摘要:

Three‐week‐old shoots of the spring oilseed rape cv. Petranova (Brassica napusL. ssp.napus) were found by combined gas chromatography‐mass spectrometry to contain GA1, GA8, GA15, GA17, GA19, GA20, GA24, GA29, 3‐epi‐GA1and a previously uncharacterised C19dicarboxylic acid that is probably structurally related to GA24. Shoots of the winter cultivar Belinda, harvested at the early flowering stage, contained the same GAs with the exception of the C19dicarboxylic acid and, in addition, GA34and GA51were identified. All material contained higher levels of GA20than of GA1; the ratio of GA1to GA20was highest in shoots containing the largest proportion of young immature tissues. Soil treatment of cv. Petranova seedlings with the growth retardant BAS 111¨W [1‐phenoxy‐5,5‐dimethyl‐3‐(1,2,4‐triazol‐1‐yl)‐hexan‐4‐ol] caused 80% reduction in height 18 days after treatment and the levels of all GAs were 20% or less that of control plants. Foliar treatment at the same dosage reduced height by 50% and caused an 85% or greater reduction in the concentrations of the GA1precursors GA20, GA19and GA44. However, the levels of GA1, GA8and GA29were affected to a much smaller extent. Foliar application of BAS 111¨W to cv. Belinda 1 month after sowing resulted in only a 20% height reduction at flowering, but no uniform decrease in the concentration

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05607.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Polyclonal antibodies, raised against ((1→3), (1→4)‐β‐D‐glucans from oat (Avena sativaL.) caryopsis, were used to investigate the location and the metabolism of mixed‐linked β‐D‐glucans. The binding of these antibodies to the cell walls of oat coleoptiles was shown by an indirect fluorescence method. Distinct fluorescent regions were observed along the inner layers of the walls of each cell. The preimmune serum or antibodies pretreated with oat caryopsis β‐D‐glucans did not react with the cell walls. Glucan antibodies were bound to the walls of other Poaceae coleoptiles as well as to those from oat mesocotyls and roots, whereas they were not bound to the walls of some dicotyledons tested. The relative glucan content of the cell walls of oat coleoptiles as determined by β‐D‐glucanase (EC 3.2.1.73) treatment was maximum between day 3 and 4 after soaking, but it declined during further elongation. A rapid decrease in glucan content was observed in excised coleoptiles when auxin or β‐D‐glucanase was present. There was a clear correlation between the glucan content expressed on a basis of cell wall polysaccharides and the amount of the antibodies bound to the cell walls. These results indicate that the antibodies are useful probes to detect and determine (1→3

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05608.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The protein extracted from the cell wall of the epicotyls ofCicer arietinumL. cv. Castellana was separated by ion exchange chromatography in four different fractions with β‐D‐galactosidase (EC 3.2.1.23) activity. These were called βI, βII, βIII and βIV, according to their order of elution. βII was associated with a particularly high β‐D‐glucosidase (EC 3.2.1.21) activity. Gel filtration chromatography of each of the fractions gave further subdivision of fractions βI and βIII. Subfractions 1 βI, 1 βII and 1 βIV have glucosidase activity and subfractions 2 βI and 2 βIII have galactosidase activity.The studies on the hydrolytic capacity of these fractions and its relationship with the autolytic process seem to show that subfraction 2 βIII is responsible for autolysis. The release of total and reducing sugars is very similar for autolysis and hydrolysis by 2 βIII. The sugars released are mainly galactose and, to a lesser extent arabinose and glucose. Galactose is released as a monosaccharide, while arabinose remains associated to a polysaccharide component together with glucose and sma

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05609.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Two protein fractions with activity as α‐galactosidase (EC 3.2.1.22) and α‐arabinosidase (EC 3.2.1.55), respectively, were identified in the proteins of cell wall ofCicer arietinumL. cv. Castellana extracted with 3MLiCl. These fractions were partially purified by gel filtration chromatography (Bio Gel P‐150), increasing the specific arabinosidase activity 57‐fold and the α‐galactosidase activity 6‐fold. Other protein fractions with glucosidase (EC 3.2.1.21) and glucanase (EC 3.2.1.6) activity also appeared. According to earlier authors, α‐arabinosidases and α‐galactosidases are related to alterations in linkages occurring in cell walls, since the enzymes are able to hydrolyze isolated wall polymers. However, our preparations hydrolyze intact cell walls only to a very limited extent, such that their participation in the autolytic processes of cell wa

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05610.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Sealed plasma membrane vesicles were obtained in high purity from leaves ofCommelina communisL. by aqueous two‐phase partitioning. Based on the analysis of a range of markers, the preparations (U3+U3′ phases) were shown to be devoid of tonoplast, Golgi and thylakoid membranes, and showed only trace mitochondrial contamination. One‐third of the vesicles were oriented inside out and exhibited ATP‐driven45Ca2+transport [? 15 pkat (mg protein)−1]. Ca2+uptake into the vesicles had a pH optimum of 7.2 and apparent Kmvalues for Ca2+of 4.4 μMand for Mg‐ATP of 300 μM. Ca2+uptake, K+, Mg2+‐ATPase (EC 3.6.1.3) activity as well as glucan synthase II (EC 2.4.1.34) activity were all maximal at the same equilibrium density (1.17 g cm−3) on continuous sucrose density gradients. The protonophore carbonylcyanidem‐chlorophenylhydrazone (CCCP) did not inhibit the ATP‐dependent Ca2+transport into the vesicles, excluding a Ca2+/H+exchange driven by a proton gradient. ATP‐dependent Ca2+uptake was inhibited by erythrosin B (I50= 0.1 μM), ruthenium red (I50= 30 μM), La3+(I50= 10 μM) and vanadate (I50= 500 μM), but not by azide, cyanide and oligomycin. The calmodulin antagonists, trifluoperazine (I50= 70 μM) and W‐7 (I50= 100 μM) were also inhibitory, However, this inhibition was not overcome by calmodulin. Trifluoperazine and W‐7, on the other hand, stimulated Ca2+efflux from the vesicles rather than inhibit Ca2+uptake. Our results demonstrate the presence of a Ca2+‐ATPase in the plasma membrane ofC. communis. In the intact cell, the enzyme would pump Ca2+out of the cell. Its high affinity for Ca2+makes it a likely component involved in adjusting low cytoplasmic Ca2+levels. No indications for a secondary active Ca2+/H+transport mechanism in the plasma membrane ofC. communiswere obtained. Both, the nucleotide specificity and the sensitivity towards vanadate. distinguish the Ca2+‐ATPase from the H+‐translocating K+. Mg

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05611.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

By means of a biparametric cytofluorimetric analysis it is possible to distribute meristematic plant cells in a variety of cell cycle sub‐compartments, unidentifiable by DNA measurements alone. In this work, an asynchronous proliferating cell population of pea root meristems was divided into different sub‐compartments of the cell cycle phases, i.e. G1A, G1B, S. G2A and G2B on the basis of their DNA‐nuclear protein content. By means of the same biparametric analysis, differentiated mesophyll cells and quiescent cells of embryo roots, indicated as G0 and G2Q, were distinguished from cycling cells by their low nuclear protein content. These results conform to those of some analyses performed on animal cells in culture and show that it is possible to get a major insight into cell cycle kinetics and its control in a natural system such as root mer

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05612.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Experiments were conducted to test the possibility that organic amines inhibit ethylene production by inhibiting transport of the ethylene precursor, 1‐aminocyclopro‐pane‐1‐carboxylic acid (ACC), into the vacuole. α‐Aminoisobutyric acid (αAIB) was used as a model substrate to study ACC uptake into the vacuole in relationship to ethylene production in pericarp slices ofLycopersicon esculentumMill. cv. Liberty treated with and without organic amines and related substances. Organic amines (polyamines and other basic amines) inhibited αAIB uptake into the vacuole. These amines also enhanced ACC accumulation in the tissue and reduced the passive efflux of αAIB from the vacuole. Overall, ethylene production was inhibited. The inhibition of αAIB transport and of ethylene production followed a polyvalent cationic progression in the order polyamines>diamines>basic 1‐amino acids. Ca2+, but not Mg2+, strongly stimulated αAIB uptake into the vacuole and ethylene production. At equal concentrations, Ca2+counteracted the inhibitory effects of polyamines on both αAIB uptake and ethylene production. Competitive and irreversible inhibitors of polyamine biosynthesis stimulated αAIB uptake into the vacuole and ethylene production. The results indicate an apparent relationship between polyamines, ACC uptake into the vacuole and

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05613.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

[15N]‐depleted (NH4)2SO4applied to the soil in 1985 resulted in residual labeling of about 16% of the storage nitrogen (N) pool of mature walnut (Juglans regiaL. cv. Serr) trees in 1987. Application of [15N]‐depleted (NH4)2SO4fertilizer to a different set of mature walnut trees in 1987 allowed monitoring of the kinetics and utilization of N from current year uptake in 1987 and resulted in>20% labeling of fruit N following completion of leaf expansion. Redistribution of storage N to the new growth predominated during the spring flush of growth although N derived from the soil during current‐year uptake contributed increasingly during leaf expansion. Labeled N from current year uptake accumulated preferentially in the leaves as compared with reproductive organs during leaf expansion but subsequent to leaf expansion, fruit were more highly labeled with N derived from current‐year uptake than leaves. Pistillate flower abortion was coincident with an apparent competition for N among developing vegetative and reproductive organs and preceded the period of significant N contribution from current‐ye

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05614.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Vitamin D3and stigmasterol have been previously shown to stimulate growth, Ca2+fluxes and calmodulin synthesis inPhaseolus vulgarisroots. In this study, these sterols (10−9M) were shown to accelerate the incorporation of [3H]‐thymidine into DNA inPhaseolus vulgaris(L. cv. Contraancha) root apices, similarly to a mixture of the mitogenic plant growth factors 2,4‐dichlorophenoxyacetic acid and kinetin (4.6 μMeach). The effects of stigmasterol were blocked by flufenazine, a calmodulin antagonist. Analogously to stigmasterol, the plant hormones stimulated calmodulin synthesis as shown by double labeling of root proteins with [14C]‐leucine and [3H]‐leucine, respectively, followed by their separation on sodium dodecyl sulfate‐po‐lyacrylamide gels and a calmodulin affinity column, immunoblot analysis and cyclic AMP phosphodiesterase activation assays. The stimulation of root calmodulin formation by stigmasterol was abolished in the absence of Ca2+in the incubation medium and was mimicked by the Ca2+ionophore A–23187. The results suggest that the sterols, like plant mitogenic hormones, promote DNA synthesis, and that these compounds stimulate calmodulin synthesis as a consequence of their mitogenic activity.Ca2+appears to mediate the actio

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05615.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The influence of photoperiod on the metabolism of GA20inSalix pentandrawas studied by feeding [3H]‐GA20to seedlings which had been grown previously under long day (LD) or short day (SD) conditions. After 48 h in LD or SD, metabolites were separated on sequential, silica gel partition columns and reversed‐phase C18HPLC. The principal metabolite co‐chromatographed with [3H]‐GA1and this conversion was confirmed by feeding [2H]‐GA20, which was converted to [2H]‐GA1as identified by gas chromatography‐selected ion monitoring. Chromatographic evidence also indicated the minor conversion of [3H]‐GA20to [3H]‐GA8(via [3H]‐GA1) and trace conversion to [3H]‐GA29(GAs A1.8,20.29are native inSalix). Ethyl acetate‐insoluble [3H] metabolites were formed and could be cleaved by cellulase to release putative [3H]‐GA20and [3H]‐GA1suggesting the conversion to glucosyl conjugates of these GAs. Metabolism of [3H]‐GA20was slightly more rapid in plants previously grown under LD than SD, an effect which reflected the generally increased shoot growth under LD. However, altering the photoperiod after [3H]‐GA20addition had only a slight effect on the metabolism of [3H]‐GA20inSalixseedlings. This indicates that the conversion of GA20to GA1is not a controlling step in the photoperiodic regul

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1989.tb05616.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY