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1.
Germination, or outgrowth, of Myriophyllum verticillatum turions involves a series of visible changes starting with reflexing of leaves followed by extension and curving of the axis, and then by root formation. Before abscission, turions grow out in response to long days (16 hr) but not short days (8 hr). After abscission, turions show maximal dormancy which can be fully broken by a cold treatment (4 C). Turions are heterogeneous in degree of dormancy and ability to respond to less complete dormancy-breaking treatments, e.g., long days at 20 C. Cytokinins (10-6 m) break dormancy of non-cold-treated turions, whereas gibberellic acid (GA3) is ineffective except at high concentrations (10-3 m). Continuous treatment with cytokinins causes abnormal development after germination. GA3, on the other hand, induces apparently normal development even at high concentration. Indoleacetic acid (IAA) induces outgrowth only at high concentrations (10-3 - 10-4 m), but these concentrations also produce abnormal development. Abscisic acid (ABA, 10-5 m) retards outgrowth of cold-treated turions and can completely suppress it in non-cold-treated turions. The activity of ABA-like substances in turions remains about the same before and during germination, whereas other (unidentified) acidic inhibitors decrease markedly. The cytokinin activity changes in a complex pattern. 相似文献
2.
L. Adamec 《Biologia Plantarum》2003,47(3):395-402
Two main dormancy states, innate and imposed dormancy, were characterized in turions (winter buds) of the aquatic carnivorous plant Aldrovanda vesiculosa L. (Droseraceae) kept at 3 ± 1 °C in a refrigerator over the winter. As a result of the breaking of imposed dormancy by a temperature increase (at 15 – 20 °C), some of the turions rose to the water surface within 1 – 3 d and germinated. Turion leaves contained large lacunae with a slimy reticulum and were filled by water over winter. As a result of breaking imposed dormancy, the proportion of gas volume in inner turion leaves rose from 10 – 20 % to 100 % of leaf lacunae volume. The aerobic dark respiration rate of the turions [0.74 – 1.5 μmol O2) kg−1(FM) s−1] slightly increased during innate dormancy after 1 – 2 d at 20 °C, while it was almost constant during the breaking of imposed dormancy. The anaerobic fermentation rate of the turions was only 1.5 – 7 % of the oxygen respiration rate and also was constant during the breaking of imposed dormancy. In turions, the content of glucose, fructose, and sucrose was the same for the two states of dormancy, but starch content was greatly reduced for the imposed dormancy (10 – 11 vs. 32 % DM). It may be suggested that a temperature increase causes an increase of fermentation or respiration which is responsible for the evolution of gas in turion lacunae and, thus, for turion rising. 相似文献
3.
Effects of gibberellin and auxin on the synthesis of abscisic acid and ethylene in buds of dormant and sprouting potato tubers 总被引:2,自引:0,他引:2
M. Z. Dogonadze N. P. Korableva T. A. Platonova G. L. Shaposhnikov 《Applied Biochemistry and Microbiology》2000,36(5):507-509
Gibberellic and β-indolylacetic acids at concentrations of 10−7-10−5 M were shown to change the hormonal status and duration of true dormancy in potato tubers. Gibberellic acid shortened the
true dormancy and decreased the contents of abscisic acid and ethylene in the apical meristem. β-Indolylacetic acid elongated
the true dormancy and decreased abscisic acid production, but caused a more than tenfold increase in the production of ethylene
by apical tissues. The data suggest that β-indolylacetic acid and ethylene, as well as gibberellic and abscisic acids, are
involved in the regulation of true dormancy in potato tubers. 相似文献
4.
Scales of lily bulbs are swollen petioles. Lily scale fragments cultured in vitro regenerate bulblets consisting of scales that may or may not carry a leaf blade. The bulblets are dormant and require a cold
treatment to sprout. We added the gaseous plant growth regulator methyl jasmonic acid (MeJA) in the headspace of the tissue-culture
container and studied the effect on plantlet morphology (scale/leaf-blade formation) and dormancy development in three lilies,
Lilium speciosum “Rubrum No. 10,” L. longiflorum “Snow Queen,” and the Asiatic hybrid “Connecticut King.” Methyl jasmonic acid strongly reduced leaf-blade formation in Lilium longiflorum and Connecticut King. This was a specific effect as scale formation was affected much less. The specific inhibition of leaf-blade
formation was not observed in Lilium speciosum. In this lily, high concentrations of methyl jasmonic acid (MeJA) inhibited leaf-blade and scale formation to similar extents.
Methyl jasmonic acid reduced dormancy development in all three lilies, with the largest effect observed in Connecticut King.
In this Asiatic hybrid, almost all bulblets that had regenerated at 300 or 1000 μl l−1 MeJA in the headspace, did not require a dormancy-breaking treatment to achieve sprouting after planting in soil. Previously,
it has been found in lily that treatments that reduce leaf-blade formation promote dormancy development. The present findings
with MeJA do not agree with this. In the three lilies, the various parameters that were studied—regeneration, scale weight,
leaf-blade weight, and dormancy development—were very differently affected by MeJA. 相似文献
5.
The effect of smoke and smoke-derived butenolide in releasing dormancy of caryopses (referred to as seeds) of the economically
important weed Avena fatua L. was studied. Seeds of A. fatua are dormant after harvest. Both smoke-water and butenolide, applied continuously, removed dormancy in darkness at 15, 20
and 25°C and slightly at 30°C. Butenolide was very active at a concentration of 10−8 M. Butenolide at 10−8 M was also able to remove dormancy at 20°C when applied for 12 or 24 h at 4°C or for 3 to 24 h at 20°C. Sensitivity to butenolide
decreased with longer preincubation times in water. This compound was less effective in releasing dormancy in the light than
in darkness. Dormancy release by butenolide involves induction of cell-cycle activity just before coleorhiza protrusion. Stimulatory
effects of smoke-water and butenolide were also observed in respect of seedling growth and vigor. 相似文献
6.
Hidenobu Kunii 《Journal of plant research》1982,95(2):109-124
The life cycle and growth ofPotamogeton crispus L. were studied in a shallow pond, Ojaga-ike. With respect to the shoot elongation and seed and turion formations, the life
cycle of this plant in the pond could be divided into following five stages: germination, inactive growth, active growth,
reproductive and dormant stages. It was suggested that the plant showed these successive stages depending mainly upon water
temperature. The turions germinated on the bottom in autumn when the water temperature fell below ca. 20 C. The plant showed
hardly any growth during winter (December—early March) when the temperature was below 10 C. In the spring when the bottom
water temperature rose to above 10 C (mid-March), the plant started to grow again and the shoot elongated rapidly at the rate
of 4.2 cm day−1 until the shoot apex reached the pond surface in late April. Both the increment of node number and the internodal elongation
were associated with this rapid shoot growth. On 10 May (last sampling date), the mean values of shoot length, internodal
length and the number of nodes estimated for 10 predominant plants were 238.2±5.6 cm, 7.1±0.8 cm and 34.9±4.0 cm, respectively.
The turion formation and flowering occurred during the period from mid-April to mid-May when the surface water temperature
ranged 19 and 22 C. The dry weight of a plant reached the maximum mean value of 1180 mg on 10 May. At its peak biomass, an
individual plant produced 1–10 turions (5.5 on average) of which the mean individual turion dry weight was 53.2 mg. The turion
dry weight accounted for ca. 42% of the total plant biomass m−2 at that time. 相似文献
7.
Effects of Cadmium on Root Growth, Cell Division and Nucleoli in Root Tip Cells of Garlic 总被引:3,自引:0,他引:3
The effects of different concentrations (10−7 to 10−2 M) of cadmium chloride on root growth, cell division and nucleoli in root tip cells of Allium sativum L. were investigated. At lower concentrations of Cd2+ (10−7 to 10−6 M), Cd2+ did not influence the root growth, even had a stimulation effects during a short treatment. The results showed that the rate
of root growth per day at the treatment groups (10−4 to 10−2 M Cd2+) decreased with increasing duration of the treatment and increasing Cd2+ concentration. Cd2+ induced c-mitosis, anaphase bridges, chromosome stickiness and on nucleoli, causing some particles of similar silver-stained
material scattered in the nuclei and making the silver staining reaction at the periphery of the nucleolus weaker.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
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
9.
Nitric oxide,hydrogen cyanide and ethylene are required in the control of germination and undisturbed development of young apple seedlings 总被引:1,自引:0,他引:1
Agnieszka Gniazdowska Urszula Krasuska Karolina Czajkowska Renata Bogatek 《Plant Growth Regulation》2010,61(1):75-84
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are emerging as important regulators of plant development
(germination, flowering, senescence), acting as secondary messengers in cooperation with classical phytohormones. Apple seeds
are dormant, unless they undergo a 3 month long cold stratification. Deep dormancy of isolated apple embryos can also be broken
by short pre-treatment with HCN or NO with the effect associated with enhanced ethylene synthesis. Non-dormant embryos germinate
well and young seedlings grown from non-dormant embryos do not exhibit any morphological anomalies, such as asymmetric growth
and greening of cotyledons. One of the aims of this work was to investigate the correlation between RNS- mediated (HCN- and
NO-dependent) dormancy removal and ROS (H2O2 and O2−•) accumulation in the embryos. The beneficial effect of NO and HCN on germination of dormant apple embryos has been associated
with marked increases in H2O2 and O2−• concentration in the embryos at early germination stages. We also analyzed growth of young seedlings developed from embryos
pre-treatment with HCN or NO or exposed to ethylene (ethephone) and its precursor 1-aminocyclopropane-1-carboxylic acid (ACC).
ACC and ethephone removed all morphological anomalies of the seedlings (asymmetric growth and greening of cotyledons) but
the radicle growth was rather slight. We propose that accumulation of ROS provoked by HCN and NO pre-treatment is required
for embryo germination “sensu stricto”, while ethylene is required for post-germination seedling growth. 相似文献
10.
Jasmonic acid affects changes in the growth and some components content in alga Chlorella vulgaris 总被引:1,自引:0,他引:1
Romuald Czerpak Alicja Piotrowska Katarzyna Szulecka 《Acta Physiologiae Plantarum》2006,28(3):195-203
The present study was undertaken to test the influence of exogenous applied jasmonic acid upon the growth and changes in some
metabolites levels in the cells of green alga Chlorella vulgaris Beijerinck (Chlorophyceae). It was found, that JA in algal cells acted in a concentration-dependent manner. Treatment with
JA at high concentrations range of 10−5–10−4 M, resulted in the decrease in cell number and reduction of major photosynthetic pigments, monosaccharides, soluble cellular
and extracellular proteins levels as well as decrease in pH of the medium. In contrast to 10−5 and 10−4 M JA, this phytohormone applied at 10−8–10−6 M induced the increase in cell number, photosynthetic pigments and monosaccharides contents, significant accumulation and
extracellular secretion of soluble proteins over control and neutralization of the medium. Quantitative changes in polypeptide
pattern of total cellular proteins after treatment with the optimal concentration of 10−7 M JA on the 7th day of cultivation as analyzed by SDS-PAGE, was also observed. JA induced synthesis de novo of 15 specific polypeptides with molecular weight 334-16 kDa which were’t detected in the control. The data suggest that
JA plays a important role in algal growth and development. 相似文献
11.
Romuald Czerpak Andrzej Bajguz Marta Gromek Grażyna Kozłowska Izabela Nowak 《Acta Physiologiae Plantarum》2002,24(1):45-52
This study was conducted to investigate the influence of salicylic acid (SA) on the growth and changes of nucleic acids, protein,
photosynthetic pigments, sugar content and photosynthesis levels in the green alga Chlorella vulgaris Beijerinck (Chlorophyceae). The most significant changes in the content of nucleic acids and proteins was observed at the concentration 10−4 M SA between 8 and 12 day of cultivation. This concentration of SA increased the number of cells (about 40 %) and content
of proteins (about 60 %) and its secretion to the medium. The slight stimulation of protein secretion occurred on the 12th
day of cultivation at concentration 10−4 M, while in the range of 10−5 M to 10−6 M the protein secretion was inhibited. SA also stimulated the content of nucleic acids, especially RNA by 20–60 %, compared
with the control. The most stimulating influence upon the contents of chlorophylls a and b (50–70 %), total carotenoids (25–57 %), sugar (27–41 %) and intensity of net photosynthesis (18–33 %) was found at 10−4 M of SA. At the concentration of 10−6 M SA the slight inhibition of growth and biochemical activity of the algae was recorded at the first days of cultivation. 相似文献
12.
Upon treatment with 10−4 M IAA the membrane potential of an isolated cell from the main pulvinus, ofMimosa pudica L. depolarized by about 6 mV in 2–5 min, but later it gradually hyperpolarized by about 30 mV. The membrane potential of
a motor cell in the main pulvinar tissue hyperpolarized by about 80 mV 1 hr after application of 10−4 M IAA. 相似文献
13.
Z. J. Zhang W. J. Zhou H. Z. Li G. Q. Zhang K. Subrahmaniyan J. Q. Yu 《Biologia Plantarum》2006,50(3):453-456
The shoot fresh mass, root length and root numbers of two potato (Solanum tuberosum L.) cultivars Favorita and Helanwuhua were increased significantly by the application of 0.2 – 2 mg dm−3 jasmonic acid (JA) in the Murashige and Skoog medium. However, the growth of potato explants was inhibited by JA at high
concentrations (20 – 50 mg dm−3). Chlorophyll content in explant leaves decreased with an increase in the concentration of JA. In leaves treated with 0.2
mg dm−3 JA acid peroxidase activity increased, while in the leaves treated with more than 2 mg dm−3 JA peroxidase activity decreased. Under the dark, the microtuber numbers, fresh mass and percentage of big microtubers of
two potato cultivars were not promoted by the application of 0.2 – 50 mg dm−3 JA. 相似文献
14.
Dormancy in the hard seed coats of Mediterranean species is considered a strategy that enables persistent seed banks to be
formed in the soil. An important factor related to seed coat fracture and dormancy breakage in Mediterranean ecosystems is
heat. Nevertheless, the effect of factors other than heat on dormancy breakage in these species has hardly been studied. To
investigate the different ecological factors involved in germination, in the laboratory we applied several scarification treatments
to seeds with chromatic polymorphism. We evaluated the effect of soil seed depth during experimental burns by sowing seeds
at −1, −3 and −5 cm in the soil profile, and we also studied the effect of seed origin on the posterior germination of seeds
from 4 and 10 year-old shrubs as well as from the soil seed bank. U. parviflorus shows clear chromatic polymorphism: its brown seeds present higher dormancy levels than its yellow seeds. The different techniques
of dormancy breakage result in different degrees of germination; the highest degree of germination is generated by the mechanical
treatment, followed by the acid and the heat treatments, in that order. The depth of the seeds in the soil determines the
temperature thresholds and the residence times of these temperatures and whether they stimulate a massive germination at the
−1 cm soil profile or only a slight germination at the −5 cm depth. Seeds recently produced by the plant show higher dormancy
levels than seeds extracted from soil seed banks. Dormancy levels also depend on the shrubland age used for extracting the
soil samples (3>9 years old). In effect, from the point of view of dormancy, the germination behaviour of U. parviflorus seeds seems to follow a multiresponse strategy based on different seed populations and involving both biological and abiotic
processes to break dormancy. 相似文献
15.
Standardized laboratory techniques for the vegetative growth of the duckweedSpirodela polyrhiza (Lemnaceaé), and for formation as well as germination of their turions were described. Increasing photon fluence rates of blue or red
light increased the yield of turions. A specific stimulating effect of blue light was demonstrated under autotrophic but not
under mixotrophic conditions. Therefore the spectral composition of light is not important in mixotrophic formation of turions
whereas in autotrophic formation light sources with a higher portion of blue light are recommended. Dark-grown (etiolated)
turions showed accelerated germination and higher germination percentage in comparison with light-grown turions after induction
by a single red light pulse. This difference was overcome in continuous red light by speeding up the germination response
of light-grown turions. Use of Petri dishes (8 cm3 nutrient solution) instead of Erlenmeyer flasks (50 cm3 nutrient solution) retarded germination response. Especially for long term experiments the use of Erlenmeyer flasks is recommended.
Storage of turions for 72 h at 25 ‡C following at 5 ‡C in darkness after-ripening resulted in a decreased lag phase of the
light-induced germination both after induction by a single light pulse and in continuous light.
We thank Dr. Halina Gabrys, University of Crakow, Poland for critical discussion. 相似文献
16.
Effect of auxin on mesocotyl elongation of dark-grown maize under different seeding depths 总被引:1,自引:0,他引:1
In order to elucidate the physiological mechanism of maize mesocotyl elongation induced by auxin under different seeding depths,
seeds of five maize inbred lines, including 3681-4 line tolerant to deep seeding, were treated with IAA and triiodobenzoic
acid (TIBA) under seeding depths of 20 or 2 cm. Under deep seeding conditions, maize mesocotyls grew by 1.5–2.0 times faster
than under shallow seeding conditions. IAA (10−6 to 10−4 M) applied to roots stimulated mesocotyl elongation only of 3681-4 line and only under deep seeding conditions. TIBA (10−5 and 10−4 M) applied to roots inhibited mesocotyl elongation in all lines, but only 3681-4 was sensitive to 10−6 M TIBA. IAA promoted only cell elongation, and TIBA inhibited both cell elongation and cell division. After IAA and TIBA
treatments, endogenous IAA content changed in parallel with the mesocotyl growth rate under different seeding depths. Furthermore,
ABP1 gene expression changed in parallel with the mesocotyl growth rate under deep seeding conditions. Therefore, deep seeding
tolerance of 3681-4 line was achieved due to auxin-regulated rapid mesocotyl elongation. 相似文献
17.
The thickening that appeared on maize roots under the influence of 6-benzylaminopurine and α-naphthylacetic acid (concentration
10−5, 10−6, 10−7 and 10−8 M) were analysed. The changes in length and width of maize roots at the edge of elongation zone after 24,48 and 72 h of treatment
were studied. The growth in length of cells at the edge of elongation zone stopped abruptly but the growth in width slowly
continued. So, the growth of cells in length and width under the influence of growth regulators was not simultaneous. They
had distinct time limits. 相似文献
18.
Studies were conducted to characterize the effect of gene amplification and foreign gene expression on recombinant CHO cell
growth. Chinese hamster ovary (CHO) cells were transfected with an expression vector containing the gene for dihydrofolate
reductase (dhfr) and the gene for human β-interferon (β-IFN) or thelac Z gene which codes for β-galactosidase (β-gal). The recombinant genes in these CHO cells were amplified stepwise by growth
in 0, 10−7, and 10−6 M methotrexate (MTX), and the β-gal expressing cells were adapted to suspension culture. Flow cytometric methods (FCM) were
used to measure the distribution of amplifieddhfr gene content and foreign β-gal gene expression in the cell populations. A biochemical assay for β-gal was also used. Beta-gal
expression was found to increase with increasing gene amplification. The growth rate of recombinant CHO cells at 10−7 M MTX was found to be 20% lower than that of recombinant CHO cells in MTX-free medium, and the cell growth rate at 10−6 M MTX was 20% lower than that of recombinant CHO cells at 10−7 M MTX. There was no effect of 10−5 M MTX on the growth of CHO-DG44 (dhfr-) cells. The reduction of growth rate in recombinant CHO cells is therefore thought to be mainly due to the effect ofdhfr and foreign gene amplification and increased β-galactosidase expression. 相似文献
19.
Wen-Hao Chen Chun-Ming Xu Jian-Li Zeng Bing Zhao Xiao-Dong Wang Yu-Chun Wang 《World journal of microbiology & biotechnology》2007,23(10):1451-1458
At appropriate concentrations, polyamines promoted the callus growth and echinacoside content of Cistanche deserticola while Ag+ increased the content of echinacoside and acteoside. In a 20-day culture period, when putrescine (25 μM) and Ag+ (10 μM) were added on day 8 and day 16, respectively, the echinacoside production (1.7 g l−1) and acteoside production (0.4 g l−1) reached the maximum, which were 1.4-fold and 1.5-fold of those in single putrescine treatment, 1.6-fold and 1.4-fold of
those in single Ag+ treatment, respectively. Exogenous putrescine enhanced cell viability and antioxidant enzyme activity markedly, so increased
the final biomass. Ag+ addition increased H2O2 content and phenylalanine ammonia-lyase activity significantly which led to higher echinacoside and acteoside contents. 相似文献
20.
Tamara I. Balakhnina Anatoly B. Gavrilov Teresa M. Włodarczyk Aneta Borkowska Magdalena Nosalewicz Irina R. Fomina 《Plant Growth Regulation》2009,57(2):127-135
Barley (Hordeum vulgare L.) seeds were soaked in aqueous 10−4 M dihydroquercetin (DHQ) to examine its influence on seed germination and further growth of seedlings under optimal soil
watering and flooding conditions. The adaptive potential of the plants was estimated by the content of thiobarbituric acid
reactive substances (TBARs) and the activity of ascorbate peroxidase (AsP). High-grade seeds were germinated evenly under
(−DHQ)- and (+DHQ)-treatments. Low-grade seeds soaked in DHQ, showed no mold and twofold germination rate in comparison with
the same seeds soaked in water. The seedlings grown from the similarly germinated seeds did not differ from each other in
the shoot growth, independent of the DHQ-pretreatment. The root growth was higher in DHQ-pretreated plants. Soil flooding
suppressed the shoot and root growth rates in non-pretreated and DHQ-pretreated plants, however TBARs content was lower in
the roots and leaves of (+DHQ)-seedlings as compared to the (−DHQ)-ones. The activity of AsP increased more significantly
in the (+DHQ)-plants. The ratio between TBARs content and the AsP activity was lower in the leaves of (+DHQ)-plants both under
optimal soil conditions and flooding. Thus, the treatment of low-grade barley seeds with DHQ protects the seeds against mold
and increases adaptive potential of the seedlings. 相似文献