摘要:

Phosphofructokinase was partially purified from the mossBrachythecium rutabulum(Hedw.) Bt. Eur. and found not to be inhibited by 400 μMphosphoenolpyruvate, whereas spinach andChlorellaphosphofructokinases were inhibited over 80% by phosphoenolpyruvate at one‐fifth of this, concentration. Mixing experiments indicated that the insensitivity of the moss phosphofructokinase was not an artifact of the extraction procedure. Other kinetic and regulatory properties of moss phosphofructokinase were similar to those reported for the enzyme from other plan

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06051.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Primary leaves of intact bean plants (Phaseolus vulgarisL.) were treated with benzyladenine (BA) at different stages of ageing, BA promoted the synthesis of RNA, and soluble and insoluble proteins. The effects of BA stimulation differed depending on the age at which the leaf received the hormone treatment. In leaves attached to the plant, BA appeared to stimulate the rate of synthesis more than the rate of decomposition of RNA and protein, resulting in a net increase in RNA and protein. Both chloroplast and cytoplasmic ribosomes were still observed in intact yellowish green leaves. Polysomes in the cytoplasm increased remarkably when BA treatment was begun at late stages.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06052.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Cultivar differences have been reported in the protoplast yields fromPisum sativumroot cortical explants treated with preparations of commercial cellulase and pectinase. The presence of intracellular starch significantly influenced these protoplast yields. The application of gibberellin before or during the enzymic wall‐degradation increased the protoplast yields from two of the five cultivars tested. For tissues of‘Little Marvel’ pea roots, 10 mg 1−1of gibberellin most effectively increased the release of protoplasts when the hormone preceded the enzyme incubation. One mg 1−1of gibberellin was most effective at increasing the protoplast release when the tissues were treated with the hormone simultaneously with the wall‐degrading enzymes. Mitotic activity was significantly reduced in protoplasts derived from gibberellin‐tr

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06053.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Experiments were conducted under greenhouse conditions to investigate the effects of enhanced UV‐B radiation (280 to 320 nm) on height, fresh and dry weights, leaf chlorophyll and carotenoids, CO2uptake rates, and Hill activity in soybean (Glycine maxL. cv. Bragg). Plants were exposed for 6 h continuously from midmorning to midafternoon each day to UV‐B radiation which was provided by Westinghouse FS‐40 sun lamps filtered with 0.127‐mm cellulose acetate film (UV‐B enhanced) or 0.127‐mm Mylar S film (UV‐B Mylar control). Three different UV‐B enhanced radiation levels were tested: 1.09 (treatment T1), 1.36 (treatment T2), and 1.83 (treatment T3) UV‐B sun equivalent units (UV‐Bsec) where 1 UV‐Bsec= 15.98 mW·m−2of solar UV‐B obtained by applying EXP ‐[(α‐265)/21]2, a weighting function that simulates the DNA absorption spectrum, to the UV‐B lamp systems. These UV‐B levels correspond to a calculated decrease in stratospheric ozone content of 6%, 21%, and 36% for treatment T1, T2, and T3, respectively.Daily exposure of soybean plants to UV‐B radiation significantly decreased height, fresh and dry weights, leaf chlorophyll and carotenoid contents, and CO2uptake rates. Leaf pigment extracted in 80% acetone from UV‐B‐treated soybean plants showed considerable increase in absorption in the wavelength region of 330 to 400 nm with increased UV‐B radiation levels. Chloroplast preparations from leaves of T2and T3plants showed significa

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06054.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Root growth of white oak (Quercus albaL.) was observed under field conditions using a rhizotron. The effects of temperature, soil water potential, and leaf water potential were evaluated on three measures of root growth and development: root elongation rate, number of growing roots, and root growth intensity (sum of projected root area compared to the total root viewing area). Root elongation rate was linearly related to changes in soil temperature and soil water potential. At soil temperatures less than 17deg;C, temperature was the dominant factor affecting rate of growth, bat at temperatures greater than 17°C soil water potential became the important factor. Unlike root elongation rate, the number of growing roots and root growth intensity increased at cold soil temperatures (8°C) and at soil water potentials of‐0.3 to ‐0.8 MPa. At high soil water potentials (‐0.1 MPa) root elongation rate reached a maximum while the number of growing roots and root growth intensity were low. These differences showed that root growth and development were not exclusively affected by the soil environment. In addition, the relationship between root growth and predawn leaf water potential suggested that root growth was a contributing factor to the drought resistance of wh

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06055.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The phenolic acids and abscisic acid (ABA) of sugar pine (Pinus lambertianaDougl.) seeds coats, separated by high‐pressure liquid chromatography, were analyzed during 90 days stratification of the seeds. Although levels of seed coat phenolic acids and ABA declined significantly during, stratification, this decrease did not appear to be responsible for the loss of dormancy due to stratification. Lack of improved germination following washing, cracking, or removal of the seed coats, plus additional evidence, did not support a significant role for the seed coat in the dormancy of sugar pine seed

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06056.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The phenolic acids and abscisic acid (ABA) of sugar pine (Pinus lambertianaDougl.) embryos and megagametophytes, separated by high‐pressure liquid chromatography, were analyzed during 90 days stratification of the seeds. The phenolic acids occurred mainly as glycosides. Following hydrolysis, the majority of phenolics present could be identified as common benzoic and ciranamic acid derivatives. Levels of phenolic acids were relatively low in dormant seeds, but increased substantially in the embryos during stratification at 5°C, particularly cinnamic acid,p‐coumaric acid, ferulic acid, and one unknown. This active synthesis during stratification did not support an inhibitory function for phenolic acids. During stratification at 5°C, changes in ABA levels in both tissues followed a triphasic pattern, with no loss during the first 30 days, a significant decrease the second 30 days, and a lesser decrease the last 30 days. Loss of ABA from moist seeds at 25°C occurred three times as rapidly, so that by 30 days the ABA level of these seeds was equivalent to that of seeds stratified 90 days at 5°C; however, dormancy was not alleviated at 25°C. Application of exogenous ABA (10−7to 10−4M) to stratified seeds did not significantly reduce germination. Together, the above results did not support a primary role for ABA in the maintenance of dormancy in sugar pines.A correlated increase in phenylpropanoid metabolism and respiratory capacity with increased germinability during stratification suggests that loss of dormancy may be more closely dependent on increased levels of growth promoters or shifts in metabo

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06057.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Superoxide dismutase (SOD, EC 1.15.1.1) was identified from ripening cucumber (Cucumis sativusL.) and pepper(Capsicum annuumL.) fruits, Gel filtration revealed the presence of two major peaks of SOD with molecular masses of about 32 000 and 40 000. Peroxidase activity was observed mainly in material with a molecular mass above 70 000. SOD activity was inhibited by cyanide but not by chloroform‐ethanol, indicating a cupro‐zinc enzyme. SOD activity levels were high in immature‐green fruits of both species, declining in cucumbers to a minimum during the mature‐green stage and in peppers during the mature‐green and breaker stages. SOD levels increased again until peppers became orange and cucumbers turned yellow, and finally decreased with ripening. The possible connection between SOD activity and tolerance to sunscald is

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06058.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06059.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1981.tb06060.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY