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1.
We have investigated the usefulness of hypocotyl (cultured on N1B2 medium) and cotyledon explants (on CR medium: Murashige
and Skoog (MS) medium, 3% sucrose, 20 μm benzylaminopurine, pH 5.8) for the regeneration of shoots of the Korean radish ‘Jin
Ju Dae Pyong’. The importance of ethylene (indirectly), polyamines and gelling agent were studied in both media. Although
the addition of ethylene-inhibitors and silver nitrate to the culture media were beneficial towards shoot regeneration and
agar-based treatments (0.8% w/v) being superior in shoot production compared to agarose treatments (0.4% w/v), both explants
responded differently in culture. Hypocotyls cultured in the presence of silver nitrate or aminoethoxyvinylglycine (AVG) regenerated
significantly (p < 0.05) more shoots compared to N1B2 medium alone; supplementation of 20 μM AVG to N1B2 medium gave optimal shoot production
(40% of explants regenerating shoots). The addition of 10 μM AVG to CR medium produced maximum shoot regeneration from cotyledon
explants (60% producing shoots). Plants derived from 3-month-old cultures produced greater seed weights, larger leaves and
greater genetic variability (50–80% of cells having 20–40 chromosomes) compared to seed-derived (85–90% diploid) and plants
from 1-month-old cultures (78–88% diploid). Our results show, that if prolonged culture of explants is avoided, a large number
of phenotypically-normal plants can be produced, which in turn, could be utilized in the genetic improvement of radish. 相似文献
2.
Caulogenic responses of various explant types from 12-month-old plants of Hemidesmus indicus were tested. Second and third visible nodes (0.5 cm) from the apex and root segments (0.5 cm) were the most and least regenerative
respectively, with the formation of 9.37 and 2.6 shoots in 4 weeks on half strength MS medium supplemented with 2.22 μM BA
and 1.07 μM NAA and 4.44 μM BA and 2.69 μM NAA respectively. Caulogenic ability of the nodes decreased with increasing maturity.
Shoot buds initiated upon the young nodes on day 10 developed into 7.2 cm long shoots within 4 weeks thereby making a shoot
elongation phase unnecessary. Nodal explants of the in vitro raised shoots subcultured in the same medium produced 9.32 shoots of 7.1 cm length in 3–4 weeks, similar to those of the
mature plant-derived nodes. Multiplication through subculture of the nodes up to 25 passages of 4 weeks each was achieved
without decline. Shoot cultures were rooted in quarter salt strength MS medium containing 9.8 μM IBA and the rooted plants
were hardened for establishment in pots at 96% rate. Four months after establishment, the micropropagated plants were stable
and showed uniform morphological and growth characteristic. After 12 months of cultivation in the field, on an average micropropagated
plant consisted of 4–5 shoots, 5–8 branches per shoot and increased root biomass (13.5 g) compared to the poor growth (single
shoot and 2–3 branches) and root production (4.6 g) values obtained with plants raised from conventional rooted stem cuttings.
The concentration of the root specific compound, 2-hydroxy 4-methoxy benzaldehyde per plant was 2–3 fold higher in micropropagated
plants though on unit dry root biomass (0.12% per g dry wt) basis it remained the same between two sources of plants.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
This report deals with micropropagation of the critically endangered and endemic Turkish shrub, Thermopsis turcica using callus, root and cotyledonary explants. Callus cultures were initiated from root and cotyledon explants on MS medium
supplemented with 0.5–20 μM NAA or 2,4-D. The root explants were found to be better in terms of quick responding and callusing
percentages as compared to the cotyledons. Organogenic callus production with adventitious roots and shoots were obtained
on MS medium with only NAA. The calli obtained with NAA, root and cotyledonary explants were cultured with BA and kinetin
(2–8 μM) alone or in combination with a low level (0.5 μM) of 2,4-D or NAA. The best regeneration of shoots from root explants
was observed on hormone-free MS medium. NAA with BA or kinetin in the medium improved shoot induction from the calli obtained
with NAA. Maximum percentage of shoots (93.3%), maximum number of shoots (6.2) and maximun length of shoots (8.22 cm) were
achieved from cotyledonary explants at 4 μM BA and 0.5 μM NAA. The presence of 0.5 μM or higher levels of 2,4-D in shoot induction
medium inhibited the regeneration in T. turcica explants. 83% of in vitro rooting was attained on pulsed-IBA treated shoots. The regenerated plants with well developed shoots and roots were successfully
acclimatized. Application of this study’s results has the potential to conserve T. turcica from extinction. 相似文献
4.
This greenhouse study aimed to determine the effect of colonization by the arbuscular mycorrhizal (AM) fungus (Glomus intraradices Schenck & Smith) on the “wild” tobacco (Nicotiana rustica L. var. Azteca), under soil–zinc (Zn) conditions. Plants of N. rustica were grown in AM or non-AM inoculated substrate and subjected to four soil–[Zn] concentrations (0, 50, 100, and 250 mg Zn kg−1 dry soil). The AM root colonization increased markedly from 14 to 81% with the increasing soil–[Zn] and the mycorrhizal structures were significantly more abundant at the highest soil–[Zn], suggesting that Zn may be involved directly or indirectly in AM root colonization. In addition, total Zn content or Zn concentrations in shoots and roots were shown to increase as soil–[Zn] increased in both AM and non-AM plants. As for the growth parameters studied, there were no significant differences between treatments despite the increase in Zn content or concentration. The AM roots subjected to the highest soil–[Zn] had a significant reduction by about 50% of total Zn content and Zn concentration compared to non-AM roots. Still, the relative extracted Zn percentage decreased dramatically as soil–[Zn] increased. Soil pH was significantly lower in non-AM than AM treatments at the highest soil–[Zn]. In summary, AM plants (particularly roots) showed lower Zn content and concentration than non-AM plants. In this regard, the AM fungi have a protective role for the host plant, thus playing an important role in soil-contaminant immobilization processes; and, therefore, are of value in phytoremediation, especially when heavy metals approach toxic levels in the soil. 相似文献
5.
Protoplasts from a total of thirty-six genotypes of Brassica species – B. napus, B. campestris (syn. B. rapa), B. juncea, and three distant relatives, Orychophragmus violaceus, Isatis indigotica and Xinjiang wild rape – were analysed for shoot regeneration using a feeder culture system. With the exception of B. campestris and Xinjiang wild rape, some genotypes of all the species could regenerate plants with high efficiency (above 20% of isolated
calli initiating shoots). Several genotypes with high regeneration ability were elite breeding lines. Culture conditions as
well as genotype had a significant impact on shoot regeneration frequency. In particular, silver nitrate added to the regeneration
medium at doses of 6 and 30 μM improved shoot regeneration frequency to 25.4% and 52.2% of isolated calli, respectively, compared
to 7.3% percent shoot regeneration without silver nitrate in seven responsive genotypes. Addition of silver nitrate to the
regeneration medium also induced shoot regeneration in non-responsive genotypes. Intact plants could be obtained within three
months from protoplast isolation in the regenerative genotypes using the current culture system. Advantages of mesophyll protoplasts
as compared to protoplasts isolated from hypocotyls for genetic manipulation in Brassica species are discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
Renata Matraszek 《Acta Physiologiae Plantarum》2008,30(3):361-370
The author studied the effect of different nickel concentrations (0, 0.4, 40 and 80 μM Ni) on the nitrate reductase (NR) activity
of New Zealand spinach (Tetragonia expansa Murr.) and lettuce (Lactuca sativa L. cv. Justyna) plants supplied with different nitrogen forms (NO3
−–N, NH4
+–N, NH4NO3). A low concentration of Ni (0.4 μM) did not cause statistically significant changes of the nitrate reductase activity in
lettuce plants supplied with nitrate nitrogen (NO3
−–N) or mixed (NH4NO3) nitrogen form, but in New Zealand spinach leaves the enzyme activity decreased and increased, respectively. The introduction
of 0.4 μM Ni in the medium containing ammonium ions as a sole source of nitrogen resulted in significantly increased NR activity
in lettuce roots, and did not cause statistically significant changes of the enzyme activity in New Zealand spinach plants.
At a high nickel level (Ni 40 or 80 μM), a significant decrease in the NR activity was observed in New Zealand spinach plants
treated with nitrate or mixed nitrogen form, but it was much more marked in leaves than in roots. An exception was lack of
significant changes of the enzyme activity in spinach leaves when plants were treated with 40 μM Ni and supplied with mixed
nitrogen form, which resulted in the stronger reduction of the enzyme activity in roots than in leaves. The statistically
significant drop in the NR activity was recorded in the aboveground parts of nickel-stressed lettuce plants supplied with
NO3
−–N or NH4NO3. At the same time, there were no statistically significant changes recorded in lettuce roots, except for the drop of the
enzyme activity in the roots of NO3
−-fed plants grown in the nutrient solution containing 80 μM Ni. An addition of high nickel doses to the nutrient solution
contained ammonium nitrogen (NH4
+–N) did not affect the NR activity in New Zealand spinach plants and caused a high increase of this enzyme in lettuce organs,
especially in roots. It should be stressed that, independently of nickel dose in New Zealand spinach plants supplied with
ammonium form, NR activity in roots was dramatically higher than that in leaves. Moreover, in New Zealand spinach plants treated
with NH4
+–N the enzyme activity in roots was even higher than in those supplied with NO3
−–N. 相似文献
7.
K. P. Singh R. K. Jaiswal Niranjan Kumar 《World journal of microbiology & biotechnology》2007,23(2):291-294
Summary
Catenaria anguillulae parasitized and killed the eggs and second stage juveniles (J2) of Meloidogyne graminicola under natural conditions. The percentage of infection in eggs was higher than J2 of M.␣graminicola, which ranged between 0–50.3% and 0–18.9% in 2004 and 0–46.6% and 0–21.7% in 2005, respectively. The higher parasitism of
eggs and J2 was recorded from those fields in which plants were severely infected with M. graminicola. The degree of parasitism of eggs and J2 by C. anguillulae varied with severity of root knot disease. The fields with a higher root gall index recorded a higher percentage of infection
in eggs and J2 of M. graminicola. In general, old galls when teased and incubated, recorded higher parasitism of eggs and juveniles than young galls. 相似文献
8.
D. Ste¸piński 《Biologia Plantarum》2003,47(3):333-339
Relative nuclear DNA contents in cortex parenchyma cells in root segments of 3- and 7-d-old soybean seedlings grown at 25
°C and in plants grown for 3 d at 25 °C, and then for 4 d at 10 °C, were determined with cytophotometry. Measurements revealed
that in each variant the cortex cell nuclei with DNA content between 2C and 8C were in all the examined segments and nuclei
with 8C – 16C DNA appeared in higher parts of roots. However, in chilled plant cells the number of 8C – 16C DNA nuclei was
very low. Therefore, chilling inhibited endoreplication in comparison with plants grown at 25 °C for 7 d, and even reduced
endopolyploidy level as compared to the initial seedlings, i.e. 3-d-old plants. DNA contents in root hairs grown at 25 °C (control) and in root hairs emerged at 10 °C were also determined.
In controls 4C – 8C DNA nuclei predominated while in chilled plants an additional population of 2C – 4C DNA appeared. Thus
a reduction of DNA synthesis was brought about by low temperature. The occurrence of an intermediate DNA contents besides
those with full endoreplication cycles suggests the possibility of differential DNA replication. This suggestion seems to
be supported by the lack of 3H-thymidine incorporation into root hair nuclei at the examined developmental stage both in control and chilled root hairs.
The same number, but larger, chromocentric lumps in polyploid cortex cell nuclei of higher root zones, in comparison to meristematic
nuclei, suggests that endoreduplication process occurred.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Tom Gichner Irena
nidar Jiina Szkov 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2008,652(2):186-190
Tobacco (Nicotiana tabacum L. var. xanthi) seedlings were treated with aqueous solutions of lead nitrate (Pb2+) at concentrations ranging from 0.4 mM to 2.4 mM for 24 h and from 25 μM to 200 μM for 7 days. The DNA damage measured by the comet assay was high in the root nuclei, but in the leaf nuclei a slight but significant increase in DNA damage could be demonstrated only after a 7-day treatment with 200 μM Pb2+. In tobacco plants growing for 6 weeks in soil polluted with Pb2+ severe toxic effects, expressed by the decrease in leaf area, and a slight but significant increase in DNA damage were observed. The tobacco plants with increased levels of DNA damage were severely injured and showed stunted growth, distorted leaves and brown root tips. The frequency of somatic mutations in tobacco plants growing in the Pb2+-polluted soil did not significantly increase. Analytical studies by inductively coupled plasma optical emission spectrometry demonstrate that after a 24-h treatment of tobacco with 2.4 mM Pb2+, the accumulation of the heavy metal is 40-fold higher in the roots than in the above-ground biomass. Low Pb2+ accumulation in the above-ground parts may explain the lower levels or the absence of Pb2+-induced DNA damage in leaves. 相似文献
10.
Summary Acclimation of wild radish plants to a simultaneous combination of SO2 fumigation and decreasing nitrate availability was investigated. Plants were grown for 24 d under continuous daytime (10h) exposure to 0 or 0.4 ppm SO2 and were grown in a nutrient solution with stable nitrate concentrations of 100 M for the first 15 d, 50 M from day 15 to day 19, and 25 M from day 19 to day 24. Analysis of relative growth rates (RGR) showed that radish plants responded rapidly to changes in nitrate availability and that SO2 treatment affected those responses. Shoot RGR of plants from both treatments and root RGR of control plants showed rapid declines and subsequent recoveries in response to decreasing nitrate availability. Root RGR of SO2-treated plants declined rapidly in response to decreased nitrate availability, but did not recover as quickly or completely as root RGR of control plants. Analysis of specific leaf weights and tissue nitrogen concentrations showed that control plants had significantly higher amounts of nitrogen in tissues after nitrate availability was lowered, and had higher rates of nitrate uptake in comparison to SO2-treated plants; especially when nitrate availability was highest. Furthermore, control plants had temporarily higher rates of root respiration in comparison to SO2-treated plants, suggesting that control plants temporarily allocated more resources to physiological processes occurring in roots, such as nutrient uptake. Although SO2-induced changes in growth and resource allocation of plants were relatively small, it was probable that SO2 treatment of radish plants affected plant nitrogen balance, and subsequently affected the ability of plants to respond to decreased nitrate availibility, by affecting resource partitioning to nitrate uptake and root growth. 相似文献
11.
12.
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
13.
Catapan Elizabete Otuki Michel Fleith Viana Ana Maria 《Plant Cell, Tissue and Organ Culture》2000,62(3):195-202
An efficient micropropagation protocol was developed for the medicinal plant Phyllanthus caroliniensis (Euphorbiaceae) using nodal segments for axillary shoot proliferation. Maximum multiplication (21–23 shoots per explant)
was achieved on MS or AR media supplemented with either 5.0 μM BA, 1.25–5.0 μM kinetin or 2.5–5.0 μM 2iP. Rooting was achieved
with 80–100% of the microshoots on MS medium without growth regulators, although 1.25 μM NAA and 1.25–5.0 μM IAA promoted
significant increases in the number of roots per explant. Regenerated plants were successfully acclimatized and about 88%
of plantlets survived under ex vitro conditions. Flowering was observed on in vitro grown plantlets and after 3–4 weeks of acclimatization. High frequency callus initiation and growth was achieved when nodal
segment explants were inoculated in the vertical position on MS medium supplemented with 5.0 μM 2,4-D. Root cultures were
successfully established on MS medium containing 1.1 μM NAA. The optimized micropropagation, callus and root culture protocols
offer the possibility to use cell/root culture techniques for vegetative propagation and secondary metabolism studies.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
Inger Martinussen G. Nilsen L. Svenson O. Junttila K. Rapp 《Plant Cell, Tissue and Organ Culture》2004,78(1):43-49
The purpose of this study was to establish conditions for micropropagation of cloudberry (Rubus chamaemorus L.). Cultures were initiated from meristem cultures. When cultures were subcultured from clusters of 3–5 shoots, approximately
70 and 50 shoots were produced per cluster within 6 weeks at 8.9 μM BAP for the female cv. Fjellgull and the male cv. Apollen,
respectively. Addition of 5.5 μM GA3 reduced the number of shoots. Auxins (IBA, NAA) promoted root development in vitro, but inhibited formation of new shoots. However, as much as 85% of shoots rooted without auxin treatment when planted in
a peat:sand (80:20 v/v) mixture. Some of the male plants regenerated from shoot tip cultures flowered in the greenhouse within
a year after transfer to soil. 相似文献
15.
M. Jain A. S. Nandwal B. S. Kundu B. Kumar I. S. Sheoran N. Kumar A. Mann S. Kukreja 《Biologia Plantarum》2006,50(2):303-306
The plants of pigeonpea (Cajanus cajan L.) cv. H77-216 were subjected to moderate [soil moisture content (SMC) = 7.3 ± 0.5 %] and severe (SMC = 4.3 ± 0.5 %) drought
by withholding the irrigation at vegetative stage (45 d after sowing). The control plants were maintained at SMC of 11.0 ±
0.5 %. Half of the stressed plants were re-irrigated and their recovery was studied after 2 d. Leaf water potential, osmotic
potential, and relative water content of leaf and root decreased significantly while a sharp rise in proline and total soluble
sugars contents were noticed. Drought induced a significant increase in 1-aminocyclopropane 1-carboxylic acid (ACC) content
and ACC oxidase activity which caused a considerable increase in ethylene evolution. Malondialdehyde content and relative
stress injury were increased under drought whereas reverse was true for ascorbic acid content. The membrane integrity of roots
decreased during stress and recovered on rehydration. The specific activity of total superoxide dismutase, ascorbate peroxidase,
glutathione reductase, and glutathione transferase decreased to 37 – 78 %, 17 – 62 %, 29 – 36 % and 57 – 79 % at moderate
and severe drought, respectively. The increase in activity of catalase and peroxidase could not overcome the accumulation
of H2O2 content in the roots. 相似文献
16.
Effects of the superinfection with tobacco mosaic virus (TMV) on susceptible tobacco plants infected with potato virus Y (PVY)
were determined. Dynamic changes in the TMV and/or PVY contents, the ribonucleases (RNases), the phosphomonoesterase (PME),
the phosphodiesterase (PDE) and the glucose-6-phosphate dehydrogenase (G6P DH) activities were studied. The PVY infection
caused a substantial reduction in the multiplication of TMV. The content of TMV in the PVY inoculated leaves amounts to 6
and 9 % in the PVY systemically infected leaves when compared with single TMV. Surprisingly, the challenging virus (TMV) enhanced
the content of inducing virus (PVY) in the locally inoculated leaves up to 130 – 141 %. In contrast, the reduction of PVY
content down to 35 – 40 % by TMV was seen in the PVY systemically infected leaves. The activities of the RNase, the PME, the
PDE and the G6P DH were increased (when compared with the healthy plants) during the acute phase of single virus multiplication
(PVY or TMV). The increase in the activities of the enzymes in the leaves with mixed infection was at least as high as the
sum of the increases of single infections. Moreover, a higher increase than the sum was seen for G6P DH and PDE (by about
20 – 35 %).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Ivan Kosalec Barbara Gregurek Dario Kremer Marijana Zovko Krešimir Sanković Ksenija Karlović 《World journal of microbiology & biotechnology》2009,25(1):145-150
By using HPLC/UV–VIS, Croatian barberry (Berberis croatica Horvat) was found to be a new source of the bioactive alkaloid berberine. Comparison of berberine content in roots, leaves,
and twigs between wild specimens of B. croatica and B. vulgaris collected in Croatia showed that the roots of both species contained the highest berberine content (B. croatica 1.120–1.217%; B. vulgaris 0.805–1.424%), followed by twigs (B. croatica 0.049–0.216%; B. vulgaris 0.077–0.112%). While the berberine content in the leaves of both species was very low (between 0.002% and 0.044%), they were
found to be rich in phenols and flavonols. The Student’s t-test showed a significant difference at P < 0.05 for phenol and flavonol content in the plant organs, both between species and within species. Leaf samples were most
variable, while root samples were the least. Extracts from the roots of both barberry species expressed antimicrobial activity
against Bacillus subtilis NCTC 8236, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10535, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231. Antimicrobial activity of leaf extracts was species-dependent. Root extracts of both species also showed lower
MIC values than other extracts (MIC ≤ 87.5 mg/ml). 相似文献
18.
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
19.
One-year-old apple cuttings (Malus pumila var.domestica cv. M26) were grown for 6 months in pot culture with and without inoculum of the VA-mycorrhizal fungus (VAMF)Glomus macrocarpum in soil from a long-term fertilizer field experiment with different P availability (20, 210, and 280 mg CAL-extractable P
kg−1). The indigenous VAMF propagule density was reduced by 0.5 Mrad X-irradiation. At harvest, non-inoculated and inoculated
plants had similar proportions of root length bearing vesicles. Net dry weight of tree cuttings was significantly increased
by inoculation only at 20 mg P kg−1 (+62%). Increasing P availability from 210 to 280 mg P kg−1 led to a 4-week depression of shoot elongation rate only in the inoculated plants. Uptake of P was significantly enhanced
by inoculation at 20 and 210 mg P kg−1 (+64 and +12%, respectively). On average, inoculated plants had significantly higher concentrations of Zn in leaves and in
roots (+16 and +14%, respectively) and of copper in stems and in roots (+13 and +126%, respectively). Proportion of vesicle
bearing root length was significantly correlated with root caloric content. A lipid content of 0.9–4.5% in the root dry matter
was attributed to the presence of vesicles corresponding to 1.6–8.2% of total root caloric content.
As the control plants were also infected, the beneficial effect of VA-mycorrhiza on nutrient uptake and growth of apple cuttings
was underestimated at all P levels. Furthermore, VAM-potential at the lowest P level was not fully exploited as onset of infection
was most certainly delayed because of a decreased photosynthetic rate due to P deficiency. Energy drain by VAMF-infection
was most probably underestimated considerably, due to, among others, loss of infected root cortex during root growth, sampling
and staining.
It is concluded that apple cuttings rely on VA-mycorrhizal P-uptake at least in low P soils. In high P soils, apple cuttings
may profit predominantly from the uptake of Zn and Cu by the fungal symbionts. 相似文献
20.
Effect of nitrate supply and mycorrhizal inoculation on characteristics of tobacco root plasma membrane vesicles 总被引:1,自引:0,他引:1
Martin Moche Stefanie Stremlau Lars Hecht Cornelia Göbel Ivo Feussner Christine Stöhr 《Planta》2010,231(2):425-436
Plant plasma membrane (pm) vesicles from mycorrhizal tobacco (Nicotiana tabacum cv. Samsun) roots were isolated with negligible fungal contamination by the aqueous two-phase partitioning technique as proven
by fatty acid analysis. Palmitvaccenic acid became apparent as an appropriate indicator for fungal membranes in root pm preparations.
The pm vesicles had a low specific activity of the vanadate-sensitive ATPase and probably originated from non-infected root
cells. In a phosphate-limited tobacco culture system, root colonisation by the vesicular arbuscular mycorrhizal fungus, Glomus mosseae, is inhibited by external nitrate in a dose-dependent way. However, detrimental high concentrations of 25 mM nitrate lead
to the highest colonisation rate observed, indicating that the defence system of the plant is impaired. Nitric oxide formation
by the pm-bound nitrite:NO reductase increased in parallel with external nitrate supply in mycorrhizal roots in comparison
to the control plants, but decreased under excess nitrate. Mycorrhizal pm vesicles had roughly a twofold higher specific activity
as the non-infected control plants when supplied with 10–15 mM nitrate. 相似文献