摘要:

Mechanical perturbations, in the form of either rubbing or wounding, cause ethylene evolution from bean internodes (Phaseolus vulgarisL. cv. Cherokee Wax). This evolution begins 45 to 60 min after perturbation or wounding and peaks about 2 h later. Maximal thigmomorphogenesis occurs if internodes are perturbed when they are 10 mm or less in length. Maximal ethylene evolution, however, occurs in longer internodes. When one internode is perturbed, ethylene evolution is not observed from other internodes even though they respond thigmomorphogenetically by exhibiting decreased elongation. Ethylene evolution is apparently a result of increased 1‐amino‐cyclopropane‐1‐carboxylic acid (ACC) production after perturbation. Inhibitors of ACC and ethylene synthesis block increased radial growth but not reduced elongation. Ethylene may therefore be only one of several factors causing thigmomorpho

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04575.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

In the Washington navel orange [Citrus sinensis(L.) Osbeck] an increase in the number of flowers results in a reduction of flower weight at anthesis and the initial fruit growth rate, and the number of developing fruitlets increases. Most of these fruitlets are shed during post‐anthesis, and the final set of fruit is unrelated to the number of flowers and to the total amount of metabolites and mineral elements used up in fructification but appears to be controlled by the capacity of the tree to supply metabolites to the developing fruitlets during post‐anthesis. When the number of flowers is too large, there is a reduction both in the number of initially developing fruitlets and in their growth rate. The final set of fruit is reduced through a different mechanism acting at anthesis and involving differences in mineral composition, which impairs the capacity of the fruit to act as a s

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04576.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Podolactones A and E and lycoritidinol inhibit growth induced by fusicoccin in dwarf pea (Pisum sativumL.) hooks and tips; however the inhibition is reduced at the highest fusicoccin concentrations. In short term experiments (3 h) on pea stem tissues, growth and proton efflux induced by fusicoccin are only partially inhibited by podolactone A and lycoricidinol. Auxin‐induced growth and proton efflux are completely suppressed by 10 μM lycoricidinol. The inhibitors do not affect ATP leve

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04577.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The germination of soybean (Glycine maxL. cv. Akita) seeds is accompanied by increased arginase activity in the cotyledons, and the enzyme is predominantly (84% for 5‐day‐old seedlings) recovered in the mitochondrial fraction (co‐purifies with succinate dehydrogenase) where it is located inside the inner membrane. When dry cotyledons from which the axis and testa have been removed surgically are imbibed for 6 h in water and maintained on filter paper during the subsequent incubation, there is little increase in mitochondrial arginase activity. However, if similar dry cotyledons are rinsed for 1 min after the sterilization of 3 min and maintained on filter paper from the beginning, the increase in enzyme activity is similar to that in the intact seedling. Thus the embryonic axis is not essential for the development of arginase in soybean cotyledon although the enzyme development was enhanced by the presence of the axis under the same conditions of incubation.The addition of actinomycin D, 6‐methylpurine and cycloheximide early in the incubation period strongly inhibits the development of mitochondrial arginase activity in the cotyledons, but chloramphenicol does not. However, actinomycin D and 6‐methylpurine had little effect on enzyme development when added after 2 days of incubation. These results suggest that arginase is synthesized in the cytosol and then transported into the mitochondria, while mRNA for arginase synthesis is produced for a limited time only during early ge

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04578.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The influence of temperature on the CO2exchange rates was investigated in winter rape plants (Brassica napusL. var.oleiferacv. Górczański) subjected to cold (2°C) pretreatment. After one or two days of cold pretreatment both photosynthesis and dark respiration still readily responded to changes in the temperature of measurement. Prolongation of plant exposure to cold caused not only a marked depression of photosynthesis but also photosynthesis became less temperature and light dependent. In contrast, prolonged cold pretreatment only slightly affected the sensitivity of dark respiration to temperature. In the cold‐pretreated plants the rate of dark respiration was higher that that in the untreated ones at comparable temperatures of measurement. To obtain a full reversion of the cold‐induced changes in photosynthesis and dark respiration rates the plants had to be exposed to higher (25°C) temperature for 3–7 days.It seems that low temperature brings about two types of effects in plants with regard to photosynthesis and respiration: a direct response consisting in the rapid and readily reversible reduction of both photosynthesis and respiration; and an indirect one which consists in long lasting modifications of photosynthesis and dark respiration rates and may be related to the cold‐induced changes in biochemical properties in photosynthetic and respirat

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04579.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The capacity of apple (Malus pumilaMill. cv. James Grieve and Golden Delicious) pot‐ and orchard‐grown trees to adjust osmotically in response to drought was investigated. Stressed leaves exhibited alterations in the moisture release curves when compared to well hydrated control leaves. Results suggest that osmotic adjustment occurred in both field‐ and pot‐grown trees. Water potential for zero turgor was lowered by 0.5 MPa in leaves of potted trees and by 1.1 MPa in leaves of field‐grown trees as a result of stress treatments. A decrease in the osmotic potential was responsible for that adjustment allowing the leaf to maintain turgor at lower water potentials and relative water contents. The extent of adjustment was similar for both potted and orchard trees despite the difference in the rate of stress imposition and its intensity. Changes in the concentration of sugars apparently contributed to this a

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04580.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Leaves of 10‐ to 12‐day‐old chlorescence lethalPisum sativumL. mutant are similar to control plants with respect to the content of chlorophylls, carotenoids, fatty acids and α‐tocopherol. Subsequent development of the mutant under high irradiation resulted in th destruction of the photosynthetic pigments, polyunsaturated fatty acids, α‐tocopherol, and also in the accumulation of liposoluble fluorescent products. No increase in the level of malondialdehyde was observed. In chloroplasts isolated from mutant plants the contents of chlorophyllaand β‐carotene were decreased to a greater extent than the more oxidized pigments (xanthophylls and chlorophyllb). The data obtained are discussed with special reference to the role of lipid peroxidation in the injury of plant cells under the action of visible light and to the antioxidative mechanisms stabilizing photosynth

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04581.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

From the results of shading experiments and irradiation of leaves from different directions, the pulvinus has been identified as the site of light perception in leaves of the sun‐trackerLupinus succulentusDougl. Within the pulvinus, the light‐sensitive region is located on the adaxial surface of the base of each leaflet. This is coincident with the site of the motor cells which are located in the peripheral four cell layers. Motor cells were visualized by microscopy and undergo dramatic changes in cell volume as leaflets incline to orient perpendicular to an oblique beam of light. Communication between leaflets appears to be minimal because each leaflet has the capacity to perceive and orient towards a light beam independently of the others. Hypotheses for the mechanism of directional light perception are discus

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04582.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Propionylcholine, a novel analogue of acetylcholine, was identified in green plants by gas chromatography/mass spectrometry. Propionylcholine was found in the leaves of the following species previously shown to contain acetylcholine and cholinesterase activity:Codiaeum variegatumBlume,Phaseolus aureusRoxb. cv. Berken,Plantago rugelliDecne.,Populus grandidentataMichx., andBetula pendulaRoth. The quantities of propionylcholine ranged from a high of 2.3 nmol (g fresh weight)−1inC. variegatumto a low of 0.11 nmol (g fresh weight)−1inP. rugelli. These amounts represented 6 to 8% of the levels of acetylcholine. In contrast to animal tissues which rarely synthesize propionylcholine, this compound was found in all species examined which represented five families of flowering pla

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04583.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Seedlings of barley (Hordeum vulgareL. cv. Conquest) were dark‐grown for 7 days and then transferred to light. The time courses of chlorophyllafluorescence induction underwent changes during greening periods of from 3 to 48 h. Yields of variable fluorescence during greening correlated with electron transport capacity via photosystem II (PS II) except at the early stage from 3 to 6 h. The discrepancy may result from there being only a small amount of light harvesting complex associated with PSII for 3 to 6 h greening. Oxygen quenching effects were interpreted as indicating the development of the electron transport system and the organization of light harvesting complex associated with PSII. The most intensive O2quenching of relative fluorescence is found during the early stage of greening when the ratio of the primary quinone electron acceptor (Q) to chlorophyll is hig

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb04584.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY