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1.
The root systems of cucumber (Cucumis sativus L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) plants were subjected to a short-term (6–7-h-long) treatment with low and high temperatures, sodium chloride, and lead nitrate, and the effect of these treatments on the changes in the cold- and heat-tolerance of leaf cells was determined. It was established that chilling of cucumber and wheat seedling roots at 10 and 2°C, respectively, or their heating at 38°C and 40°C, respectively, induced an increase in both cold- and heat-tolerance of leaf cells. An increase in the cold- and heat-tolerance was also observed in roots treated with sodium chloride at concentrations of 0.15 M (cucumber) and 0.2 M (wheat), as well as with lead nitrate at a concentration of 0.1 mM (barley, wheat). The tolerance increase induced by these stress agents was accompanied by a considerable increase in the ABA concentration in leaves. The effect of physical and chemical stress agents is suggested to induce the same nonspecific changes in the aboveground organs. These changes bring about, directly or indirectly, an increase in the cold- and heat-tolerance and are related to an increase in the ABA content. 相似文献
2.
The effects of heating at 38°C of whole cucumber (Cucumis sativus L.) seedlings or local heating of their shoots and roots on ABA content and heat tolerance of leaves and roots were investigated. During the initial period of the high-temperature treatment of whole seedlings, the ABA concentration in leaves and roots increased considerably. Local heating of the shoot or root resulted in an increase in the ABA concentration not only in the heated organ, but also in unheated seedling parts. A high-temperature treatment of the whole seedlings and the local treatment of shoots or roots caused an increase in the heat tolerance of leaf cells. The heat tolerance of root cells virtually did not change after heating of the whole seedlings or shoots, but decreased after heating of roots. The possible role of ABA in changing the heat tolerance of leaf and root cells by local heating of the seedling is discussed. 相似文献
3.
H. Kato-Noguchi 《Biologia Plantarum》2000,43(4):621-624
Maize (Zea mays L.) seedlings were exposed to osmotic stress, and alcohol dehydrogenase (ADH) activity and abscisic acid (ABA) concentration were determined. The osmotic stress increased ADH activities in both roots and shoots, whereas the increase was 2-fold greater in roots than the shoots. The stress also increased ABA concentration in both roots and shoots and the increase was greater in the roots than in the shoots. 相似文献
4.
Y.M. Angelova S.G. Petkova N.I. Popova B.J. Stefanov L.K. Iliev 《Biologia Plantarum》2002,45(1):33-37
The experiments were carried out with germinating maize seeds (Zea mays L.), grown 6 d in the dark at 26°C. Before germination the seeds were soaked for 4 h in solutions containing 1 mM abscisic acid (ABA), 0.1 mM N1-(2-chloro-4-pyridyl)-N2 phenylurea (4PU-30) and their combination. The influence of plant growth regulators on the length, fresh (FM) and dry (DM) masses, proteolytic activities and soluble protein fractions in shoots, roots and endosperm were studied. As compared to control the seedlings treated with ABA showed lower length, FM and DM of shoots and roots, and lower proteolytic activities. As a consequence of suppression of both growth and protein breakdown, these seedlings possessed higher protein content in endosperm. 4PU-30 partially decreased the ABA suppressing effects. 相似文献
5.
G. V. Hoad 《Planta》1975,124(1):25-29
Summary Addition of an osmoticum (-12 bars) to the rooting medium of sunflowers (Helianthus annuus L.) caused an increase in the level of abscisic acid (ABA) present in xylem exudate subsequently collected from cut shoots. Using tall and dwarf plants it was shown that there was a time lag in the appearance of increased levels of ABA in tall plants when compared with dwarf plants. The results indicate that the leaves, rather than the roots are the site of synthesis of ABA present in the xylem sap of osmotically stressed sunflower plants.Abbreviation ABA
abscisic acid 相似文献
6.
Hisashi Kato-Noguchi 《Acta Physiologiae Plantarum》2001,23(1):49-53
The n-hexane-, acetone- and water-soluble fractions obtained from an aqueous acetone extract of lemon balm (Melissa officinalis L.) shoots inhibited the germination and the growth of roots and shoots of cockscomb (Amaranthus caudatus L.), cress (Lepidium sativum L.), crabgrass (Digitaria sanguinalis L.), timothy (Phleum pratense L.), lettuce (Lactuca sativa L.) and ryegrass (Lolium multiflorum Lam.). The inhibitory activity of the water-soluble fraction was the greatest, followed by that of acetone- and n-hexane-soluble fractions in all bioassays. The effectiveness of these fractions on the roots was greater than that of the
shoots of the test plants. Significant reductions in the germination and growth of the roots and shoots were observed as the
extract concentration increased. Such rate-dependent responses of the test plants to the fractions suggest that each fraction
might contain allelochemical(s), but that the greatest potential was in the water-soluble fraction. 相似文献
7.
Hisashi Kato-Noguchi 《Acta Physiologiae Plantarum》1999,21(4):341-344
In order to clarify the induction of alcohol dehydrogenase (ADH) by anaerobiosis in oat (Avena sativa L.), the seedlings were exposed to anaerobiosis and activity of ADH and ADH isozyme profiles were determined. The anaerobiosis
increased ADH activities in shoots and roots of the seedlings. By day 2, the activity increased 5 and 4 times in the roots
and the shoots, respectively, compared with those under aerobic condition. Based on nondenaturing electrophoresis, ADH isozyme
composition analysis revealed six bands consisting of a dimmer enzyme with submits encoded by three different Adh genes. Changes in staining intensity of the isozymes indicated that the increase in ADH activity in oat under anaerobiosis
resulted from increased enzyme synthesis. 相似文献
8.
Exogenously applied ABA-β-d-glucopyranosyl ester (ABA-GE) inhibited shoot growth of alfalfa (Medicago sativa L.), cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), Digitaria sanguinalis L., timothy (Pheleum pratense L.) and ryegrass (Lolium multiflorum Lam.) seedlings at concentrations greater than 0.1 μM. The growth inhibitory activity of ABA-GE on these shoots was 26–40% of
that of (+)-ABA. ABA-β-d-glucosidase activities in these seedlings were 11–31 nmol mg−1 protein min−1. These results suggests that exogenously applied ABA-GE may be absorbed by plant roots and hydrolyzed by ABA-β-d-glucosidase, and liberated free ABA may induce the growth inhibition in these plants. Thus, although ABA-GE had been thought
to be physiologically inactive ABA conjugate, ABA-GE may have important physiological functions rather than an inactive conjugated
ABA form. 相似文献
9.
Salt-induced protein synthesis in tomato roots: the role of ABA 总被引:5,自引:1,他引:4
The role played by abscisic acid (ABA) in regulating salt-induced protein
synthesis was investigated in roots of tomato (Lycopersicon
esculentum Mill. cv. Ailsa Craig). Roots of 9-d-old Ailsa Craig
(AC) seedlings and the near-isogenic ABA-deficient mutant,
flacca (flc), were exposed to
salt which elicited the appearance of novel polypeptides and both repressed
and enhanced the synthesis of others. The polypeptide profiles of
salt-treated AC and flc roots were similar suggesting
that the synthesis of most novel polypeptides in salt-treated roots is not
dependent on an elevated level of endogenous ABA. Exogenous ABA and a
combined ABA/salt treatment were applied to the roots of AC and
flc. Exogenous ABA, in the absence of salt, induced
the accumulation of several polypeptides that were unique to this treatment
as well as a subset of those synthesized in salt-treated roots.
Interestingly, in roots exposed to the combined ABA/salt treatment, only
those polypeptides that accumulated in both ABA or salt-treated roots were
synthesized. Endogenous ABA levels increased 2-fold in salt-treated AC
roots and 14-fold in salt-treated flc roots. Although
the absolute level of ABA was lower in salt-treated
flc than in AC, this demonstrates that
flc has the capacity to accumulate some ABA in its
roots following a salt treatment. Since it is possible that this level of
ABA was sufficient to induce the changes in polypeptide synthesis observed
in salt-treated roots of flc, the salt-induced
accumulation of endogenous ABA was prevented by treating AC roots with
fluridone. In these roots, the set of salt-induced polypeptides was similar
to that observed in salt-treated roots indicating that an elevated level of
endogenous ABA may not play a major role in regulating the accumulation of
most salt-induced proteins in tomato roots.Keywords:
Salt stress, ABA, polypeptide synthesis, roots.
相似文献
10.
Abscisic acid (ABA) is recognised as an important hormone involved in root-to-shoot communication of drought stress in plants.
This study aimed to determine whether isolated roots can produce both free and conjugated ABA (ABA–glucose ester) and whether
Lupinus species vary in the synthesis of ABA in the roots when dehydrated. The concentration of free and conjugated ABA at 100 and
50% root water content was measured in the distal 10 mm of the roots of 3- to 5-day-old seedlings of seven Lupinus species with and without 10−5 M tetcyclacis, an inhibitor of the oxidative breakdown of ABA. When the root tips were exposed to tetcyclacis, the concentration
of free ABA increased by 20% on average, suggesting that oxidative breakdown of free ABA was limited in the isolated Lupinus roots. The concentration of free ABA of the fully hydrated plants varied significantly among genotypes and more than doubled
on average across genotypes with dehydration of the root tips to 50% water content. The concentration of conjugated ABA also
varied significantly with species, but was only one-tenth the concentration of free ABA in the roots and did not change significantly
with root dehydration or the inhibition of oxidative metabolism. The production of free ABA in response to the water deficit
varied with species from +470% in L. digitatus to +33% in L. angustifolius. The small concentration and lack of increase of conjugated ABA with water deficit suggests that it is unlikely to have an
important role as a root signal in response to soil drying in Lupinus species. 相似文献
11.
Root and Shoot Growth of Plants Treated with Abscisic Acid 总被引:4,自引:0,他引:4
Young seedlings of Capsicum annum L., Commelina communis L.and maize (Zea mays L.) were subjected to a mild water-stressingtreatment and/or treated with abscisic acid (ABA). Plants rootedin soil received a soil-drying treatment and their leaves weresprayed with a 104 M solution of ABA. Plants grown insolution culture were stressed by the addition of polyethyleneglycol (PEG) to the rooting medium and ABA was also added tothe rooting medium, either with or without PEG. The effectsof both treatments on the growth of roots and shoots and theultimate root: shoot dry weight ratio were very similar. Shootgrowth was limited both by water stress and by ABA application;while there was some evidence that mild water stress and/orABA application may have resulted in a stimulation of root growth.More severe water stress reduced the growth of roots but theoverall effect of stress was to increase the ratio of rootsto shoots. Capsicum annum L., Commelina communis L., Zea mays L., water stress, abscisic acid 相似文献
12.
The effect of 4-amino,3,5,6-trichloropicolinic acid (picloram) on transport from leaves to the roots was studied using young bean (Phaseolus vulgaris L.), mesquite (Prosopis juliflora var. velutina (Woot.) Sarg.), and huisache (Acacia farnesiana (L) Willd.) plants. The only picloram treatments which were effective in enhancing transport of 14C-assimilate or 14C-picloram to the roots were those made to the shoots or roots one day or more before application of the label to the shoots. The enhancement of transport was not evident when un-labeled picloram or 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), or both, were applied at the same time as the 14C-label. Enhancement of transport was to the more mature stem or root tissues. Inorganic nitrogen applied to nitrogen-deficient bean plants also increased transport of 14C-assimilate to the roots, especially the rate. 相似文献
13.
14.
Grafted plants of flacca, an ABA-deficient mutant of tomato (Lycopersicon esculentum), and the wild-type variety Rheinlands Ruhm were grown with and without salinity stress to test the roles of roots and shoots in the regulation of plant growth. Fourteen days after exposure to 200 mM NaCl, shoot and root fresh weight, endogenous ABA concentrations, nitrate concentration, activities of selected enzymes related to nitrogen assimilation, and cation accumulation were determined. Rootstock genotype had little influence on the growth of the grafted plants, whereas grafted plants having wild-type shoots (Ws) produced more biomass than those having flacca shoots (Fs), irrespective of the salinity level. Growth of flacca shoots grafted onto wild-type rootstock (Fs/Wr) was superior to that of flacca shoots grafted onto flacca rootstock (Fs/Fr). The improved growth correlated with enhanced levels of ABA in the flaccashoots of Fs/Wr. In all the graft combinations, ABA content was higher in wild-type shoots than in flacca shoots, with or without salinity. There were no significant differences in root ABA concentrations among the different grafted types. Enhanced growth correlated with higher nitrate levels and higher nitrate reductase activity in the roots and shoots of plants with wild-type shoots and with higher shoot concentrations of ABA in plants with wild-type shoots. There were no significant differences in glutamine synthetase and phosphoenol pyruvate carboxylase activities in the shoots and roots of all the grafted plants, regardless of the salinity level. While shoot genotype determined the accumulation of K+ and Na+ in grafted plants regardless of salinity, it had no influence on Ca2+ concentrations. Regardless of the salinity, the total concentration of cations was the same in all the plants, while salinity decreased Mg2+ concentration in roots and shoots of all grafts, with the exception of flacca grafted shoots. The scion genotype – and its ABA level – thus played the major role in the growth of grafted plants, regardless of the rootstock genotype and the salinity of the growth medium. 相似文献
15.
Effect of abscisic acid application on root isoflavonoid concentration and nodulation of wild-type and nodulation-mutant soybean plants 总被引:1,自引:0,他引:1
Isoflavonoids (daidzein, genistein, and coumestrol) are involved in induction of nod genes in Bradyrhizobium japonicum and may be involved in nodule development as well. Abscisic acid (ABA) may also impact nodulation since ABA is reportedly
involved in isoflavonoid synthesis. The current study was conducted to evaluate whether ABA plays a role in differential nodulation
of a hypernodulated soybean (Glycine max L. Merr.) mutant and the Williams parent. Exogenous ABA application resulted in a decrease in nodule number and weight in
both lines. Isoflavonoid concentrations were also markedly decreased in response to ABA application in both inoculated and
noninoculated soybean roots. The inoculation treatment itself resulted in a marked increase in isoflavonoid concentrations
of NOD1-3, regardless of ABA levels, while only slight increases occurred in Williams. The nodule numbers of both soybean
lines across several ABA concentration treatments were highly correlated with the concentration of all three isoflavonoids.
However, differences in internal levels of ABA between lines were not detected when grown in the absence of external ABA additions.
It is concluded that differential nodule expression between the wild type and the hypernodulated mutant is not likely due
to differential ABA synthesis. 相似文献
16.
The growth regulator Stifun at all concentrations tested (0.033, 0.33, 3.3, and 33 mg/L) affected the hormonal status of wheat
seedlings (Triticum aestivum L., cv. Zhnitsa) and stimulated plant growth. This was evident in activation of cell division and elongation, as well as
in the increase in shoot and root length, water content, and dry weight. Effects of Stifun on roots and shoots depended on
concentration. Application of Stifun at the optimal growth-stimulating concentration (0.033 mg/L) elevated the levels of zeatin,
zeatin riboside, dihydrozeatin riboside, isopentenyladenosine, and IAA in roots of 2-day-old seedlings, but reduced the ABA
content. The levels of ABA, IAA, dihydrozeatin, and dihydrozeatin riboside in shoots increased, while the levels of zeatin
riboside, isopentenyl adenine, and isopentenyladenosine decreased. The results indicate that the hormonal system plays a part
in the plant response to growth-stimulating action of Stifun. 相似文献
17.
Phytohormones in Seedlings of Maize Hybrids Differing in Their Tolerance to High Temperatures 总被引:1,自引:0,他引:1
Musatenko L. I. Vedenicheva N. P. Vasyuk V. A. Generalova V. N. Martyn G. I. Sytnik K. M. 《Russian Journal of Plant Physiology》2003,50(4):444-448
The contents of phytohormones (IAA, ABA, cytokinins, and gibberellin-like compounds) were measured in shoots and roots of eight-day-old seedlings of two maize (Zea mays L.) hybrids differing in their tolerance to elevated temperatures. More tolerant seedlings initially contained more ABA and cytokinins, and the contents of these hormones changed less after a temperature increase than in seedlings of the sensitive hybrid. Hyperthermia induced a destruction of chloroplast lamellar structure in the leaf sheath cells of the sensitive but not of the tolerant hybrid. 相似文献
18.
Trivalent chromium (Cr3+) is essential for animal and human health, whereas hexavalent Cr (CrO4
2−) is a potent carcinogen and extremely toxic to animals and humans. Thus, the accumulated Cr in food plants may represent
potential health hazards to animals and humans if the element is accumulated in the hexavalent form or in high concentrations.
This study was conducted to determine the extent to which various vegetable crops absorb and accumulate Cr3+ and CrO4
2− into roots and shoots and to ascertain the different chemical forms of Cr in these tissues. Two greenhouse hydroponic experiments
were performed using a recirculating-nutrient culture technique that allowed all plants to be equally supplied with Cr at
all times. In the first experiment, 1 mg L−1 Cr was supplied to 11 vegetable plant species as Cr3+ or CrO4
2−, and the accumulation of Cr in roots and shoots was compared. The crops tested included cabbage (Brassica oleracea L. var. capitata L.), cauliflower (Brassica oleracea L. var. botrytis L.), celery (Apium graveolens L. var. dulce (Mill.) Pers.), chive (Allium schoenoprasum L.), collard (Brassica oleracea L. var. acephala DC.), garden pea (Pisum sativum L.), kale (Brassica oleracea L. var. acephala DC.), lettuce (Lactuca sativa L.), onion (Allium cepa L.), spinach (Spinacia oleracea L.), and strawberry (Fragaria ×
ananassaDuch.). In the second experiment, X-ray absorption spectroscopy (XAS) analysis on Cr in plant tissues was performed in roots
and shoots of various vegetable plants treated with CrO4
2− at either 2 mg Cr L−1 for 7 d or 10 mg Cr L−1 for 2, 4 or 7 d. The crops used in this experiment included beet (Beta vulgaris L. var. crassa (Alef.) J. Helm), broccoli (Brassica oleracea L. var. Italica Plenck), cantaloupe (Cucumis melo L. gp. Cantalupensis), cucumber (Cucumis sativus L.), lettuce, radish (Raphanus sativus L.), spinach, tomato (Lycopersicon lycopersicum (L.) Karsten), and turnip (Brassica rapa L. var. rapifera Bailey). The XAS speciation analysis indicates that CrO4
2− is converted in the root to Cr3+ by all plants tested. Translocation of both Cr forms from roots to shoots was extremely limited and accumulation of Cr by
roots was 100-fold higher than that by shoots, regardless of the Cr species supplied. Highest Cr concentrations were detected
in members of the Brassicaceae family such as cauliflower, kale, and cabbage. Based on our observations and previous findings
by other researchers, a hypothesis for the differential accumulation and identical translocation patterns of the two Cr ions
is proposed.
Received: 27 February 1998 / Accepted: 2 April 1998 相似文献
19.
Rapid Effects of Abscisic Acid on Ion Uptake in Sunflower Roots 总被引:1,自引:0,他引:1
Short-term effects of ABA, ABA + kinetin and kinetin on ion (86Rb-potassium and phosphate) and water uptake in sunflower plants (Helianthus annuus var. californicus) were examined with a continuous-recording technique. Ion uptake in the roots and transport to the shoots were also investigated by conventional tracer uptake experiments and by sap bleeding experiments with excised roots. After addition of 5 × 10?6-4 × 10?5M ABA to the root medium there was an immediate decrease (30–70%) in the rate of ion uptake which lasted 30–70 min. The rate of water uptake was not significantly affected as measured with this method. Ion transport to the shoots and to the bleeding sap of excised roots was decreased by ABA. ABA-induced inhibition of ion uptake was abolished by the presence of kinetin, and uptake was slightly stimulated by 2 × 10?5M kinetin alone. We suggest that concentration gradients of ABA or rapid changes in the ABA-kinetin balance in the roots affect ion uptake and transport. 相似文献
20.
Regulation by ABA of osmotic-stress-induced changes in protein synthesis in tomato roots 总被引:2,自引:0,他引:2
Polypeptide synthesis and accumulation were examined in the roots of tomato seedlings exposed to a polyethylene glycol‐imposed water deficit stress. In these roots, the synthesis of a number of polypeptides was induced, while that of several others was enhanced or repressed. To examine the role played by abscisic acid (ABA) in co‐ordinating the accumulation of these proteins, water‐deficit‐stress‐responsive polypeptide synthesis was investigated in the roots of the ABA‐deficient mutant flacca. In the roots of this mutant, the ability to accumulate a complete set of water‐deficit‐stress‐responsive polypeptides was impaired, indicating that ABA is required for their synthesis. The role of ABA was further examined by exposing the roots of both genotypes to exogenous ABA, which, with one exception, elicited the accumulation of all water‐deficit‐stress‐responsive proteins. Polyethylene glycol‐induced polypeptide accumulation was accompanied by a 1·6‐fold increase in the level of endogenous ABA in the roots of wild‐type plants and a 5‐fold increase in the roots of flc. Thus, although the absolute level was lower than that of the wild‐type, flc has the capacity to accumulate ABA in its roots. When fluridone was used to prevent the biosynthesis of ABA, the accumulation of several water‐deficit‐stress‐responsive polypeptides was reduced further. The synthesis of polypeptides was also examined in the roots of salt‐treated seedlings. Salt altered the accumulation of several polypeptides, all of which were previously observed in water‐deficit‐stressed roots, indicating that their synthesis was the result of the osmotic component of the salt stress. However, the accumulation of these polypeptides was not impaired in flc roots, indicating that the role played by ABA in regulating their accumulation in salt‐and polyethylene glycol‐treated roots differs. As such, salt‐ and water‐deficit‐stress‐induced changes in gene expression may be effected by different mechanisms, at least at the level of polypeptide accumulation. 相似文献