摘要:

Lupin (Lupinus luteusL. cv. Weiko III) were grown in nutrient solution over a range of inorganic phosphate (Pi) concentrations, with or without 50 mMNaCl. Plants with high Pi(2 mM) and salt showed progressive leaf necrosis and had higher concentrations of total phosphate than plants grown with high Pialone. Most of the extra total phosphate in salt treated plants was in the Piform. Pisupply did not influence Na+, K+or Cl−concentrations in epidermal vacuoles or mesophyll cells. However, epidermal vacuoles accumulated more monovalent cations (Na+and K+) than Cl−, and in vacuoles of plants grown with 0.1 mMPiadditional Piwas accumulated, possibly to maintain charge balance. Plants grown with 2 mMPidid not accumulate additional Piin epidermal vacuoles, but showed higher phosphorus levels in cell walls. It is suggested that at moderate phosphorus concentrations Piplays a role in epidermal osmotic adjustment, possibly explaining the beneficial role of additional phosphorus on salt stressed plants. At high Pisupply with salt, Pidoes not contribute to osmotic adjustment and instead accumulates in cell walls. However, the cause of leaf damage under conditions of high phosphorus supply and salinity is still not entirely cl

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00604.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Plants of annual celery (Apium graveolensL.) were treated with paclobutrazol during anthesis. Seeds collected from the treated plants showed a marked reduction in germination in light and failed to germinate in the dark. Application of GA4/7to the imbibition solution reversed the inhibitory effect of paclobutrazol while gibberellic acid (GA3) was ineffective. Benzyladenine (BA) interaction with GA4/7was light and concentration‐dependent. At relatively low concentrations in the dark there was a synergistic effect, but at higher concentrations, especially in the light, BA, antagonized the GA4/7effect. Seedlings emerging from the seeds from paclobutrazol‐treated plants were only slightly shortened. It is suggested that paclobutrazol applied to the mother plants inhibited the biosynthesis of endogenous GAs, which normally enable the germination of annual seeds under unfavorable conditions. Exogenously applied GA4/7fulfills the function of the absent endogenous

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00605.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Infected and uninfected cell protoplasts were isolated from soybean (Glycine maxL. Merr. cv. Akisengoku) root nodules and purified by the use of nylon mesh filters and discontinuous Percoll gradients. Activities of the enzymes involved in carbon and nitrogen metabolism were measured in cytoplasmic fractions of purified protoplasts, as well as in the bacteroids isolated from infected cell protoplasts and in the cortical tissues after enzymatic digestion of the central zone of the nodules.A high degree of purity of both infected and uninfected cells was demonstrated by microscopic observations and assays of β‐hydroxybutyrate dehydrogenase (EC 1.1.1.30) and uricase (EC 1.7.3.3) activities and leghemoglobin contents.As a whole, higher specific activities of enzymes of glycolysis were found in the cortical and uninfected cells than in the infected cells. The activities of glycolytic enzymes were extremely low in the bacteroids. Invertase (EC 3.2.1.26) was highly localized in the cortex. However, activity of sucrose synthase (EC 2.4.1.13) was highest in the cytosol of infected cells. Alcohol dehydrogenase (EC 1.1.1.1) and lactate dehydrogenase (EC 1.1.1.27) activities were much higher in uninfected than in infected cells. Specific activities of enzymes for nitrogen assimilation, that is, glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 1.4.1.14), aspartate (EC 2.6.1.1) and alanine (EC 2.6.1.2) aminotransferase were several‐fold higher in uninfected cells than in the infected cells.The results are discussed in relation to the possible cellular organization of carbon and nitrogen metabolism in soybean root nod

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00606.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

In the subarctic mossDicranum elongatumSchleich&Schwaegr., the level of total lipids and triacylglycerols (TAG) was high in late winter and spring and low in autumn and winter. Four‐week exposure of field material to continuous light (135μmol m−2s−1) at 1°C resulted in a considerable increase in the amount of TAG in the autumn material acclimated to low temperatures and rhythmic light in the field. In contrast, the same treatment did not cause any increase in TAG in the spring material, acclimated to low temperatures and continuous light in the field. Results from experiments, in which moss cultivated for 4 months at 9°C on 12‐h photoperiods (135μmol m−2s−1) was kept for 3 weeks at low temperatures (9°C and −3°C) either in continuous light (135 or 70 μmol m−2s−1) or with 12‐h photoperiods (135 μmol m−2s−1), indicated that the TAG level was higher at higher light intensity. At 9°C it was also higher in continuous light of both intensities than in rhythmic light. These results strongly suggest that decreasing irradiance and decreasing daylength limits the accumulation of TAG inD. elongat

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00607.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The plasma membrane of eukaryotic cells contains endogenous, integral electron transport proteins. In the maize (Zea maysL. cv. Golden Cross Bantam) root plasma membrane, these activities include NAD(P)H‐ferricyanide reductase. NAD(P)H‐duroquinone reductase (1.6.5.1) and NAD(P)H‐ascorbate free‐radical reductase (EC 1.6.5.4). Differences in degree of stimulation upon vesicle rupture with detergent and in specificities for pyridine nucleotides suggest that these activities constitute distinct components in the membranes. Solubilization of reductase activities was examined using Triton X‐100 over a wide range of retergent‐to‐protein ratios. The Triton‐solubilized enzymes were purified using dye‐ligand affinity chromatography on Cibacron blue 3G‐A agarose utilizing biospecific elution with NADH. Resolution of the redox activities was accomplished upon differential elution with 0.1.1.0 and 10 mMNADH. The distinctive characteristics of the enzymes and the differential chromatographic behavior of the respective activities provided evidence for the presence of separate enzymatic redox components in maize root plasma membranes with implications for an elec

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00608.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

GA1, GA8, GA17, GA19, GA20and GA29were identified by combined gas chromatography‐mass spectrometgry (GC‐MS) in immature seeds and pericarp ofLycopersicon esculentumMill. (tomato). Higher levels of these GAs were present in the seeds than in the pericarp; seeds in addition contained GA15, GA24, GA25, and GA44. Fruits of theLycopersicon pimpinellifoliumMill. mutant I were smaller and contained lower GA1concentrations, but higher GA20concentrations, than those of mutants III and IV. In contrast, differences in fruit size inL. esculentumdue to position on the truss did not correlate with GA1concentration in either the pericarp or se

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00609.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Treatment with Ca2+channel blockers such as lanthanum chloride and verapamil promoted abscission in pulvinar explants of bean (Phaseolus vulgarisL. ev. Pirate). In addition, auxin‐induced delay of abscission was markedly reduced in the presence of Ca2+channel blockers. In vitro phosphorylation studies were performed using membrane preparations (130000gpellet) from freshly excised as well as auxintreated and control (minus auxin) pulvinar sections. Auxin‐treated sections showed a 66 kDa phosphoprotein as well as Ca2+‐dependent phosphorylation that were not observed in control explants.Coomassie blue stammg of soluble proteins (130000 g supernatent) separated on SDS‐PAGE revealed the presence of 62. 55 and 47 kDa polypeptides only in the freshly excised pulvini. However. no distinct changes were observed in soluble protein profile between auxin‐treated and control explants. When soluble proteins were phosphorylated in vitro, Ca2+promoted the phosphorylation of 92, 55. 40 and I7 kDa polypeptides only in freshly excised pulvmi. Ca2+‐dependent phosphorylation of soluble proteins was not observed in either the control or auxin‐treated explants. In addition. in vivo phosphorylation studies were performed using freshly excised. auxrn‐treated and control explants. Freshly excused segments and auxin‐treated ex‐plants showed similar phosphoproteins, which were different from thos

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00610.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

In vitro responses can be influenced by the developmental status of the donor plant tissue. The effects of the donor plant photoperiod and the developmental stage of the plant on organogenesis of petiole explants ofBegonia×hiemaliscv. Schwabenland Pink are reported. Long day plants had progressively more branches, total stem length, leaf area, and branch and shoot mass. In short days, flowering was earlier and a greater proportion of dry weight accumulation was allocated to reproductive structures. Similar explant responses were obtained from all developmental stages until flowering was well advanced in short days and then the regenerative capacity diminished. Primary measurements of donor leaves (length, area and weight) at the time of explant removal were not well correlated with adventitious bud production. Loss of regeneration was not determined by tissue or plant age but was associated with the progressive development of flowers. Thus the donor plant photoperiod only indirectly affected bud production. Organogenesis decreased with duration of short days but increased in long days and thus both the duration of the multiplication phase and the intensity of the in vitro response was enhanced by maintaining donor plants in long days

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00611.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

High temperature (45°C) inhibits seed germinition and seedling sunflower (Helianthus annuusL. cv. Mirasol). Treatment of imbibed seeds at 45°C for more than 48 h induces a secondary dormancy, which is associated with progressive decrease of germination ability at optimal temperature (25°C) as well as with abnormal seedling growth. Ethylene (55μl l−1) and 2‐chloroethylphosphonic acid (ethephon) (2.5 mM) improve germination of thermodormant seeds at 25°C. but the abnormal growth of the seedlings remains. O2‐enriched atmosphere and dry storage improve germination and normal seedling growth. The induction of thermodormancy in sunflower seeds seems associated with loss of their ability to convert 1‐aminocyclopropane‐1‐carboxylic acid (ACC) to ethylene. Possible effects of high temperature on membranes and ethylene forming enzyme (EF

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00612.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The effect of O2concentration on energy metabolism and senescence has been studied in cut flowers ofDianthus caryophyllusL. cv. Scania. As compared to the control (21% O2), 5% O2delays flower senescence as well as decay of nucleotide level and AEC (adenylate energy charge). An atmosphere of 100% O2accelerates senescence as well as the decrease of nucleotide level and AEC. While anoxia brings about a faster decrease of ATP and AEC than of total nucleotides, hyperoxia brings about a faster decrease in adenyl nucleotides than in ATP and AEC values. Petal oxygen uptake is over 90% of the maximal value under 4% O2and saturates at 10% O2. The development of senescence is dicussed as a two phase process (first phase‐progressive and second phase‐catastrophic) triggered by the action of hyperoxia, first on the system for energy utilization and later on the system for energy production, the degradation of which seems to be linked with increase in membrane permeability and wither

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1988.tb00613.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY