摘要:

Unilateral pulse ultraviolet irradiation caused positively phototropic coiling (>180°) and curvature (≤ 180°) in the growth zone of dark‐grown broom sorghum (Sorghum bicolorMoench, cv. Acme Broomcorn and Sekishokuzairai Fukuyama) first internodes. Coiling was induced by irradiation at 257 to 302 nm, and proceeded to develop almost linearly during 72 h or more involving new tissue produced after irradiation. Curvature, caused at 308 to 413 nm and by red light, developed rapidly during the first several hours then slowly to cease by about 24 h, and did not surpass 120° even at the optimum photon fluences. Action spectra were higher towards shorter wavelengths, having a shoulder at about 287 nm, and could not separate the two photoresponses. The curvature was partially but markedly suppressed by far‐red following the ultraviolet irradiation, whereas the coiling was not affected. Possible involvement of a specific UV‐B photoreceptor and phytochrome in curvature and of a UV‐C photoreceptor in coiling

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06091.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Comparative studies on the control of root and shoot‐bud formation and plant regeneration have been undertaken in discs (1 × 6 mm in diameter) excised from tubers of potato (Solanum tuberosumL. cv. Irish Cobbler) cultured in vitro. The results clarified that the optimal culture conditions for shoot‐bud formation were quite different from those for root formation and, in conclusion, that (1) shoot‐buds were produced when cultured in modified White's medium containing 0.25Mmannitol with 2.3 μMzeatin and 0.57 μMindole‐3‐acetic acid (IAA) at 20°C under relatively high light irradiation, while (2) roots were readily formed when cultured in modified White's medium containing 29 mMsucrose with 4.7 μMkinetin plus 1.7 μMIAA at 3

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06092.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Tests were conducted to identify possible relations between carbohydrates and callusing‐rooting ofPinus banksianaLamb, cuttings. Terminals, upper stems, and basal (1 cm) stems of 90‐day‐old untreated seedlings and seedling cuttings were analyzed for sucrose, total soluble reducing sugar, starch and total non‐structural carbohydrate during propagation. Seedlings were evaluated in order to determine whether data for cuttings alone properly described carbohydrate‐callusing‐rooting relations under conditions where stock plants and cuttings were propagated in different environments. Results indicated that seedling terminals and upper stems, but not basal stems, accumulated the measured carbohydrates much like cuttings, though to lesser concentrations. Thus, carbohydrate accumulation by cutting terminals and upper stems would have been overestimated, based on cutting data alone. In terms of rooting, results indicated that: 1) Total carbohydrate accumulation in cutting basal stems was related to callusing‐rooting, but a cause‐effect relation was not established; 2) The positive relation between callusing‐rooting and total carbohydrate accumulation was primarily due to accumulation of reducing sugar and starch, with reducing sugar predominant. 3) Reducing sugar/starch concentration ratios were the most sensitive and convenient indicators of specific carbohydrate differences within and between seedl

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06093.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Highly purified exo‐polygalacturonase was obtained from suspension cultures of carrot (Daucus carotaL. cv. Kintoki) by dialysis at pH 5.2, chromatography on DEAE‐Sephadex A‐50 and on Sephadex G‐150, and preparative polyacrylamide disc gel electrophoresis. The enzyme did not attack the isolated carrot cell walls directly, but it had some effect on pectic polysaccharides extracted from the walls. The extracted polysaccharides were fractionated by DEAE‐Sephadex A‐50 column chromatography yielding four carbohydrate fractions. The major fraction (P‐3) was then reacted with the exo‐polygalacturonase. The enzyme treatment resulted in hydrolysis of approximately 18% of the glycosyl linkages of fraction P‐3 with the release of galacturonic acids. The molecular size estimated by Bio‐Gel A‐5m gel filtration was not markedly affected by the enzyme action, but the percentage of galacturonosyl residues was clearly reduced. The specific activity of exo‐polygalacturonase changed during the growth cycle, in rela

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06094.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A microsomal fraction was prepared by differential centrifugation from the homogenate of dark grown shoots of oats (Avena sativaL. cv. Sol II). Plasma membranes were prepared from the microsomal fraction by means of an aqueous polymer two phase partition method. The content of phytochrome in the microsomal fraction and the plasma membrane fraction, respectively, were studied after different irradiation treatments of the intact shoots. Red irradiation increased the content of phytochrome in both the microsomal and plasma membrane fraction, especially in the presence of Mg2+. The increase induced by red light was fully reversible by far‐red light for the plasma membrane fraction both in the presence and absence of Mg2+, in contrast to the microsomal fraction where Mg2+had to be omitted. KI treatment of the membranes destroyed the binding of phytochrome whereas agents such as KCI, EDTA, CaCl2and Triton X‐100, did not have this effect, indicating that the phytochrome attachment to the membrane is hydrophobic. This in vivo binding resembles to a large extent the one obtained in vitro by Sundqvist and Widell (Physiol. Plant. 59: 35–41, 1983) even though some differences between the phytochrome species and the membrane side exposed probably occur; so that the present interaction between phytochrome and the plasma membrane does not necessarily reflect the interaction that leads to physiological responses, and there could be more than one type of intera

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06095.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The interactions of green or red light with blue light on the dark closing ofAlbizzia julibrissinDurazz. pinnules have been investigated. Irradiations at 430, 450 and 470 nm progressively delay dark closing with increasing photon fluence rates. Red or green light alone has no effect. However, when the blue fluence rate is low, both red and green light interact with it and increase the delaying effect of the blue light. When the blue fluence rate is high, green light interacts with it to negate some of the effectiveness of the blue light, while red light has no effect. This is similar to results obtained previously with far‐red light. It is suggested that the same unidentified photoreceptor is operating in both the far‐red and blue regions. The results also indicate the presence of a blue‐only absorbing photoreceptor whose action is increased by phytoc

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06096.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Protoplasts isolated from 4‐day‐old hypocotyls of various species ofBrassica (Brassica napus, B. campestrisandB. oleracea) produced callus with high efficiency in media containing casein hydrolysate and high concentrations of the auxin 2,4‐D (4.5 μM). Cell division began after 24 h and 60% of the cells had divided after 48 h. In contrast, protoplasts isolated from stem and mesophyll of plants grown in vitro or in the greenhouse began to divide after a delay of 3–5 days. In these cases 40–50% of the cells had divided after 5 days as compared to 70% for hypocotyl protoplasts. To obtain a high frequency of regeneration, rapidly growing calli were transferred to media having a high cytokinin:auxin ratio as early as possible, usually 3 weeks after protoplast isolation. The average regeneration frequency for calli obtained from mesophyll protoplasts was 50%, while as many as 70% of the calli derived from hypocotyl protoplasts ofB. napusregenerated plantlets on a medium containing zeatin (9.1 μM) and IAA (0.6 μM). On the same medium regeneration ofBrassica oleraceawas obtained. A low percentage of calli (1%) fromBrassica campestrisformed shoots when cultured on a combination of zeatin (4.6 μM), BA (4.4 μM) an

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06097.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Essentially chlorophyll‐free preparations of mitochondria from different tissues of the same plant can be obtained by a combined three step preparation procedure involving differential centrifugation, partition in aqueous polymeric two‐phase system and centrifugation in a Percoll gradient. The polypeptide patterns of mitochondria from photosynthetic (leaves) and non‐photosynthetic (petioles and roots) tissue from spinach were compared by use of SDS‐electrophoresis.About 35 polypeptides were found in leaf mitochondria with molecular weights from 14 to 103 kdalton. The polypeptide patterns of the membrane fractions and matrix fractions showed great differences. The membrane fractions contained significantly more polypeptide bands than the matrix fractions. The polypeptide patterns of mitochondria from photosynthetic and non‐photosynthetic tissues showed some striking differences. The 15.9, 41.7, 50.7 and 101 kdalton polypeptides were clearly detected in leaf mitochondria but these polypeptides were not found or found in only small amounts in petiole and root mitochondria. The differences were mainly associated with the matrix fractions. Staining with 3,3′,5,5′‐tetramethylbenzidine and hydrogen peroxide for heme containing polypeptides showed that the polypeptides which differ do n

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06098.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The H+‐ and IAA‐induced growth responses of isolatedVigna radiata(L.) Wilczek hypocotyl segments were investigated concurrently with IAA‐induced H+excretion. The effects of external pH on these reactions were also studied. Experiments were performed with intact, peeled and abraded segments. Only abraded segments reacted to H+and to IAA. In short‐term experiments, the cuticle prevented proton efflux and influx; however, it allowed gradual ion movements which become measurable after 1 h. Both phases of the IAA growth response reacted to external pH. The interactions between these two phases and their pH dependencies are di

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06099.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The properties of cell wall pectinesterase (EC 3.1.1.11) fromVigna radiata(L.) Wilczek hypocotyl were investigated with immobilized and solubilized wall enzymes. Along the hypocotyl, the decrease of growth potential coincides with significant changes of the characteristics of the pectinesterase activities. As hypocotyl cells grow older, the proportion of ionically bound enzymes decreases and pH profile, sensitivity to cations and affinity for pectin change. The possible significance of these observations is discussed.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1984.tb06100.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY