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1.
Bożena Pawlikowska-Pawlěga Kazimierz Trěbacz Elżbieta Król Antoni Gawron 《Acta Physiologiae Plantarum》2000,22(1):61-67
Quercetin is a very common flavonoid widely distributed in many plants. The flavonoid intake has been linked to the prevention
of human diseases including cancer. Flavonoids possess also a broad spectrum of effects on plants. Quercetin is involved in
Ca2+ transport and metabolism. The present study was designed to check the effects of quercetin alone and in combination with
verapamil on the resting and action potentials in the liverwort Conocephalum conicum. The application of 59·10−6 mol·dm−3 quercetin caused an increase of action potential amplitudes. During the 3rd and 4th hour of treatment an increase by 20–22
% with respect to the control was observed. No changes were found in the resting potential in quercetin treated plants. Verapamil,
a calcium channel inhibitor, caused gradual decrease of action potential amplitudes. Quercetin, when added together with verapamil,
prevented its inhibitory effect. Interactions between quercetin and Ca2+ transport are discussed. 相似文献
2.
Bożena Pawlikowska-Pawlęga Elżbieta Król Kazimierz Trębacz Antoni Gawron 《Acta Physiologiae Plantarum》2011,33(4):1335-1344
Apigenin, quercetin and genistein are members of the family of plant flavonoids suspected to prevent a number of human diseases,
for instance cancer development. They display a number of activities, and part of their beneficial effects may be due to their
affinity to cellular membranes. In this study, we used Conocephalum conicum, a well-elaborated model of liverworts. Intracellular microelectrode measurements were carried out to examine the effects
of flavonoids in combination with neomycin on the resting and action potentials. Neomycin triggered gradual decline of action
potential amplitudes through a membrane potential decrease (membrane potential became less negative) and a decrease of the
action potential peak value. Additionally, duration of action potential amplitudes measured at half of the amplitude increased
in neomycin-treated plants. However, the simultaneous use of quercetin or genistein (but not apigenin) with neomycin hindered
neomycin-specific actions. Hence, the membrane resting potential and action potential amplitudes regained neomycin-free values.
It may be concluded that application of at least some flavonoids (namely quercetin and genistein) exerts strong influence
on electrical membrane responses in C. conicum. 相似文献
3.
The effect of three different anion channel inhibitors, namely(5-nitro-2-3-phenylpropyl-amino)benzoic acid (NPPB), Zn2+ andanthracene-9-carboxylic acid (A-9-C) on the action potentialin the liverwort Conocephalum conicum were tested. All threecaused an increase of the excitability threshold and a decreaseof action potential amplitudes. This confirms the involvementof anion channels in the action potentials in Conocephalum.In plants treated with 1 or 2 mM A-9-C but not with NPPB (50or 100 µM) and Zn2+ (100 or 500 µM), a light-inducedtransient depolarization occurred. In contrast to action potentials,the amplitude of this voltage transient depended on the lightintensity and on the duration of preceding dark period. Alsoin contrast to action potentials, which are blocked by TEA,when applied together with A-9-C, TEA even increased the amplitudesof the light-induced voltage transients to up to 170 mV. Thedepolarization was obviously limited by the voltage-dependentopening of K+ channels in the absence of TEA. The amplitudeof the light-induced voltage transients (in the presence ofTEA) increased in elevated CaCl2 concentrations pointing toa Ca2+ permeability giving rise to the depolarization. However,none of the Ca2+ channel blockers tested, La3+, Gd3+, nifedipine,verapamil or diltiazem, had an effect. The light-induced voltagetransients in A-9-C treated plants are quite different fromlight- and electrically triggered action potentials but sharesome similarities with light-induced generator potentials. (Received July 9, 1996; Accepted February 20, 1997) 相似文献
4.
Secondary plant metabolites undergo several modification reactions, including glycosylation. Glycosylation, which is mediated by UDP-glycosyltransferase (UGT), plays a role in the storage of secondary metabolites and in defending plants against stress. In this study, we cloned one of the glycosyltransferases from rice, RUGT-5 resulting in 40–42% sequence homology with UGTs from other plants. RUGT-5 was functionally expressed as a glutathione S-transferase fusion protein in Escherichia coli and was then purified. Eight different flavonoids were used as tentative substrates. HPLC profiling of reaction products displayed at least two peaks. Glycosylation positions were located at the hydroxyl groups at C-3, C-7 or C-4′ flavonoid positions. The most efficient substrate was kaempferol, followed by apigenin, genistein and luteolin, in that order. According to in vitro results and the composition of rice flavonoids the in vivo substrate of RUGT-5 was predicted to be kaempferol or apigenin. To our knowledge, this is the first time that the function of a rice UGT has been characterized. 相似文献
5.
To investigate the biocontrol effectiveness of the antibiotic producing bacterium, Pseudomonas aureofaciens 63–28 against the phytopathogen Rhizoctonia solani AG-4 on Petri plates and in soybean roots, growth response and induction of PR-proteins were estimated after inoculation
with P. aureofaciens 63–28 (P), with R. solani AG-4 (R), or with P. aureofaciens 63–28 + R. solani AG-4 (P + R). P. aureofaciens 63–28 showed strong antifungal activity against R. solani AG-4 pathogens in Petri plates. Treatment with P. aureofaciens 63–28 alone increased the emergence rate, shoot fresh weight, shoot dry weight and root fresh weight at 7 days after inoculation,
when compared to R. solani AG-4; P + R treatment showed similar effects. Peroxidase (POD) and β-1,3-glucanase activity of P. aureofaciens 63–28 treated roots increased by 41.1 and 49.9%, respectively, compared to control roots. POD was 26% greater in P + R treated
roots than R. solani treated roots. Two POD isozymes (59 and 27 kDa) were strongly induced in P + R treated roots. The apparent molecular weight
of chitinase from treated roots, as determined through SDS-PAGE separation and comparison with standards, was about 29 kDa.
Five β-1,3-glucanase isozymes (80, 70, 50, 46 and 19 kDa) were observed in all treatments. These results suggest that inoculation
of soybean plants with P. aureofaciens 63–28 elevates plant growth inhibition by R. solani AG-4 and activates PR-proteins, potentially through induction of systemic resistance mechanisms. 相似文献
6.
G. A. Prudnikov L. A. Panichkin M. S. Krasavina 《Russian Journal of Plant Physiology》2010,57(6):865-874
Electric potential difference was measured with extracellular electrodes between the leaf surface of 2-week-old cucumber (Cucumis sativus L.) plants and soil solution. When the leaf region with a diameter of 5 mm was gradually cooled during a 105-s period to
8–9°C, the temperature drop induced a local (confined to the cooled area) nonpropagating pulse-wise electric activity. The
cessation of cooling was followed by gradual (within 12–15 min) restoration of the initial potential difference. Two peaks
of electric potential with amplitudes of 100–120 mV usually appeared upon cooling. The first depolarizing stage of the pulse
activity was sensitive to inhibition of voltage-gated and mechanosensitive calcium channels of plasmalemma by lanthanum and
gadolinium chlorides and to verapamil treatment. Furthermore, the inhibition of this stage by ruthenium red implies the release
of calcium ions from intracellular stores. The initial slow depolarization was followed by a fast depolarizing shift, which
was sensitive to La3+ and the anion channel inhibitor 4-acetamido-4′-isothiocyano-stilbene-2,2′-dilsulfonic acid. At the next stage repolarization
developed, which was sensitive to potassium channel blockers, tetraethylammonium and quinine sulfate. The influence of ion
channels blockers indicates that generation of local bioelectric response is based on fluxes of the same ion species that
are involved in the action potential. The depolarization stage was due to the transient Ca2+ influx into the cytosol from the apoplast and intracellular stores, together with the anion efflux from the cell; the repolarization
stage involved potassium ions. Both stages of electric pulse generation were retarded by the H+-ATPase inhibitors, sodium orthovanadate and dicyclohexylcarbodiimide, which implies the involvement of the proton pump in
the origin of electric pulses examined. 相似文献
7.
Using the whole-cell voltage-clamp technique, the effects of the neuropeptide Phe-Met-Arg-Phe-NH2 (FMRFa) on two types of dihydropyridine-sensitive, high-voltage-activated calcium currents were investigated in isolated
neuroendocrine caudo-dorsal cells (CDCs), which control egg-laying in the molluscLymnaea stagnalis. These currents are: (1) a transient current (Τinact = ∼10–25 ms) with an activation threshold of −40 mV and maximal amplitude at +10 mV and (2) a sustained current (Τinact = ∼ 100–300 ms) with a threshold of −10 mV and apeak at +30 mV.
FMRFa caused a partial block of the calcium current that was rapid, reversible and dose-dependent (ED50 = 4.3 nM). The FMRFa-sensitive and insensitive currents differed in voltage-dependence of activation and inactivation, steady-state
inactivation characteristics and time course of recovery from inactivation, all indicating that FMRFa selectively suppressed
the sustained calcium current.
Internal perfusion of CDCs with GTP-γ-S or GDP-Β-S depressed the FMRFa response, suggesting the involvement of G-proteins.
Experiments aimed at elucidation of the signal transduction pathway between the FMRFa receptor and the calcium channel revealed
no involvement of second messengers and protein kinases. The FMRFa-induced inhibition of the sustained calcium current probably
results from a direct interaction between a G-protein, activated by the FMRFa receptor, and the calcium channel.
The selective inhibition of this calcium current is likely to decrease the influx of calcium during the action potential,
which will reduce the release of autoexcitatory CDC-peptides and contribute to a suppression of excitability. 相似文献
8.
Soil-to-plant abiotic transport of a recombinant nucleopolyhedrovirus (HzSNPV.LqhIT2) was studied to quantify the proportion
of different concentrations of soil virus transported to specific parts of cotton plants under controlled greenhouse conditions;
these results were related to transport in the field where wind, rain, and soil type were not controlled. Under conducive
precipitation conditions in the greenhouse, the estimated number of viral occlusion bodies (OB) transported ranged from 7 OB
(to the top third of the plant, 40–60 cm above the soil, at the low virus concentration, 250 OB/g soil) to 629 OB (to the
bottom third of the plant, 0–20 cm, at the high virus concentration, 12,500 OB/g soil). Under conducive wind conditions in
the greenhouse, the estimated number of OB transported ranged from 8 OB (to the top third of the plant at the low concentration)
to 94 OB (to the bottom third of the plant at the high concentration). The overall proportion of OB transported from soil
to plant was greatest, ranging from 2.1–6.2 × 10−6, from the lowest soil concentration to the lowest 40 cm of the plant. Only 5 × 10−8 of the soil OB were transported from the high-concentration soil to a height of 40–60 cm on the plants. In the field experiment,
the estimated number of OB on each cotton plant depended on the concentration of OB in soil in June and July, but this effect
was no longer significant in August. There were significantly more OB on the lower third of plants than on the top third in
July, but not in June or August. Significantly more OB were detected on cotton leaves than on buds or squares in July, and
there were more OB on leaves than on buds, squares, bracts, or bolls in August. The amount of HzSNPV.LqhIT2 naturally transported
from soil to cotton plants was sufficient to infect 6–11% (low to high soil concentration) of first instar Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) in June, 2–6% in July, and 1–3% in August. These results fill gaps in understanding
NPV epizootiology that are important to biological control and risk assessment. 相似文献
9.
Oscillations with a period of 1–2 min in the rate of photosynthesis have been found in leaves of C3 and C4 land plants under invariant, saturating, light and carbon dioxide. This article reports the occurrence of similar oscillations
with a period of 2–2.5 min in individual cells of the marine diatom Coscinodiscus wailesii. These oscillations were determined by measurements of both oxygen (oxygen microelectrode) and carbon dioxide (pH microelectrode)
just outside the plasmalemma. These oscillations were found in less than 1% of the cells examined. The occurrence of oscillations
in unicelluar diatoms rules out for these organisms hypotheses as to the origin of oscillations in land plant leaves that
are based on cell–cell interactions. 相似文献
10.
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
11.
The effect of low doses of UV-A (320–400 nm) and UV-B (280–320 nm) radiation on photosynthetic activities inPhaseolus mungo L. was investigated under field condition. Supplementation of UV-A enhanced the synthesis of chlorophyll and carotenoids
than the UV-B supplemented plants. Significant increase was seen in the concentration of UV-B absorbing compounds of UV-B
treated plants. Increase of PS 2 activity in UV-A treated plants was seen. Changes in photosynthetic activity were measured
in terms of PS 2 mediated O2 evolution and Chl a fluorescence. 相似文献
12.
We examined the effects of genetic transformation by Agrobacterium rhizogenes on the production of tylophorine, a phenanthroindolizidine alkaloid, in the Indian medicinal plant, Tylophora indica. Transformed roots induced by the bacterium grew in axenic culture and produced shoots or embryogenic calli in the absence of hormone treatments. However, hormonal treatment was required to regenerate shoots in root explants of wild type control plants. Transformed plants showed morphological features typically seen in transgenic plants produced by A. rhizogenes, which include, short internodes, small and wrinkled leaves, more branches and numerous plagiotropic roots. Plants regenerated from transformed roots showed increased biomass accumulation (350–510% in the roots and 200–320% in the whole plants) and augmented tylophorine content (20–60%) in the shoots, resulting in a 160–280% increase in tylophorine production in different clones grown in vitro. 相似文献
13.
Hemant Pandey Shyamal K. Nandi Anil Kumar Uma T. Palni Lok Man S. Palni 《Acta Physiologiae Plantarum》2007,29(2):121-126
Podophyllum hexandrum Royle, an important alpine herb, and a source of the highly valued aryltetralin-type lignan, podophyllotoxin, has been subjected
to heavy collection from the wild due to ever increasing demand. The present study deals with an attempt to bring this plant
under cultivation at a relatively lower altitude and to evaluate (1) various growth parameters including above and below ground
biomass accumulation, net assimilation rate and relative growth rate, etc., and (2) podophyllotoxin content from the resulting
above and below ground biomass in seed raised plants of a known age series of 1–5 years. The podophyllotoxin content was estimated
on the basis of HPLC analyses. The levels were found to increase with the plant age and the maximum amount was found in 5-year
old plants. This study demonstrates that (1) seeds can be conveniently used for raising healthy propagules in easily approachable
locations at a relatively lower altitude, and that the plants can be maintained in such sites over long periods, and (2) this
approach of “conservation through cultivation” can be suggested as an effective tool for the management of this “critically
endangered status” species. 相似文献
14.
S. Kumar Sunil Kumar S. P. Negi J. K. Kanwar 《In vitro cellular & developmental biology. Plant》2008,44(6):474-479
Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium
containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About
30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable
resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates. 相似文献
15.
Summary We describe an in vitro propagation protocol for Zingiber petiolatum (Holttum), I. Theilade, a rare species from the southern part of Thailand. Fruits were surface-sterilized and seeds germinated
on Murashige and Skoog medium (MS) medium supplemented with 3% sucrose. Three-month-old seedlings were used as initial plant
material for in vitro propagation. Terminal buds of the plants were inoculated on MS medium containing 6-benzylaminopurine (BA; 2.2–35.5 μM) alone or in combination with 1-naphthaleneacetic acid (0.5 μM). Eight weeks after inoculation, the cultures were transferred to MS medium without plant growth regulators for 4wk. The
cultures transferred from MS medium with 17.8 μM BA revealed the highest shoot induction rate of 6.1±0.7 shoots per explant. Rooting was spontaneously achieved in MS medium
without plant growth regulators. Rooted plants were successfully transplanted to soil. 相似文献
16.
Ethylene influences green plant regeneration from barley callus 总被引:3,自引:0,他引:3
The plant hormone ethylene is involved in numerous plant processes including in vitro growth and regeneration. Manipulating
ethylene in vitro may be useful for increasing plant regeneration from cultured cells. As part of ongoing efforts to improve
plant regeneration from barley (Hordeum vulgare L.), we investigated ethylene emanation using our improved system and investigated methods of manipulating ethylene to increase
regeneration. In vitro assays of regeneration from six cultivars, involving 10 weeks of callus initiation and proliferation
followed by 8 weeks of plant regeneration, showed a correlation between regeneration and ethylene production: ethylene production
was highest from ‘Golden Promise’, the best regenerator, and lowest from ‘Morex’ and ‘DH-20’, the poorest regenerators. Increasing
ethylene production by addition of 1-aminocyclopropane 1-carboxylic acid (ACC) during weeks 8–10 increased regeneration from
Morex. In contrast, adding ACC to Golden Promise cultures during any of the tissue culture steps reduced regeneration, suggesting
that Golden Promise may produce more ethylene than needed for maximum regeneration rates. Blocking ethylene action with silver
nitrate during weeks 5–10 almost doubled the regeneration from Morex and increased the Golden Promise regeneration 1.5-fold.
Silver nitrate treatment of Golden Promise cultures during weeks 8–14 more than doubled the green plant regeneration. These
results indicate that differential ethylene production is related to regeneration in the improved barley tissue culture system.
Specific manipulations of ethylene were identified that can be used to increase the green plant regeneration from barley cultivars.
The timing of ethylene action appears to be critical for maximum regeneration. 相似文献
17.
Summary This study reports a protocol for successful micropropagation of Decalepis arayalpathra (Joseph and Chandras) Venter. (Janakia arayalpathra Joseph and Chandrasekhran; Periplocaceae), a critically endangered and endemic ethnomedicinal plant in the southern forests of the Western Ghats which is overexploited
for its tuberous medicinal roots by the local Kani tribes. Natural regeneration is rare and conventional propagation is difficult.
Conservation of the species through micropropagation was attempted. The nodal explants of greenhouse-raised plants, were more
desirable than cotyledonary nodal explants of aseptic seedlings. The basal nodes (73%) of 12–16-wk-old greenhouse-grown plants
cultured in Murashige and Skoog (MS) medium containing 12.96 μM 6-benzyladenine (BA), 2.48 μM 2-isopentenyladenine (2-ip) and 2.68 μM α-naphthaleneacetic acid (NAA) formed 16–17 cm long unbranched robust solitary shoots in 8 wk. Cotyledonary nodal explants
cultured in the same medium showed multiple shoot formation and axillary branching. But the shoots were thin, fragile and
not suitable for mass propagation. Single nodes of a solitary shoot subcultured on MS medium containing 2.22 μM BA and 0.24 μM 2-ip together produced 9.8±0.3 nodes from 18.0±0.6 cm long shoots within 5–6 wk. The basal nodes of the shoots so formed
were repeatedly subcultured to increase the stock of propagules while the 2.5–3.0 cm terminal cuttings were used for rooting.
The best root induction (68%) and survival (86%) was achieved on half-strength MS medium supplemented with 1.07 μM NAA. Field-established plants showed uniform growth and phenotypic similarity to parental stock. 相似文献
18.
An efficient micropropagation system for Erigeron breviscapus (vant.) Hand. Mazz., an important medicinal plant for heart disease, has been developed. Shoot organogenesis occurred from
E. breviscapus leaf explants inoculated on a medium supplemented with a combination of plant growth regulators. On average, 17 shoots per
leaf explant were produced after 30 days when they were cultured on MS basal salts and vitamin medium containing 5 μM 6-benzylaminopurine
(BAP) and 5 μM 1-naphthaleneacetic acid (NAA). All the regenerated shoots formed complete plantlets on a medium containing
2.5–10 μM indole-3-butyric acid (IBA) within 30 days, and 80.2% of the regenerated plantlets survived and grew vigorously
in field conditions. Based on the variation in common peaks and the produced amount of the most important bioactive component,
scutellarin, a high performance liquid chromatography (HPLC) fingerprinting system was developed for quality control of these
micropropagated plants. Chemical constituents in E. breviscapus micropropagated plants varied during plant development from regeneration to maturation, the latter of which showed the most
similar phytochemical profile in comparison with mother plants. The regeneration protocol and HPLC fingerprint analysis developed
here provided a new approach to quality control of micropropagated plants producing secondary metabolites with significant
implications for germplasm conservation. 相似文献
19.
Hye Jin Choi Thummala Chandrasekhar Hyo-Yeon Lee Kyung-Moon Kim 《Plant Cell, Tissue and Organ Culture》2007,91(3):235-242
Transgenic herbicide-resistant sweet potato plants [Ipomoea batatas (L.) Lam.] were produced through Agrobacterium-mediated transformation system. Embryogenic calli derived from shoot apical meristems were infected with Agrobacterium tumefaciens strain EHA105 harboring the pCAMBIA3301 vector containing the bar gene encoding phosphinothricin N-acetyltransferase (PAT) and the gusA gene encoding β-glucuronidase (GUS). The PPT-resistant calli and plants were selected with 5 and 2.5 mg l−1 PPT, respectively. Soil-grown plants were obtained 28–36 weeks after Agrobacterium-mediated transformation. Genetic transformation of the regenerated plants growing under selection was demonstrated by PCR,
and Southern blot analysis revealed that one to three copies of the transgene were integrated into the plant genome of each
transgenic plant. Expression of the bar gene in transgenic plants was confirmed by RT-PCR and application of herbicide. Transgenic plants sprayed with Basta containing
900 mg l−1 of glufosinate ammonium remained green and healthy. The transformation frequency was 2.8% determined by herbicide application
which was high when compared to our previous biolistic method. In addition, possible problems with multiple copies of transgene
were also discussed. We therefore report here a successful and reliable Agrobacterium-mediated transformation of the bar gene conferring herbicide-resistance and this method may be useful for routine transformation and has the potential to develop
new varieties of sweet potato with several important genes for value-added traits such as enhanced tolerance to the herbicide
Basta. 相似文献
20.
The effects of UV-B radiation (290–320 nm) on development of damping-off of spinach (Spinacia oleracea) caused by the fungusFusarium oxysporum were examined in a growth cabinet. The incidence of disease greatly increased when experimental plants were grown in visible
radiation with supplementary UV-B radiation. This increase was suppressed by increasing the irradiation of visible radiation.Fusarium oxysporum was isolated from the roots of all damping-off plants and the roots of some unwilted plants, indicating that spinach infected
with the pathogen did not necessarily suffer from damping-off in 15d. Supplementary UV-B radiation suppressed the increase
in growth components such as the number of leaves, the plant height and the fresh weight of aboveground plant parts, but did
not affect the fresh weight of roots. The ratio of the number of plants infected with pathogen to the total number of plants
was over 80% irrespective of light conditions. It was suggested that the defense response of spinach to this pathogen was
greatly influenced by the physiological state of aboveground plant parts resulting from supplementary UV-B radiation. 相似文献