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1.
Mycorrhizal and nonmycorrhizal roots of Allium schoenoprasum were tested for activities of α-mannosidase, β-glucosidase and arabinosidase. Mannosidase activity was higher by a factor
of two in mycorrhizal than in nonmycorrhizal root extracts. The apparent molecular weight of the enzyme was 152 kDa and its
KM was 1.25 mM in colonized roots and 1.85 mM in uncolonized roots. α-Mannosidase activity was further characterized by an acid
pH optimum and Zn2+ dependency. No significant differences could be found between mycorrhizal and nonmycorrhizal roots for β-glucosidase and
arabinosidase activities.
Accepted: 28 August 1995 相似文献
2.
A. Martins Margarida Santos Helena Santos Maria Salomé Pais 《Trees - Structure and Function》1999,13(3):168-172
31P-Nuclear Magnetic Resonance (NMR) was used to assess phosphate distribution in ectomycorrhizal and nonmycorrhizal roots of
Castanea sativa Mill. as well as in the mycorrhizal fungus Pisolithus tinctorius in order to gain insight into phosphate trafficking in these systems. The fungus P. tinctorius accumulated high levels of polyphosphates during the rapid phase of growth. Mycorrhizal and nonmycorrhizal roots accumulate
orthophosphate. Only mycorrhizal roots presented polyphosphates. The content in polyphosphates increased along the 3 months
of mycorrhiza formation. In mycorrhizal roots of plants cultured under axenic conditions, the orthophosphate pool decreased
along the culture time. In nonmycorrhizal roots the decrease in the orthophosphate content was less pronounced. The level
of orthophosphate in mycorrhizal roots was significantly lower than in nonmycorrhizal ones, which indicates that this system
relies upon the fungal polyphosphates as a major source of phosphate.
Received: 28 July 1998 / Accepted: 21 October 1998 相似文献
3.
Antoni Werner Anna Napierała-Filipiak Marek Mardarowicz Jan Gawdzik 《Acta Physiologiae Plantarum》2004,26(2):187-196
The effect of two substrates differing in the amount of toxic metals and nutrients on the content of volatile organic compounds
in roots of Pinus sylvestris seedlings inoculated with Paxillus involutus, Laccaria laccata, Suillus luteus and a strain of the ectendomycorrhizal fungus Mrg X (Ascomycotina) in pot experiment was investigated. Volatile compounds extracted with a supercritical fluid extraction were primarily terpenes
and sesquiterpenes, and they were qualitatively the same in roots of mycorrhizal and nonmycorrhizal plants grown on both substrates.
The major monoterpenes were α-pinene, Δ3-carene and β-pinene. On the unpolluted substrate, inoculation of plants with the fungi resulted in a similar amount of the
volatiles, while on the polluted substrate the mycorrhizal roots showed significantly lower content of terpenoids than nonmycorrhizal
roots. The mycorrhizal fungi showed different effects on the concentrations of several terpenoids on both substrates. 相似文献
4.
Growth of mycorrhizal tomato and mineral acquisition under salt stress 总被引:19,自引:0,他引:19
G. N. Al-Karaki 《Mycorrhiza》2000,10(2):51-54
High salt levels in soil and water can limit agricultural production and land development in arid and semiarid regions. Arbuscular
mycorrhizal fungi (AMF) have been shown to decrease plant yield losses in saline soils. The objective of this study was to
examine the growth and mineral acquisition responses of greenhouse-grown tomato to colonization by the AMF Glomus mosseae [(Nicol. And Gerd.) Gerd. and Trappe] under varied levels of salt. NaCl was added to soil in the irrigation water to give
an ECe of 1.4 (control), 4.7 (medium) and 7.4 dS m–1 (high salt stress). Plants were grown in a sterilized, low P (silty clay) soil-sand mix. Mycorrhizal colonization was higher
in the control than in saline soil conditions. Shoot and root dry matter yields and leaf area were higher in mycorrhizal than
in nonmycorrhizal plants. Total accumulation of P, Zn, Cu, and Fe was higher in mycorrhizal than in nonmycorrhizal plants
under both control and medium salt stress conditions. Shoot Na concentrations were lower in mycorrhizal than in nonmycorrhizal
plants grown under saline soil conditions. The improved growth and nutrient acquisition in tomato demonstrate the potential
of AMF colonization for protecting plants against salt stress in arid and semiarid areas.
Accepted: 21 February 2000 相似文献
5.
A. R. Hashem 《Mycorrhiza》1995,5(4):289-291
The role of mycorrhizal infection in the resistance of Vaccinium macrocarpon to manganese was investigated in perlite culture containing nutrient solution amended with Mn at 0, 250, 500 or 1000 g/ml. Shoot and root dry weights of the mycorrhizal plants were higher than nonmycorrhizal plants. The mycorrhizal plants produced significantly longer main roots than the nonmycorrhizal plants. Differences between shoot and root Mn concentrations of mycorrhizal and nonmycorrhizal plants arose by reduction of Mn in the leaves of mycorrhizal plants and a corresponding increase in root tissues. 相似文献
6.
Rough lemon seedlings were grown in mycorrhizal-infested or phosphorus-amended soil (25 and 300 mg P/kg) in greenhouse experiments. Plants Were inoculated with the citrus burrowing nematode, Radopholus citrophilus (0, 50, 100, or 200 nematodes per pot). Six months later, mycorrhizal plants and nonmycorrhizal, high-P plants had larger shoot and root weights than did non-mycorrhizal, low-P plants. Burrowing nematode population densities were lower in roots of mycorrhizal or nonmycorrhizal, high-P plants than in roots of nonmycorrhizal, low-P plants; however, differences in plant growth between mycorrhizal and nonmycorrhizal plants were not significant with respect to initial nematode inoculum densities. Phosphorus content in leaf tissue was significantly greater in mycorrhizal and nonmycorrhizal, high-P plants compared with nonmycorrhizal, low-P plants. Nutrient concentrations of K, Mg, and Zn were unaffected by nematode parasitism, whereas P, Ca, Fe, and Mn were less in nematode-infected plants. Enhanced growth associated with root colonization by the mycorrhizal fungus appeared to result from improved P nutrition and not antagonism between the fungus and the nematode. 相似文献
7.
The response of peanut to salt (NaCl) and acid (HCl) stress was studied in association with Glomus caledonium, an arbuscular mycorrhizal (AM) fungus. The plants were exposed to salt stress by irrigation on alternate days with 1% or
5% NaCl solutions, or with 0.1 N HCl to induce acid stress. Plant yield almost tripled in mycorrhizal plants compared with
nonmycorrhizal control plants. AM inoculation significantly increased plant yield and biomass at 1% NaCl, while at 5% NaCl
AM was less effective in alleviating salt stress. Percentage AM colonization was also lowest at 5% NaCl. AM inoculation was
found to promote the establishment of peanut plants under acid stress conditions.
Accepted: 2 October 1995 相似文献
8.
Anna Napierała-Filipiak Antoni Werner Marek Mardarowicz Jan Gawdzik 《Acta Physiologiae Plantarum》2002,24(2):137-143
The effect of Paxillus involutus, Laccaria laccata, Suillus luteus, S. bovinus, Hebeloma crustuliniforme and a strain of the ectendomycorrhizal fungus Mrg X (Ascomycotina) on the content of volatile organic compounds in roots of Pinus sylvestris seedlings grown in vitro was investigated. Volatile compounds extracted with a supercritical fluid extraction were primarily terpenes and sesquiterpenes
and qualitatively were the same in roots of mycorrhizal and nonmycorrhizal plants. The major monoterpenes were α-pinene, Δ3-carene and β-pinene. Inoculation of plants with the fungi resulted in statistically non-significant increases in the total
amount of the volatiles. The mycorrhizal fungi showed diversified effect on the concentrations of several terpenoids. 相似文献
9.
Effects of arbuscular mycorrhizal fungi and drought stress on growth and nutrient uptake of two wheat genotypes differing in drought resistance 总被引:1,自引:0,他引:1
The effects of an arbuscular mycorrhizal (AM) fungus and drought stress on the growth, phosphorus, and micronutrient uptake
of two wheat genotypes exhibiting differences in drought resistance were investigated. Plants were grown on a low P (4 mg
kg–1 soil) silty clay (Typic Xerochrept) soil-sand mix. Mycorrhizal infection was higher under well-watered than under dry soil
conditions and the drought-resistant genotype CR057 had a higher mycorrhizal colonization than the drought-sensitive genotype
CR006. Total and root dry matter yields and total root length were higher in mycorrhizal than in nonmycorrhizal plants of
both genotypes. CR057 had higher total dry matter but not root dry matter than CR006 plants. The enhancement in total dry
matter due to AM inoculation was 42 and 39% under well-watered and 35 and 45% under water-stressed for CR057 and and CR006,
respectively. For both genotypes, the contents of P, Zn, Cu, Mn, and Fe were higher in mycorrhizal than in nonmycorrhizal
plants and higher under well-watered than under dry soil conditions. The enhancement of P, Zn, Cu, Mn, and Fe uptake due to
AM inoculation was more pronounced in CR006 than in CR057, particularly under water-stressed conditions. Thus CR006 benefitted
from AM infection more than the CR057 under dry soil conditions, despite the fact that CR057 roots were highly infected. It
appears that CR006 is more dependent on AM symbiosis than CR057.
Accepted: 12 February 1997 相似文献
10.
Moisture retention properties of a mycorrhizal soil 总被引:1,自引:0,他引:1
The water relations of arbuscular mycorrhizal plants have been compared often, but virtually nothing is known about the comparative water relations of mycorrhizal and nonmycorrhizal soils. Mycorrhizal symbiosis typically affects soil structure, and soil structure affects water retention properties; therefore, it seems likely that mycorrhizal symbiosis may affect soil water relations. We examined the water retention properties of a Sequatchie fine sandy loam subjected to three treatments: seven months of root growth by (1) nonmycorrhizal Vigna unguiculata given low phosphorus fertilization, (2) nonmycorrhizal Vigna unguiculata given high phosphorus fertilization, (3) Vigna unguiculata colonized by Glomus intraradices and given low phosphorus fertilization. Mycorrhization of soil had a slight but significant effect on the soil moisture characteristic curve. Once soil matric potential (m) began to decline, changes in m per unit change in soil water content were smaller in mycorrhizal than in the two nonmycorrhizal soils. Within the range of about –1 to –5 MPa, the mycorrhizal soil had to dry more than the nonmycorrhizal soils to reach the same m. Soil characteristic curves of nonmycorrhizal soils were similar, whether they contained roots of plants fed high or low phosphorus. The mycorrhizal soil had significantly more water stable aggregates and substantially higher extraradical hyphal densities than the nonmycorrhizal soils. Importantly, we were able to factor out the possibly confounding influence of differential root growth among mycorrhizal and nonmycorrhizal soils. Mycorrhizal symbiosis affected the soil moisture characteristic and soil structure, even though root mass, root length, root surface area and root volume densities were similar in mycorrhizal and nonmycorrhizal soils. 相似文献
11.
Psidium guajava L.) plantlets was determined during acclimatization and plant establishment. Guava plantlets were asexually propagated through
tissue culture and grown in a glasshouse for 18 weeks. Half of the plantlets were inoculated with a mixed endomycorrhiza isolate
from Mexico, ZAC-19, containing Glomus diaphanum, G. albidum and G. claroides. Plantlets were fertilized with modified Long Ashton nutrient solution that supplied 11 μg P ml−1. Gas exchange measurements were taken at 2, 4, 8, and 18 weeks after inoculation using a portable photosynthesis system.
All micropropagated guava plantlets survived transplant shock. After 6 weeks, mycorrhizal plantlets had greater shoot growth
rates and leaf production than non-mycorrhizal plantlets. This also corresponded with increased photosynthetic rates and stomatal
conductance of mycorrhizal plants. By 18 weeks, mycorrhizal plantlets had greater shoot length, leaf area, leaf, stem, and
root dry mass. However, gas exchange was comparable among treatments, in part because the container size was restricting growth
of the larger mycorrhizal plantlets. Non-mycorrhizal plantlets had greater leaf area ratios and specific leaf areas than mycorrhizal
plantlets. Increased leaf tissue mineral levels of P, Mg, Cu, and Mo also occurred with mycorrhizal plantlets. Roots of inoculated
guava plantlets were heavily colonized with arbuscules, vesicles and endospores. Guava plantlets were highly mycotrophic with
a mycorrhizal dependency index of 103%.
Accepted: 27 December 1999 相似文献
12.
Summary Studies examined net photosynthesis (Pn) and dry matter production of mycorrhizal and nonmycorrhizalPinus taeda at 6 intervals over a 10-month period. Pn rates of mycorrhizal plants were consistently greater than nonmycorrhizal plants, and at 10 months were 2.1-fold greater. Partitioning of current photosynthate was examined by pulse-labelling with14CO2 at each of the six time intervals. Mycorrhizal plants assimilated more14CO2, allocated a greater percentage of assimilated14C to the root systems, and lost a greater percentage of14C by root respiration than did nonmycorrhizal plants. At 10 months, the quantity of14CO2 respired by roots per unit root weight was 3.6-fold greater by mycorrhizal than nonmycorrhizal plants. Although the stimulation of photosynthesis and translocation of current photosynthate to the root system by mycorrhiza formation was consistent with the source-sink concept of sink demand, foliar N and P concentrations were also greater in mycorrhizal plants.Further studies examined Pn and dry matter production ofPinus contorta in response to various combinations of N fertilization (3, 62, 248 ppm), irradiance and mycorrhizal fungi inoculation. At 16 weeks of age, 6 weeks following inoculation with eitherPisolithus tinctorius orSuillus granulatus, Pn rates and biomass were significantly greater in mycorrhizal than nonmycorrhizal plants. Mycorrhizal plants had significantly greater foliar %P, but not %N, than did nonmycorrhizal plants. Fertilization with 62 ppm N resulted in greater mycorrhiza formation than either 3 or 248 ppm. Increased irradiance resulted in increased mycorrhiza formation. 相似文献
13.
Effects of inoculation with the arbuscular mycorrhizal (AM) fungus Glomus mosseae on the behavior of Hg in soil–plant system were investigated using an artificially contaminated soil at the concentrations
of 0, 1.0, 2.0, and 4.0 mg Hg kg−1. Mercury accumulation was lower in mycorrhizal roots than in nonmycorrhizal roots when Hg was added at the rates of 2.0 and
4.0 mg kg−1, while no obvious difference in shoot Hg concentration was found between mycorrhizal and nonmycorrhizal treatments. Mycorrhizal
inoculation significantly decreased the total and extractable Hg concentrations in soil as well as the ratio of extractable
to total Hg in soil. Equilibration sorption of Hg by soil was investigated, and the results indicated that mycorrhizal treatment
enhanced Hg sorption on soil. The uptake of Hg was lower by mycorrhizal roots than by nonmycorrhizal roots. These experiments
provide further evidence for the role of mycorrhizal inoculation in increasing immobilization of Hg in soil and reducing the
uptake of Hg by roots. Calculation on mass balance of Hg in soil suggests the presence of Hg loss from soil presumably through
evaporation, and AM inoculation enhanced Hg evaporation. This was evidenced by a chamber study to detect the Hg evaporated
from soil. 相似文献
14.
A pot experiment was conducted to examine the effect of arbuscular mycorrhizal fungus, Glomus fasciculatum, and salinity on the growth of Acacia nilotica. Plants were grown in soil under different salinity levels (1.2, 4.0, 6.5, and 9.5 dS m−1). In saline soil, mycorrhizal colonization was higher at 1.2, 4.0, and 6.5 dS m−1 salinity levels in AM-inoculated plants, which decreased as salinity levels further increased (9.5 dS m−1). Mycorrhizal plants maintained greater root and shoot biomass at all salinity levels compared to nonmycorrhizal plants.
AM-inoculated plants had higher P, Zn, and Cu concentrations than uninoculated plants. In mycorrhizal plants, nutrient concentrations
decreased with the increasing levels of salinity, but were higher than those of the nonmycorrhizal plants. Mycorrhizal plants
had greater Na concentration at low salinity levels (1.2, 4.0 dS m−1), which lowered as salinity levels increased (6.5, 9.5 dS m−1), whereas Na concentration increased in control plants. Mycorrhizal plants accumulated a higher concentration of K at all
salinity levels. Unlike Na, the uptake of K increased in shoot tissues of mycorrhizal plants with the increasing levels of
salinity. Our results indicate that mycorrhizal fungus alleviates deleterious effects of saline soils on plant growth that
could be primarily related to improved P nutrition. The improved K/Na ratios in root and shoot tissues of mycorrhizal plants
may help in protecting disruption of K-mediated enzymatic processes under salt stress conditions. 相似文献
15.
Nanna Rasmussen David C. Lloyd R. George Ratcliffe Poul Erik Hansen Iver Jakobsen 《Plant and Soil》2000,226(2):245-253
31P nuclear magnetic resonance (NMR) spectroscopy was used to study phosphate (P) metabolism in mycorrhizal and nonmycorrhizal
roots of cucumber (Cucumis sativus L) and in external mycelium of the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck & Smith. The in vivo NMR method allows biological systems to be studied non-invasively and non-destructively. 31P NMR experiments provide information about cytoplasmic and vacuolar pH, based on the pH-dependent chemical shifts of the
signals arising from the inorganic P (Pi) located in the two compartments. Similarly, the resonances arising from α, β and γ phosphates of nucleoside triphosphates (NTP) and nucleoside diphosphates (NDP) supply knowledge about the metabolic activity
and the energetic status of the tissue. In addition, the kinetic behaviour of P uptake and storage can be determined with
this method. The 31P NMR spectra of excised AM fungi and mycorrhizal roots contained signals from polyphosphate (PolyP), which were absent in
the spectra of nonmycorrhizal roots. This demonstrated that the Pi taken up by the fungus was transformed into PolyP with a short chain length. The spectra of excised AM fungi revealed only
a small signal from the cytoplasmic Pi, suggesting a low cytoplasmic volume in this AM fungus.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Seedlings of papaya (Carica papaya L. var. Solo) were transplanted to pots with or without an arbuscular mycorrhizal (AM) fungus (Gigaspora margarita Becker and Hall). After 3 months, half the plants were subjected to water stress by withdrawing irrigation. The leaf water
potential (LWP) was measured during 20 days of water-stress treatment and then the plants were harvested. Root ethylene and
1-aminocyclopropane-1-carboxylic acid (ACC) concentrations were measured and plant fresh weight determined. The LWP decreased
during the water-stress treatment and this decrease was more severe in the non-AM plants. Plant fresh weight was higher for
AM than non-AM plants under both conditions. Under well-irrigated conditions, the ethylene concentration in the roots was
increased by the presence of AM, although there was no significant difference between AM and non-AM roots in ACC levels. ACC
increased in both AM and non-AM roots under water-stress conditions. The water-stress treatment resulted in a marked increase
in ethylene concentration in non-AM roots but the concentration in AM roots was slightly lower than under normal conditions.
Accepted: 7 July 2000 相似文献
17.
Summary Shoot water relations and carbohydrate levels were compared for droughted nonmycorrhizal and vesicular-arbuscular (VA) mycorrhizalRosa hybrida L. cv ‘Samantha’ plants grown with high and low phosphorus fertilization. Leaf diffusive conductance (g
i
) of plants colonized byGlomus intraradices Schenk and Smith andGlomus deserticola Trappe, Bloss and Menge were 2 × and 1.5× greater, respectively, than in nonmycorrhizal plants. Regardless of P fertilization,
leaf osmotic and bulk water potentials were 0.5 to 1.1 MPa higher in mycorrhizal than in nonmycorrhizal plants. Leaf starch,
chlorophyll and water contents while fructose, glucose and total soluble carbohydrates were lower. Level of P fertilization
had no effect on water relations or soluble carbohydrate content of nonmycorrhizal roses. The water status of droughted rose
was impoved more byG. intraradices than byG. deserticola.
Washington State University College of Agriculture and Home Economics Research Center Scientific Paper No. 7375. 相似文献
18.
We propose that mycorrhizal colonization of roots alters nonhydraulic root to shoot communication of soil drying. Split-root rose (Rosa hybrida L. cv Samantha) plants—one side of the root system colonized by Glomus intraradices Schenck & Smith, the other side nonmycorrhizal—displayed different stomatal conductances upon partial drying, depending upon whether mycorrhizal or nonmycorrhizal roots were dried. No differences in leaf water status were observed among control plants and those whose mycorrhizal or nonmycorrhizal roots were dried. 相似文献
19.
Element distribution in mycorrhizal and nonmycorrhizal roots of the halophyte Aster tripolium determined by proton induced X-ray emission 总被引:2,自引:0,他引:2
Summary. The salt aster (Aster tripolium L.) colonized by the arbuscular mycorrhizal fungus Glomus intraradices Sy167 and noncolonized control plants were grown in a greenhouse for nine months with regular fertilization by Hoagland nutrient solution supplemented with 2% NaCl. Mycorrhizal roots showed a high degree of mycorrhizal colonization of 60–70% and formed approximately 25% more dry weight and much less aerenchyma than the nonmycorrhizal controls. Cryosectioning essentially preserved the root cell structures and apparently did not cause significant ion movements within the roots during cuttings. The experimental conditions, however, did not allow to discriminate between fungal and plant structures within the roots. Quantification of proton-induced X-ray emission (PIXE) data revealed that in control roots, Na+ was mainly concentrated in the outer epidermal and exodermal cells, whereas the Cl– concentration was about the same in all cells of the roots. Cross sections of roots colonized by the mycorrhizal fungus did not show this Na1 gradient in the concentration from outside to inside but contained a much higher percentage of NaCl among the elements determined than the controls. PIXE images are also presented for the four other elements K, P, S, and Ca. Both in colonized and control roots, the concentration of potassium was high, probably for maintaining homoeostasis under salt stress. This is seemingly the first attempt to localize both Na+ and Cl– in a plant tissue by a biophysical method and also demonstrates the usefulness of PIXE analysis for such kind of investigation. 相似文献
20.
Accumulation of sesquiterpenoid cyclohexenone derivatives induced by an arbuscular mycorrhizal fungus in members of the Poaceae 总被引:7,自引:0,他引:7
Sixty one members of the Poaceae, including various cereals, were grown in defined nutrient media with and without the arbuscular
mycorrhizal (AM) fungus, Glomus intraradices Schenk & Smith. The roots of all species investigated were colonized by the AM fungus, however, to different degrees and
independent of their systematic position. High-performance liquid chromatographic analyses of methanolic extracts from the
roots of mycorrhizal and nonmycorrhizal species revealed dramatic changes in the patterns of UV-detectable products along
with a widespread occurrence of AM-fungus-induced accumulation of sesquiterpenoid cyclohexenone derivatives. The latter occur
most often in the tribes Poeae, Triticeae and Aveneae. Some additional control experiments on plant infection with pathogens
(Gaeumannomyces graminis) and Drechslera sp.) or an endophyte (Fusarium sp.), as well as application of abiotic stress, proved that the metabolism of these terpenoids is part of a response pattern
of many gramineous roots in their specific reaction to AM fungal colonization.
Received: 23 October 1996 / Accepted 11 December 1996 相似文献