acid (ACC), however, ethylene production increased. BR or IAA further enhanced ethylene production with maximum rates occurring when these compounds were added together with ACC. The addition of 10 μ M CoCl2 in conjunction with BR and/or IAA resulted in 85–97% inhibition of ethylene production. When 20 μ M cycloheximide was used in conjunction with BR and/or IAA there was a complete inhibition of ethylene production. Total inhibition also resulted when 1.0 μ M aminoethoxy-vinylglycine (AVG) was used in combination with BR and/or IAA. AVG alone had no effect on ACC conversion to ethylene. 相似文献
9.
Huabing Meng Shujin Hua Imran Haider Shamsi Ghulam Jilani Yuanlong Li Lixi Jiang 《Plant Growth Regulation》2009,58(1):47-59
Because of its prolific growth, oilseed rape (Brassica napus L.) can be grown advantageously for phytoremediation of the lands contaminated by industrial wastes. Therefore, toxic effect
of cadmium on the germination of oilseed rape, the capability of plants for cadmium phytoextraction, and the effect of exogenous
application of plant growth regulators to mitigate phytotoxicity of cadmium were investigated. For the lab study of seedlings
at early stage, seeds were grown on filter papers soaked in different solutions of Cd2+ (0, 10, 50, 100, 200 and 400 μM). In greenhouse study, seedlings were grown in soil for 8 weeks, transferred to hydroponic
pots for another 6 weeks growth, and then treated with plant growth regulators and cadmium. Four plant growth regulators viz.
jasmonic acid (12.5 μM), abscisic acid (10 μM), gibberellin (50 μM) and salicylic acid (50 μM); and three levels of Cd2+ (0, 50 and 100 μM) were applied. Data indicated that lower concentration of Cd2+ (10 μM) promoted the root growth, whereas the severe stresses (200 or 400 μM) had negative effect on the establishment of
germinating seedlings. Plants treated with any of the tested plant growth regulators alleviated cadmium toxicity symptoms,
which were reflected by more fresh weight, less malondialdehyde concentration in leaves and lower antioxidant enzyme activities.
The application of abscisic acid to the plants cultivated in the medium containing 100 μM Cd2+ resulted in significantly lower plant internal cadmium accumulation.
Huabing Meng and Shujin Hua contributed equally to this paper. 相似文献
10.
Cooperation of Ethylene and Auxin in the Growth Regulation of Rice Coleoptile Segments 总被引:2,自引:0,他引:2
Elongation of coleoptile segments, having or not having a tip,excised from rice (Oryza sativa L. cv. Sasanishiki) seedlingswas promoted by exogenous ethylene above 0.3 µl l1as well as by IAA above 0.1 µM. Ethylene production ofdecapitated segments was stimulated by IAA above 1.0µM,and this was strongly inhibited by 1.0 µM AVG. AVG inhibitedthe IAA-stimulated elongation of the decapitated segment witha 4 h lag period, and this was completely recovered by ethyleneapplied at the concentration of 0.03 µl l1, whichhad no effect on elongation without exogenous IAA. The effectsof IAA and ethylene on elongation were additive. These factsshow that ethylene produced in response to IAA promotes ricecoleoptile elongation in concert with IAA, probably by prolongingthe possible duration of the IAA-stimulated elongation, butthat they act independently of each other. Moreover, AVG stronglyinhibited the endogenous growth of coleoptile segments withtips and this effect was nullified by the exogenous applicationof 0.03 µl l1 ethylene. These data imply that theelongation of intact rice coleoptiles may be regulated cooperativelyby endogenous ethylene and auxin in the same manner as foundin the IAA-stimulated elongation of the decapitated coleoptilesegments. Key words: oryza sativa, Ethylene, Auxin, Coleoptile growth 相似文献
11.
Purified malformin A1 (cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-lle), a cyclicpentapeptide toxin fromAspergillus niger, was applied to the hypocotyl segments of mung bean (Vigna radiata L.) seedlings to investigate its role in regulating ethylene biosynthesis. Production of ethylene was induced by treating
the plants with 0.1 mM indole-3-acetic acid (1AA). When 0.1 μM malformin A1 was then applied, ethylene production increased
and the activities of two key enzymes for its biosynthesis, 1-aminocyclopropane-1-carboxylic acid (ACC)-synthase (ACS) and
ACC-oxidase (ACO), were also stimulated. However, at levels of 1 or 10 μM malformin A1, both ethylene production and enzymatic
activities were significantly reduced. In the case of ACO,in vitro activity was regulated by malformin A1, independent of ACS activity or the influence of IAA. Furthermore, the conjugate form
of ACC, N-malonyl ACC, was significantly promoted by treatment with 0.1 μM malformin A1. These data suggest that malformin
A1 can modulate ethylene production through diverse paths and that its effect depends on the concentration of the treatment
administered. 相似文献
12.
13.
Propagation by softwood canes and cuttings is preferred as a practical system for vegetative reproduction of many ornamental
plant species, despite the advances in tissue culture techniques. Dracaena purplecompacta L. is a species that has a high demand for exports. Conversely, coconut water (CW) is a rich supplement that naturally contains
plant growth regulators such as indole acetic acid (IAA). The objective of this work was to evaluate the potential of CW extracts
containing natural IAA, on adventitious root development in vegetative propagation of ornamental plant canes of D. purplecompacta L. Five different concentrations (28, 57, 143, 286, 571 μM of natural IAA) of CW extracts were tested. Another set of treatment
was carried out with the same concentrations of authentic IAA hormone for comparison purpose. The 143-μM IAA CW extract recorded
the best root induction and development. It was found that the root expression was faster (5 weeks) with the use of the novel
method. In the conventional method, the canes are propagated by quick dip application of commercial product containing artificial
hormone IAA and placing them on coir fiber dust beds. It takes up to 6 weeks for the canes to develop adventitious roots to
the desired level. Steeping canes in 143-μM IAA CW extract improved rooting in D. purplecompacta L., and it was comparable to the application of 143-μM authentic IAA. The study indicates that adventitious root development,
shoot development, and leaf emergence of D. purplecompacta L. is promoted by IAA CW extracts. 相似文献
14.
In the zucchini squash, Cucurbita pepo, a well coordinated abscission of the female flower during fruit set is essential to obtain a fruit of commercial value.
In Spain zucchini is mainly produced in greenhouses in Almería, where high temperatures during the spring-summer period provoke
a cultivar-dependent defect in fruits known as the “sticky flower” syndrome. This disorder is characterised by an arrest in
growth and maturation of floral organs, and a lack of female floral abscission, thus diminishing fruit shelf-life, commercial
quality and value. The aim of the present work was to improve knowledge of the abscission process in C. pepo to better understand the fundamental causes of this disorder. The anatomical analysis of abscission shows a well defined
male floral abscission zone (AZ), few hours after anthesis, which differs from the female zone which is not differentiated
from the adjacent tissue until the abscission process has begun, and which occurs as a consequence of AZ cell enlargement
and the dissolution of their cell walls. To evaluate the role of ethylene and auxins in the regulation of floral abscission
in zucchini we performed several treatments, with: ethylene, added as 0.25% ethrel solution; AVG, the inhibitor of ethylene
synthesis, at 100 μM; indol-3-acetic acid, 100 μM; and TIBA, the inhibitor of auxin polar transport, at 10 mM. These treatments
show that ethylene is an accelerator of zucchini floral abscission, and also promotes abscission in isolated AZs of sticky
flowers. On the other hand, IAA delays abscission of the female flowers, whilst the inhibitor of auxin polar transport promotes
it. The activity of the cell wall hydrolytic enzymes, polygalacturonase and cellulase, sharply increased just before the shedding
of zucchini floral organs (72 h after anthesis). Moreover, both enzyme activities were induced by ethylene, which partly explains
the ethylene promoting effect. 相似文献
15.
Savita Gangwar Vijay Pratap Singh Sheo Mohan Prasad Jagat Narayan Maurya 《Acta Physiologiae Plantarum》2011,33(2):451-462
Present study showed the responses of pea seedlings to exogenous indole acetic acid (IAA; 10 and 100 μM) application under
manganese (Mn; 50, 100 and 250 μM) toxicity. Manganese and 100 μM IAA alone as well as in combination decreased growth of
pea seedlings compared to control. Moreover, some parameters of oxidative stress—hydrogen peroxide (H2O2) and malondialdehyde (MDA) were also increased by single and combined treatments of Mn and 100 μM IAA compared to control.
In contrast, addition of 10 μM IAA together with Mn, alleviated Mn toxicity symptoms and promoted growth led to the decrease
in H2O2 and MDA levels compared to Mn treatments alone. Under single and combined treatments of Mn and 100 μM IAA, catalase activity
decreased while superoxide dismutase and ascorbate peroxidase activities increased and glutathione reductase and dehydroascorbate
reductase exhibited differential responses. However, addition of 10 μM IAA together with Mn, increased activities of studied
enzymatic antioxidants. Root and shoot reduced ascorbate (AA) and reduced glutathione (GSH) and, their reduced/oxidized ratios
decreased while dehydroascorbate (DHA) and oxidized glutathione (GSSG) contents increased compared to control following single
and combined treatments of Mn and 100 μM IAA. However, supply of 10 μM IAA together with Mn, increased AA and GSH, and their
reduced/oxidized ratios in root and shoot compared to Mn treatments alone. This study thus suggests that 10 μM of IAA was
able to increase Mn tolerance in pea seedlings under Mn toxicity while opposite was noticed for 100 μM IAA. 相似文献
16.
Phenylacetic acid (PAA) was found to induce ethylene formation in wheat coleoptile segments. In its most effective concentration
(0.5 mM) PAA was by approximately 60 % less active than 0.1 mM indole-3-acetic acid (IAA). PAA-induced ethylene formation
was stimulated with 0.1 mM L-methionine by 24 % and totally inhibited by 2.5 and 5 μ gml-1 aminoethoxyvinylglycin (AVG) and 10 μg ml-1 cycloheximide. Cyoloheximide in lower concentration (5 μg ml-1) and actinomycin D (10 μg ml-1) inhibited PAA-induced ethylene formation by 50 % and 40 %, respectively.
After the simultaneous addition of PAA and IAA ethylene formation was by 35 % lower than in the presence of IAA itself. Further,
the coleoptile segments preincubated in IAA and then incubated in PAA solution produced by 35 % less ethylene than those incubated
in plain buffer after preincubation in IAA. Quite the opposite effect was found when the segments were preincubated in PAA
and then transferred into IAA solution. This treatment resulted in 70 % stimulation of ethylene formation over segments preincubated
in PAA and incubated in buffer. 相似文献
17.
Hannibal T. Musarurwa Johannes van Staden Nokwanda P. Makunga 《Plant Growth Regulation》2010,61(3):287-295
The aromatic medicinal plant Salvia stenophylla contains α-bisabolol, making this plant an important contributor to the aromatherapy and cosmetic industries in South Africa.
Due to its commercial importance, the cultivation of this plant using an in vitro system was considered. Firstly, seedlings
were raised in vitro after breaking dormancy with light, smoke-water or chemical scarification treatments. Germination improved
when seeds were smoke-treated or soaked in 70% (v/v) H2SO4. Vigorous plantlet regeneration was achieved when seedling explants were cultured on Murashige and Skoog (1962) medium with 5.7 μM IAA and 8.9 μM BA. The potential regeneration capacity for this protocol was estimated and over 1,000
plantlets can be produced from a single shoot (6.67 cm with 4–6 nodes) over a period of 3 months. Plants rooted easily regardless
of their growth medium. This was followed by their successful rapid establishment and normal growth out of culture (75%).
Finally, the volatile compounds in in vitro plants were compared to ex vitro plants via headspace solid phase microextraction
linked to gas chromatography–mass spectrometry. The chemical complexity of microplants was similar to wild plants with in
vitro plants continuing to produce α-bisabolol (21%) at high levels. 相似文献
18.
Landi Sun Suiwen Hou Dali Wu Yingcong Zhang 《In vitro cellular & developmental biology. Plant》2008,44(5):396-400
This study describes a reliable protocol for callus induction and rapid mass propagation of the ecologically important plant,
Zygophyllum xanthoxylon (Bunge) Maxim. The optimum callus induction medium was Murashige and Skoog (MS) supplemented with 4.4 μM 6-benzylaminopurine
(BAP) and 2.7 μM α-naphthalene–acetic acid (NAA), on which the callus induction frequencies from different seedling explants
were all 100%. However, seedling-derived callus did not form regenerated shoots. In order to achieve shoot multiplication,
shoots were developed from cultured plumules, at an average of 3.1 shoots per explant, and the regenerated shoot tips were
further multiplied by subculture. The best shoot multiplication from shoot tips was achieved on MS supplemented with 5.4 μM
NAA and 22.2 μM BAP after 40 d of culture. Seventy-three percent of regenerated shoots formed roots when cultured on MS supplemented
with 8.6 μM IAA after 4 wk of culture. The plants that acclimatized successfully in sand flourished the following year, with
normal morphology and growth characteristics. 相似文献
19.
Lourdes Castelblanque Begoña García-Sogo Benito Pineda Vicente Moreno 《Plant Cell, Tissue and Organ Culture》2010,100(1):107-112
A simple and efficient protocol for plant regeneration from protoplasts of the potted plant Kalanchoe blossfeldiana Poelln. is reported. Mesophyll protoplasts were isolated from axenic leaves after a preculture. The enzymatic digestion of
the tissue with a solution containing 0.4% Cellulase Onozuka R-10 and 0.2% Driselase yielded 6.0 × 105 protoplasts per gram fresh weight after density gradient purification. Protoplasts were cultured in the dark at an initial
density of 1 × 105 protoplasts per milliliter in a liquid medium with 320 mM mannitol, 130 mM sucrose, 2.3 μM 2,4-dichlorophenoxy acetic acid
(2,4-D), 5.4 μM 1-naphthaleneacetic acid (NAA) and 2.2 μM 6-benzyladenine (BA). Cell wall regeneration was observed within
4 days of culture and cell division began after 5–7 days. When cultured in a liquid medium with 5.4 μM NAA and 8.9 μM BA,
protoplast-derived colonies proliferated until small visible calli, and adventitious buds appeared after transfer to photoperiod
conditions. Developed shoots were rooted on a solid medium supplemented with 0.6 μM indole-3-acetic acid (IAA) and successfully
established under greenhouse conditions. The process required 4 months from isolation to rooted plants and the best conditions
found gave a plant regeneration efficiency of 6.4 plants per 1 × 105 protoplasts. This is the first protocol reported for plant regeneration from protoplasts for a Crassulaceae family species. 相似文献
20.
Jin-Ha Jeong Young-Dong Jeon O-Mi Lee Jeong-Do Kim Na-Ri Lee Geun-Tae Park Hong-Joo Son 《Biodegradation》2010,21(6):1029-1040
In this study, we isolated and characterized a novel feather-degrading bacterium that shows keratinolytic, antifungal and
plant growth-promoting activities. A bacterium S8 was isolated from forest soil and confirmed to belong to Bacillus subtilis by BIOLOG system and 16S rRNA gene analysis. The improved culture conditions for the production of keratinolytic protease
were 0.1% (w/v) sorbitol, 0.3% (w/v) KNO3, 0.1% (w/v) K2HPO4, 0.06% (w/v) KH2PO4 and 0.04% (w/v) MgCl2·6H2O (pH 8.0 and 30°C), respectively. In the improved medium containing 0.1% (w/v) feather, keratinolytic protease production
was around 53.3 ± 0.3 U/ml at 4 day; this value was 10-fold higher than the yield in the basal feather medium (5.3 ± 0.1 U/ml).
After cultivation for 5 days in the improved medium, intact feather was completely degraded. Feather degradation resulted
in free –SH group, soluble protein and amino acids production. The concentration of free –SH group in the culture medium was
15.5 ± 0.2 μM at 4 days. Nineteen amino acids including all essential amino acids were produced in the culture medium; the
concentration of total amino acid produced was 3360.4 μM. Proline (2809.9 μM), histidine (371.3 μM) and phenylalanine (172.0 μM)
were the major amino acids released in the culture medium. B. subtilis S8 showed the properties related to plant growth promotion: hydrolytic enzymes, ammonification, indoleacetic acid (IAA),
phosphate solubilization, and broad-spectrum antimicrobial activity. Interestingly, the strain S8 grown in the improved medium
produced IAA and antifungal activity, indicating simultaneous production of keratinolytic and antifungal activities and IAA
by B. subtilis S8. These results suggest that B. subtilis S8 could be not only used to improve the nutritional value of feather wastes but also is useful in situ biodegradation of
feather wastes. Furthermore, it could also be a potential biofertilizer or biocontrol agent applicable to crop plant soil. 相似文献