摘要:

Two kinds of hydroxycinnamic derivatives can be found in tobacco: esters and amides. They do not accumulate in the same way during development. Esters, especially chlorogenic acids, are always present in all organs, whereas amides are observed only during certain periods in specific organs (from 47 days after sowing, in apical leaves, anthers and ovaries). A relationship has been found between accumulation of amides and flowering of plants grown at 20°C. By comparing amide accumulation as well as leaf emergence rate, both at a temperature that allows flowering (20°C) and at a temperature that inhibits flowering (30°C), it appears that amides begin to accumulate whenever a plant is ripening to flow

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02721.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Pollen embryos ofDatura innoxiaMill are produced in larger numbers from anthers on agar‐gelled medium containing polyvinylpolypyrrolidone than on control. The best response is observed with 0.5% polyvinylpolypyrrolidone. The effect is possibly due to adsorption of substances (phenolics) emanating from cultured anthers and inhibiting the development of pollen grains into embryo

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02722.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The effects of temperature on ribulose bisphosphate carboxylase activity were studied in two tomato (Lycopersicon esculentumMill.) cultivars which differed in sensitivity to high temperatures. The heat tolerant cultivar, Saladette, had a smaller reduction in photosynthesis and a smaller increase in mesophyll resistance then the sensitive cultivar Roma VF, after 24 h at 35 to 40°C. One hour in vitro treatments at 50°C decreased the activity of ribulose bisphosphate carboxylase extracted from Roma VF by 75%, while Saladette was not affected. Heat stress to the entire plant caused greater inhibition of ribulose bisphosphate carboxylase in the heat sensitive cultivar. Ribulose bisphosphate carboxylase activity in both cultivars decreased with heat treatment but recovered under normal temperatures. Ribulose bisphosphate oxygenase activity decreased similarly in both cultivars under 37/18°C day/night temperatures, which resulted in an apparent change in the relative carboxylase/oxygenase activity of the two cultivars. Carbonic anhydrase activity was slightly greater in Saladette than in Roma VF but no significant decrease in activity was observed in plants exposed to high temperatur

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02723.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The oxidation of exogenous NADH by Jerusalem artichoke (Helianthus tuberosusL.) tuber mitochondria was strongly inhibited at pH 7.2 by EDTA, EGTA and mersalyl and by chlorotetracycline in the presence of Ca2+. This inhibition disappeared at pH 5.5 where about 50% activity was found as compared to controls at pH 7.2. The rate of oxidation of NADPH at pH 5.5 was the same as for NADH but it was inhibited by 50% by both EDTA and mersalyl.Mitochondria fromArum maculatumspadices oxidised NADH and NADPH with pH optima of 7.2 and 6.5, respectively. In the presence of EDTA the optima shifted to 6.7 and 5.9, respectively, due to an inhibition at higher pH and a lack of inhibition at lower pH. At pH 6.7 NADH oxidation was completely insensitive to both EDTA and mersalyl whereas the oxidation of NADPH was inhibited by more than 50%. The inhibition of NAD(P)H oxidation by chelators at neutral pH was due to the removal of Ca2+from the membranes in both types of mitochondria. The differences observed in the properties of NADH and NADPH oxidation suggest that two different dehydrogenases are involved. Because of the strong pH‐dependence and the changes in chelator‐sensitivity in the physiological pH‐range 6–8 it is suggested that the properties of NAD(P)H oxidation provide the cell with important means of metabolic reg

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02724.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Tentoxin‐treated mung bean plants are shown to lack chloroplast polyphenol oxidase (PPO) by enzymatic, electrophoretic and cytochemical analysis. Incorporation of PPO (a protein coded by nuclear DNA) into the plastid may occur via concentration of the protein into inner envelope‐derived vesicles. PPO integration into the plastid is apparently blocked by a tentoxin treatment although fraction I protein (and hence the proteins for chloroplast ribosome production) is not affected by this fungal toxin. Both apical and etiolated plastids from teotoxin‐treated plants lack PPO. Thus, it is unlikely that the primary effect of tentoxin is due to the binding of the chloroplast coupling factor, as previously sup

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02725.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Differences in starch metabolism during seed development and germination of two soybean [Glycine max(L.) Merrill] genotypes with normal seed β‐amylase activity [‘Williams’ (Sp1band ‘Altona’ (Sp1b)] and two soybean genotypes with undetectable seed β‐amylase activity [‘Chestnut’ (Sp1au) and ‘Altona’ (Sp1)] were investigated. Starch and soluble sugar profiles were essentially the same during seed development and germination. Total amylase activity of Williams and Altona (Sp1b) peaked just prior to seed maturity and then dropped off slowly; whereas, the total amylase activity of Chestnut and Altona (sp1) was very low throughout seed development and germination. The differences in amylase activity between Altona (Sp1b) and Altona (sp1) was also seen in leaves. α‐Amylase activity was similar in the four genotypes when β‐amylase was inhibited with Hg2+but was higher in the two genotypes with normal β‐amylase activity when β‐amylase was inhibited with heat plus Ca2+. Low levels of starch phosphorylase activity were detected throughout seed development and germination, and the activity was similar in three of the genotypes and higher in Altona (sp1).The protein, oil and oligosaccharide contents of mature seeds of the four genotypes were similar. Altona (sp1b) and (sp1), which appear to be near isogenic lines, were not different in any morphological character or yield.Altona (Sp1b) showed greater hydrolysis of soybean seed starch than Altona (sp1), but the evidence indicates that the mutation resulting in greatly reduced or missing β‐amylase activity has no effect on starch metabolism of deve

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02726.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Water‐extractable sulfhydryl content of spinach leaf discs increased up to four‐fold when they were incubated with sulphate (10–100 mM) for 20 h in light or darkness. The accumulated sulfhydryl compound was reduced glutathione. An increased glutathione content did not result in a higher frost‐tolerance of the spinach leaf discs. Both freezing temperature and time of exposure to freezing, determined as the point at which 50% of the cells were killed, remained unchanged after incubation with sulphate. These observations suggest that a sulfhydryl compound as glutathione does not play a direct role in protection of plants against freezing

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02727.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Isonicotinyl hydrazide, glycine hydroxamate, aminoacetonitrile and KCN inhibited the conversion of glycine to serine in spinach (Spinacea oleraceaL. cv. Viking II) mitochondria. The site of inhibition for the different inhibitors was studied. Isonicotinyl hydrazide and glycine hydroxamate both inhibited the partial reactions glycine‐bicarbonate exchange and serine hydroxymethyltransferase. The inhibition was competitive for the exchange reaction and noncompetitive for serine hydroxymethyltransferase. Aminoacetonitrile at low concentration (1 mM) inhibited the glycine‐bicarbonate exchange specifically, whereas serine hydroxymethyltransferase was inhibited only at higher concentrations. Aminoacetonitrile was a competitive inhibitor for both reactions. The serine hydroxymethyltransferase was inhibited by KCN whereas the glycine‐bicarbonate exchange was only partially inhibited. The KCN‐inhibition of serine hydroxymethyltransferase was comp

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02728.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Brassinolide (BR), a naturally‐occurring‐steroidal lactone from rape (Brassica napusL.) pollen, was compared with auxin for activity in a number of bioassay systems. Responses similar to IAA were elicited by BR in bioassays based upon bean hypocotyl hook opening, elongation of maize mesocotyl, pea epicotyl and azuki bean epicotyl sections, and fresh weight increase in Jerusalem artichoke (2,4‐D used) and pea epicotyl sections. The azuki bean and dwarf pea epicotyl bioassays were much more responsive to BR than IAA (at 10 μM). Responses approximately two‐fold greater in magnitude were elicited by IAA in the maize mesocotyl, bean hypocotyl hook and Jerusalem artichoke bioassays. Little or no response was elicited by BR (0.01 to μM) in the cress root or decapitated pea‐lateral bud bioassays. A powerful synergism between BR and IAA was observed in the azuki bean, pea epicotyl and bean hypocotyl hook bioassays. Although, as previously reported, other steroidal substances are active in some of the bioassay systems tested, none compared with BR in magnitude and diversity of elicite

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02729.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Brassinolide (BR), a naturally‐occurring steroidal lactone was compared with GA3and kinetin for activity in a number of bioassays. BR was highly active in elongation bioassays employing the dwarf pea epicotyl and etiolated bean hypocotyl that are responsive to GA3but not IAA (at 0.01 to 10 μM). The elongation of the cucumber hypocotyl elicited by BR and GA3was reduced far more than that elicited by IAA, following removal of the cotyledons. BR, like GA3also inhibited betacyanin accumulation inAmaranthusseedlings and prevented adventitious root initiation in hypocotyls of mung bean, dwarf bean and cucumber. Application of BR promoted rather than retarded senescence ofRumexleaves.While almost half as effective as kinetin in promoting expansion of cucumber cotyledons, BR was ineffective in cytokinin bioassays involving expansion of dwarf pea epicotyl hooks, dark synthesis of betacyanin inAmaranthusand retardation ofXanthiumleaf disc senescence. Unlike the case with IAA, BR does not interact synergistically with GA3. BR has proven active in promoting stem elongation in plant bioassays responsive to either IAA or GA3, or to both phytohormones. This effect, coupled to its effect on adventitious root formation, qualifies BR as a unique plant growth substan

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb02730.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY