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1.
A. K. Glyan’ko N. B. Mitanova A. V. Stepanov 《Applied Biochemistry and Microbiology》2012,48(1):83-89
The article studies the nitric oxide (NO) levels in the roots of etiolated seedlings of sowing peas (Pisum sativum L.) using the DAF-2DA fluorescent probe and fluorescent microscopy. Cross sections of roots of 100–150 μm (the site of a
root which is 10–15 mm from the apex) are analyzed. It is shown that the level of NO in the roots after 24 h increased by
more than a factor of 2 in the versions with NaNO2 and sodium nitroprusside. At feeding the seedlings with KNO3, a peak in the accumulation of NO in the roots (twofold increase) was observed after 30 min. Fertilizing seedlings with L-arginine
(2 mM) increased the intensity of the fluorescence of the root sections by more than a factor of 2. The inoculation of seedlings
of rhizobia (Rhizobium leguminosarum bv. viceae) contributed to the reduction of NO on the background of the control (H2O) and sodium nitroprusside and nitrogen compounds.
Scavengers of NO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), hemoglobin) and inhibitors of nitrate reductase and animal NO synthase (sodium tungstate and aminoguanidine hydrochloride)
reduced the level of NO in the roots. The results are discussed in relation to the role of NO in plants under the influence
of biotic and abiotic factors. 相似文献
2.
Physiological adaptations to phosphorus deficiency during proteoid root development in white lupin 总被引:33,自引:0,他引:33
Release of large amounts of citric acid from specialized root clusters (proteoid roots) of phosphorus (P)-deficient white
lupin (Lupinus albus L.) is an efficient strategy for chemical mobilization of sparingly available P sources in the rhizosphere. The present study
demonstrates that increased accumulation and exudation of citric acid and a concomitant release of protons were predominantly
restricted to mature root clusters in the later stages of P deficiency. Inhibition of citrate exudation by exogenous application
of anion-channel blockers such as ethacrynic- and anthracene-9-carboxylic acids may indicate involvement of an anion channel.
Phosphorus-deficiency-induced accumulation and subsequent exudation of citric acid seem to be a consequence of both increased
biosynthesis and reduced metabolization of citric acid in the proteoid root tissue, indicated by increased in-vitro activity and enzyme protein levels of phosphoenolpyruvate carboxylase (EC 4.1.1.31), and reduced activity of aconitase (EC
4.2.1.3) and root respiration. Similar to citric acid, acid phosphatase, which is secreted by roots and involved in the mobilization
of the organic soil P fraction, was released predominantly from proteoid roots of P-deficient plants. Also 33Pi uptake per unit root fresh-weight was increased by approximately 50% in juvenile and mature proteoid root clusters compared
to apical segments of non-proteoid roots. Kinetic studies revealed a K
m of 30.7 μM for Pi uptake of non-proteoid root apices in P-sufficient plants, versus K
m values of 8.5–8.6 μM for non-proteoid and juvenile proteoid roots under P-deficient conditions, suggesting the induction
of a high-affinity Pi-uptake system. Obviously, P-deficiency-induced adaptations of white lupin, involved in P acquisition
and mobilization of sparingly available P sources, are predominantly confined to proteoid roots, and moreover to distinct
stages during proteoid root development.
Received: 10 September 1998 / Accepted: 22 December 1998 相似文献
3.
Summary This study examined the effects of aggregate size on root impedance and developed an equation to describe the root pressure
necessary to avoid deflection around an aggregate. This critical root pressure was predicted to increase with increasing aggregate
size, decreasing root diameter, and decreasing deflection angle. In growth chamber experiments, maize (Zea mays L.) seedlings were grown in A horizon material of Groseclose silt loam (Clayey, mixed, mesic, Typic Hapludult). The soil
had been moist sieved into different aggregate sizes (0–1, 1–2, 2–3, and 3–6 mm diameter). The larger aggregates did constitute
a slight root impedance as roots were deflected around them. Diameters of roots grown in 3–6 mm aggregates increased significantly,
whereas root lengths were not always signficantly decreased. The smaller aggregates did not impede root growth and were readily
displaced by roots. Large aggregates were more of an impedance to lateral roots than to main axes. 相似文献
4.
The redistribution of soil water by tree root systems 总被引:29,自引:0,他引:29
Plant roots transfer water between soil layers of different water potential thereby significantly affecting the distribution
and availability of water in the soil profile. We used a modification of the heat pulse method to measure sap flow in roots
of Grevillea robusta and Eucalyptus camaldulensis and demonstrated a redistribution of soil water from deeper in the profile to dry surface horizons by the root system. This
phenomenon, termed “hydraulic lift” has been reported previously. However, we also demonstrated that after the surface soils
were rewetted at the break of season, water was transported by roots from the surface to deeper soil horizons – the reverse
of the “hydraulic lift” behaviour described for other woody species. We suggest that “hydraulic redistribution” of water in
tree roots is significant in maintaining root viability, facilitating root growth in dry soils and modifying resource availability.
Received: 26 January 1998 / Accepted: 15 April 1998 相似文献
5.
Alan B. Darlington Anna Halinska James F. Dat T. J. Blake 《Trees - Structure and Function》1997,11(4):223-228
Plant responses to saturation vapour pressure deficit (SVPD) were studied by subjecting black spruce [Picea mariana (Mill) B.S.P.] and jack pine seedlings (Pinus banksiana Lamb.) to humid (0.3 – 0.8 kPa) or dry (2.0 – 2.5 kPa SVPD) regimes for 4 weeks using a computer-controlled environmental
system to control diurnal variation in SVPD. Dry matter accumulation in needles was not altered by increasing SVPD. However,
root growth declined by 60% which increased shoot to root ratio and reduced total seedling dry weight in both black spruce
and jack pine. Relative growth rate of jack pine also declined to about half the rate of plants grown under humid conditions.
In situ root marking studies showed that the decline in root growth of jack pine under the high SVPD was the result of reduced
lateral root initiation, whereas root elongation was unaffected by humidity. A 4-week exposure to dry air increased abscisic
acid (ABA) levels in needles, but not roots, of jack pine whereas ABA levels in black spruce were not altered. A short (3-day)
exposure failed to increase needle ABA levels in either species. These results suggest that the responses of conifers to dry
air were not the result of ABA accumulation.
Received: 24 March 1996 / Accepted: 30 May 1996 相似文献
6.
Organospecific responses of lupin seedlings to lead I. localization of lead ions and stress proteins
Roman Przymusiński Agnieszka Banaszak Edward A. Gwóźdź 《Acta Physiologiae Plantarum》2001,23(1):109-116
A tissue-printing technique was used to follow distribution of lead ions in different organs of lupin seedling with the histological
localization of pathogenesis-related proteins designated as PR-L1 to PR-L6, which were found to be induced in lupin roots
by heavy metals (Przymusiński and Gwóźdź 1999). Lead nitrate solution was supplied to the root tips and the histological distribution
of the metal in lupin organs was visualized by staining with 0.6 % (w/v) of sodium rhodizonate. As the distance from the site
of lead application increased, the amount of free lead ions decreased and in the petioles the metal was not detected at all.
Lead ions were localized mostly in vascular bundles, which suggests that it was transported into the upper parts of seedlings
with the transpiration stream.
Immunohistochemical analysis of the tissue prints showed that as compared to the control lead visibly increased the accumulation
of the PR proteins in roots, hypocotyls, stems and leaf petioles of the lupin seedling.
The histological distribution of the PR protein differs from that of lead, and was localized in parenchymatic cells of root
cortex, hypocotyl and stem. It is worth noticing that the stress protein was also observed in the leaf petioles where lead
was not detected. This fact as well as marked enhancement of PR (L1–L6) proteins accumulation in lead treated seedlings and
our earlier studies (Przymusiński and Gwóźdź 1994, 1999, Przymusiński et al. 1995) suggests that these proteins could be elements of plant’s defence system against both biotic and abiotic stressing
factors. 相似文献
7.
In vitro breeding and somaclonal variation were used as tools to improve the potential of Indian mustard (Brassica juncea L.) to extract and accumulate toxic metals. Calli from B. juncea were cultivated on a modified MS medium supplemented with 10–200 μM Cd or Pb. Afterwards, new B. juncea somaclones were regenerated from metal-tolerant callus cells. Three different phenotypes with improved tolerance of Cd, Zn
and Pb were observed under hydroponic conditions: enhanced metal accumulation in both shoots and roots; limited metal translocation
from roots to shoots; reduced accumulation in shoots and roots. Seven out of thirty individual variants showed a significantly
higher metal extraction than the control plants. The improvement of metal shoot accumulation of the best regenerant (3× Cd,
1.6× Zn, 1.8× Pb) and metal extraction (6.2× Cd, 3.2× Zn, 3.8× Pb) indicated a successful breeding and selection of B. juncea, which could be used for phytoremediation purpose. 相似文献
8.
Abscisic acid and hydraulic conductivity of maize roots: a study using cell- and root-pressure probes 总被引:31,自引:0,他引:31
Using root- and cell-pressure probes, the effects of the stress hormone abscisic acid (ABA) on the water-transport properties
of maize roots (Zea mays L.) were examined in order to work out dose and time responses for root hydraulic conductivity. Abscisic acid applied at
concentrations of 100–1,000 nM increased the hydraulic conductivity of excised maize roots both at the organ (root Lpr: factor of 3–4) and the root cell level (cell Lp: factor of 7–27). Effects on the root cortical cells were more pronounced
than at the organ level. From the results it was concluded that ABA acts at the plasmalemma, presumably by an interaction
with water channels. Abscisic acid therefore facilitated the cell-to-cell component of transport of water across the root
cylinder. Effects on cell Lp were transient and highly specific for the undissociated (+)-cis-trans-ABA. The stress hormone ABA facilitates water uptake into roots as soils start drying, especially under non-transpiring conditions,
when the apoplastic path of water transport is largely excluded.
Received: 26 February 2000 / Accepted: 17 August 2000 相似文献
9.
An image analysis method for determination of spatial colonization patterns of bacteria in plant rhizosphere 总被引:4,自引:0,他引:4
D. P. Roberts D. Y. Kobayashi P. D. Dery N. M. Short Jr 《Applied microbiology and biotechnology》1999,51(5):653-658
A method that allows the rapid visualization of bacterial spatial colonization patterns on roots for the determination of
general colonization trends was developed. This method, which analyzes images of roots, and bioluminescence-enhanced images
of bacterial colonization patterns on these roots, was used to study the colonization patterns of seed-applied Enterobacter cloacae strain E6 on 3-day-old cucumber plants. Conventional dilution-plating methods indicated that E6 colonized cucumber tap roots
in high populations and that these populations significantly decreased as the distance from the seed increased. In addition
to confirming these observations, image analysis indicated that colonization by E6 significantly decreased on lateral roots
as the distance increased horizontally away from the tap root, and that this bacterium did not evenly cover the most densely
colonized regions of the cucumber root system. Results from these experiments indicate that the majority of E6 populations
on cucumber roots after seed application are limited to the upper regions of the tap root and that E6 does not effectively
colonize other regions of the root system.
Received: 15 June 1988 / Received revision: 19 November 1998 / Accepted: 29 November 1998 相似文献
10.
Silicate-Mediated Alleviation of Pb Toxicity in Banana Grown in Pb-Contaminated Soil 总被引:4,自引:0,他引:4
Silicate (Si) can enhance plant resistance or tolerance to the toxicity of heavy metals. However, it remains unclear whether
Si can ameliorate lead (Pb) toxicity in banana (Musa xparadisiaca) roots. In this study, treatment with 800 mg kg−1 Pb decreased both the shoot and root weight of banana seedlings. The amendment of 800 mg kg−1 Si (sodium metasilicate, Na2SiO3·9H2O) to the Pb-contaminated soil enhanced banana biomass at two growth stages significantly. The amendment of 800 mg kg−1 Si significantly increased soil pH and decreased exchangeable Pb, thus reducing soil Pb availability, while Si addition of
100 mg kg−1 did not influence soil pH. Results from Pb fractionation analysis indicated that more Pb were in the form of carbonate and
residual-bound fractions in the Si-amended Pb-contaminated soils. The ratio of Pb-bound carbonate to the total Pb tended to
increase with increasing growth stages. Treatment with 100 mg kg−1 Si had smaller effects on Pb forms in the Si-amended soils than that of 800 mg kg−1 Si. Pb treatment decreased the xylem sap greatly, but the addition of Si at both levels increased xylem sap and reduced Pb
concentration in xylem sap significantly in the Si-amended Pb treatments. The addition of Si increased the activities of POD,
SOD, and CAT in banana roots by 14.2% to 72.1% in the Si-amended Pb treatments. The results suggested that Si-enhanced tolerance
to Pb toxicity in banana seedlings was associated with Pb immobilization in the soils, the decrease of Pb transport from roots
to shoots, and Si-mediated detoxification of Pb in the plants. 相似文献
11.
The responses of Ri-TDNA-transformed roots and arbuscular mycorrhizal fungi established on Ri-TDNA-transformed roots to lead-amended
media was investigated in vitro. At exposure to increasing concentrations of lead (2–10 mg/l[ppm]), three Ri-TDNA-transformed root clones viz., Swa, Swb and
Swc, exhibited profuse growth. At exposure to increasing concentrations of lead (0.1–5 ppm), the dual cultures of Ri-TDNA-transformed
roots and arbuscular mycorrhizal fungi., Glomus lamellosum/Swa, Glomus intraradices/Swb and Glomus proliferum/Swc, exhibited tolerance to 5 ppm of lead. When subjected to one physiological stress, either exposure to Pb or inoculation with AM fungi, Ri-TDNA-transformed root clones exuded more phenols in the growth medium
than retained in the roots. When subjected to dual physiological stress, mycorrhizal Ri-TDNA-transformed roots growing on Pb-enriched medium, the total phenol content increased in the roots and
exudation into the medium decreased. 相似文献
12.
Fei Chen Fang Wang Hongyan Sun Yue Cai Weihua Mao Guoping Zhang Eva Vincze Feibo Wu 《Journal of Plant Growth Regulation》2010,29(4):394-408
A greenhouse hydroponic experiment was performed using Cd-sensitive (cv. Dong 17) and Cd-tolerant (Weisuobuzhi) barley seedlings
to evaluate how different genotypes responded to cadmium (Cd) toxicity in the presence of sodium nitroprusside (SNP), a nitric
oxide (NO) donor. Results showed that 5 μM Cd increased the accumulation of O2•−, H2O2, and malondialdehyde (MDA) but reduced plant height, chlorophyll content, net photosynthetic rate (P
n), and biomass, with a much more severe response in the Cd-sensitive genotype. Antioxidant enzyme activities increased significantly
under Cd stress in the roots of the tolerant genotype, whereas in leaves of the sensitive genotype, superoxide dismutase (SOD)
and ascorbate peroxide (APX), especially cytosol ascorbate peroxidase (cAPX), decreased after 5–15 days Cd exposure. Moreover,
Cd induces NO synthesis by stimulating nitrate reductase and nitric oxide synthetase-like enzymes in roots/leaves. A Cd-induced
NO transient increase in roots of the Cd-tolerant genotype might partly contribute to its Cd tolerance. Exogenous NO dramatically
alleviated Cd toxicity, markedly diminished Cd-induced reactive oxygen species (ROS) and MDA accumulation, ameliorated Cd-induced
damage to leaf/root ultrastructure, and increased chlorophyll content and P
n. External NO counteracted the pattern of alterations in certain antioxidant enzymes induced by Cd; for example, it significantly
elevated the depressed SOD, APX, and catalase (CAT) activities in the Cd-sensitive genotype after 10- and 15-day treatments.
Furthermore, NO significantly increased stromal APX and Mn-SOD activities in both genotypes and upregulated Cd-induced decrease
in cAPX activity and gene expression of root/leaf cAPX and leaf CAT1 in the Cd-sensitive genotype. These data suggest that under Cd stress, NO, as a potent antioxidant, protects barley seedlings
against oxidative damage by directly and indirectly scavenging ROS and helps to maintain stability and integrity of the subcellular
structure. 相似文献
13.
Uwe Nehls Thierry Béguiristain Frank Ditengou Frédéric Lapeyrie Francis Martin 《Planta》1998,207(2):296-302
14.
Sylwia Pawlak Anna Firych Katarzyna Rymer Joanna Deckert 《Acta Physiologiae Plantarum》2009,31(4):741-747
The cadmium (Cd2+) and lead (Pb2+)-induced changes in Cu,Zn-SOD gene expression on the level of mRNA accumulation and enzyme activity were analyzed in roots of soybean (Glycine
max) seedlings. The Cd2+ caused the induction of copper–zinc superoxide dismutase (Cu,Zn-SOD) mRNA accumulation, at each analyzed metal concentration
(5–25 mg/l), whereas in Pb2+-treated roots this effect was observed only at the medium metal concentrations (50–100 mg/l of Pb2+). The analysis of Cu,Zn-SOD activity proved an increase in enzyme activity during Cd2+/Pb2+ stresses, however in Pb2+-treated plants the activity of enzyme was not correlated with respective mRNAs level. Presented data suggest that different
metals may act on various level of Cu,Zn-SOD expression in plants exposed to heavy metals stress. 相似文献
15.
The accumulation of different precursors of carotenoid biosynthesis in carotenoid-deficient mutants of Chlamydomonas reinhardtii was studied by HPLC-analysis. ζ-Carotene accumulated in several ac5 mutants, this character cosegregated with mutations in the ac5 gene. Two groups of ac5 mutants differing in ζ-carotene accumulation were distinguished. One (ac5–1) accumulated ζ-carotene in the dark but not in the light. The other (ac5–2) accumulated ζ-carotene under both dark and light conditions. ac5–2 strains accumulated more ζ-carotene in the dark than ac5-1 strains. Genetic data suggested that the mutations ac5–1 and ac5–2 were allelic. Pleiotropic effects of mutations in the ac5 gene included decreased levels of chlorophyll a and b and acetate requirement. The results are consistent with the presence
of a defective ζ-carotene desaturase in ac5 mutants.
Received: 27 October 1998 / Revision received: 1 February 1999 / Accepted: 16 February 1999 相似文献
16.
Increased levels of rhizospheric dissolved inorganic carbon have repeatedly been demonstrated to enhance plant growth by up
to 80%, although carbon from dark fixation accounts for only 1–3% of total plant carbon gain. This study, therefore, aimed
at investigating the effects of bicarbonate on nitrate uptake, assimilation and translocation to shoots. Clonal saplings of
poplar (Populus canescens(Ait.) Sm.) and elder (Sambucus nigraL.) were grown hydroponically for 35 days in a nutrient solution containing 0, 0.5 and 1 mM bicarbonate and 2 mM nitrate as the sole nitrogen source at pH 7.0. Net nitrate uptake, root nitrate accumulation and reduction, and export of
nitrogenous solutes to shoots were measured after incubating plants with 15N-labelled nitrate for 24 h. Net nitrate uptake increased non-significantly in plant species (19–61% compared to control plants)
in response to 1 mM bicarbonate. Root nitrate reduction and nitrogen export to shoots increased by 80 and 95% and 15 and 44% in poplar and elder,
respectively. With enhanced root zone bicarbonate, both species also exhibited a marked shift between the main nitrate utilising
processes. Poplar plants increasingly utilised nitrate via nitrate reduction (73–88% of net nitrate uptake), whereas the proportions
of export (20–9%) and storage in roots (7–3%) declined as plants were exposed to 1 mM external bicarbonate. On the other hand, elder plants exhibited a significant increase of root nitrate reduction (44–66%)
and root nitrate accumulation (6–25%). Nitrate translocation to elder shoots decreased from 50 to 8% of net nitrate uptake.
The improved supply of nitrogen to shoots did not translate into a significant stimulation of growth, relative growth rates
increased by only 16% in poplar saplings and by 7% in elder plants.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
The influence of ammonium nitrate on the root growth and ericoid mycorrhizal colonization of Calluna vulgaris (L.) Hull from a Danish heathland 总被引:1,自引:0,他引:1
M. Johansson 《Oecologia》2000,123(3):418-424
Conversion of European heathlands to grassland has been reported as a response to increased nutrient availability, especially
of nitrogen; a direct effect upon mycorrhizal colonization has been proposed as an likely explanation.This hypothesis was
tested in a random block experiment with four blocks and four replicates on a Danish inland heath, Hjelm Hede. Ammonium nitrate
was applied (0, 35, 50 and 70 kg N ha–1 year–1) to a stand of Calluna vulgaris (L.) Hull four times annually for 2 years. Calluna roots were sampled on four occasions in the 2nd year of the nitrogen treatment. The extent of ericoid mycorrhizal colonization
was determined by direct observation of the roots using a line-intersection method. The nitrogen content of the current-year
shoots of Calluna increased when they were treated with nitrogen. Nitrogen fertilization had no significant effects on ericoid mycorrhizal
colonization of Calluna nor on root biomass. The seasonal variation in mycorrhizal colonization of the Calluna roots was highly significant. The spatial variability of mycorrhizal colonization, both in replicated plots and in the two
contrasted soil horizons – the mor layer and the bleached sand – within the plots, were considerable. I conclude that heather
decline under enhanced nitrogen input is unlikely to be caused by a direct impact on the ericoid mycorrhizae of Calluna.
Received: 1 December 1998 / Accepted: 7 December 1999 相似文献
18.
Pollution of agricultural land by heavy metals has imposed an increasingly serious risk to environmental and human health
in recent years. Heavy metal pollutants may enter the human food chain through agricultural products and groundwater from
the polluted soils. Progress has been made in the past decade on phytoremediation, a safe and inexpensive approach to remove
contaminants from soil and water using plants. However, in most cases, agricultural land in China cannot afford to grow phytoremediator
plants instead of growing crops due to food supply for the great population. Therefore, new and effective methods to decrease
the risk of heavy metal pollution in crops and to clean the contaminated soils are urgently needed. If we can find crop germplasms
(including species and varieties) that accumulate heavy metals in their edible parts, such as the leaves of vegetables or
grains of cereals, at a level low enough for safe consumption, then we can grow these selected species or varieties in the
lands contaminated or potentially contaminated by heavy metals. If we can find crop germplasms that take in low concentrations
of heavy metals in their edible parts and high content of the metals in their inedible parts, then we can use these selected
species or varieties for soil remediation. In this study, the feasibility of the method is assessed by analyzing Pb concentrations
in edible and inedible parts of 25 varieties of maize (Zea mays) grown in Pb-contaminated soils. The soil concentrations of Pb were 595.55 mg/kg in the high Pb exposed treatment and 195.55
mg/kg in the control.
The results showed that the Pb concentrations in different tissues were in the order of root > shoot ≅ leaf > grain. Compared
with the control, the Pb concentrations in root, shoot and leaf were greatly increased under the high Pb exposed condition,
while the increments of Pb concentration in grain were relatively lower. Under the high Pb exposure, the grain Pb concentrations
of 12 varieties exceeded the maximal Pb limitation of the National Food Hygiene Standard of China (NFHSC) and were inedible.
This indicates that there is a high Pb pollution risk for maize grown on Pb polluted sites. Although 22 of the 25 tested varieties
had harvest loss under the highly Pb stressed condition, ranging from 0.86%–38.7% of the grain biomass acquired at the control,
the average harvest loss of all the tested varieties was only 12.6%, which is usually imperceptible in normal farming practices.
Therefore the risk of Pb pollution in maize products cannot be promptly noticed and prevented based only on the outcome of
the harvest. However, we did find that 13 of the 25 tested varieties had grain Pb concentrations lower than the limitation
of the NFHSC. It is, therefore, possible to reduce the pollution risk if these favorable varieties are used for maize production
in Pb-contaminated or potentially contaminated agricultural lands.
Pb concentrations in vegetative tissues (root, stem and leaf) were significantly correlated with each other, while Pb concentrations
of each vegetative tissue were not significantly correlated with that of grain. Among the 25 tested varieties, some varieties
had Pb concentrations in grain lower than (No.1–3 and No.6) or slightly above (No.4) the limitation of the NFHSC, while their
Pb concentrations in the vegetative tissues were among the highest. When excluding these varieties, correlations between the
Pb concentrations of grain and those of vegetative tissues of the rest of the tested varieties became highly significant.
In addition, variety No. 1 had the lowest harvest loss under high Pb exposed, and the highest Pb accumulation in vegetative
tissues (51.69 mg/plant, 12 times as much as in the control). Similar features were also observed in varieties No.3, No.3
and No.6, which absorbed Pb for 36–42 mg/plant under high Pb exposed. We recommend these varieties of maize to be used for
bioremediation of Pb contaminated soil and crop production at the same time.
Translated from Acta Phytoecologica Sina, 2006, 29(6): 992–999 [译自: 植物生态学报] 相似文献
19.
20.
Using different explants of in vitro seed grown Scutellaria baicalensis Georgi plantlets, hairy roots were induced following inoculation of Agrobacterium rhizogenes strains A4GUS, R1000 LBA 9402 and ATCC11325. The A4GUS proved to be more competent than other strains and the highest transformation rates were observed in cotyledonary leaf
explant (42.6 %). The transformed roots appeared after 15–20 d of incubation on hormone free Murashige and Skoog medium. Growth
of hairy roots was assessed on the basis of total root elongation, lateral root density and biomass accumulation. Maximum
growth rate was recorded in root:medium ratio 1:100 (m/v). Hairy root lines were further established in Gamborg B5 medium and the biomass increase was maximum from 15 to 30 d. PCR, Southern hybridization and RT-PCR confirmed integration
and expression of left and right termini-linked Ri T-DNA fragment of the Ri plasmid from A4GUS into the genome of Scutellaria baicalensis hairy roots. GUS assay was also performed for further integration and expression. All the clones showed higher growth rate
them non-transformed root and accumulated considerable amounts of the root-specific flavonoids. Baicalin content was 14.1–30.0
% of dry root mass which was significantly higher then that of control field grown roots (18 %). The wogonin content varies
from 0.08 to 0.18 % among the hairy root clones which was also higher than in non-transformed roots (0.07 %). 相似文献