摘要:

Brushite purified phytochrome fromAvena sativaL. cv. Sol II was bound to phenyl Sepharose, octyl Sepharose, CNBr‐activated Sepharose and to anti‐phytochrome immunoglobulins immobilized on Sepharose. The spectral properties of phytochrome bound to anti‐phytochrome immunoglobulins and to phenyl Sepharose were similar to phytochrome in solution. Phytochrome bound to CNBr‐activated Sepharose or to octyl Sepharose showed reduced Pfrformation after red irradiation. The reversal to Prwith far‐red light was only partial but a further increase at 667 nm took place slowly in the dark. A peak at 657 nm was seen in the difference spectrum between CNBr‐activated Sepharose‐bound phytochrome kept in darkness and the identical sample immediately after a far‐red irradiation.The change in linear dichroism at 660 nm and 730 nm, induced by plane polarized red or far‐red light, was measured. It was computed that the long‐wavelength transition moment of phytochrome had an average rotation angle of 31.5° or 180°–31.5°. The substrate used for immobilization had a limited effect on the rotation angle. Phytochrome immobilized on CNBr‐activated Sepharose gave an angle of 27.8° and phytochrome immobilized on phenyl Sepha

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02406.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Knowledge of phospholipids in relation to cell cycle phases would facilitate the manipulation of tissue culture cells for crop improvement. Rice cells,Oryza sativaL. introduction PI 353–705, were initiated from anther cultures and grown as liquid suspensions. Replicate cultures were harvested for analysis at various time periods up to 21 days. Phosphatidylcholine (PC) and phosphatidylethanolamine (PEA) content rapidly increased 2.5 fold by 3 days, follwed by a progressive decrease in both compounds to 15 days to below initial transfer levels. There was an increase in PC and PEA back to transfer levels from 16 to 21 days. Cells in the linear phase were transferrred 11 days after inoculation to media minus sucrose. Carbohydrate starvation of the cells and subsequent release from inhibition with 3% sucrose resulted in partially synchronized cultures as seen by rapid [3H]‐thymidine incorporation up to 24 h followed by a decrease to a minimum at 72 h. Phosphatidylcholine and phosphatidylethanolamine increased linearly throughout the DNA synthesis period in synchronized cells, reaching a maximum at 48 h and 60 h, respectively. The levels of both compounds 72 h after release from sucrose starvation are only 30% of non‐starved controls 72 h after transfer to fresh

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02407.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Triadimefon [1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐(1,2,4‐triazol‐1‐yl)‐2‐butanone] changes the morphology and partitioning of dry matter in cucumber (Cucumis sativusL. cv. National Pickling) seedlings. The dry weights, potassium and cytokinin levels in the cotyledons and roots of the treated seedlings were higher, whereas the hypocotyl weights were lower than the controls. When etiolated intact seedlings or cotyledons excised from triadimefon‐pretreated dark‐grown seedlings were exposed to light, chlorophyll synthesis in the pretreated cotyledons was stimulated. Triadimefon does not have cytokinin‐like activity in the cucumber cotyledon greening bioassay, but appears to induce the plants to produce more cytokinims, probably by stimulating root growth. Hence it is proposed that the stimulation of chlorophyll production by triadimefon in cucumber cotyledons is mediated by maintaining high levels of potassium and c

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02408.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A red background illumination synergistically increased the sensitivity of the stomatal conductance response to low intensity blue light in wheat seedlings (Triticum aestivumL. cv. Starke II, Weibull). It also saturated the photosynthesis dependent mechanisms so that they did not respond to the low quantum fluence rates needed to activate the blue light mechanism. Thus dual beam experiments provide a suitable experimental approach to study the blue light mechanism for stomatal regulation in the intact leaf. Time course studies indicated that in short time experiments the enhancement effect of the red background light was primarily a result of the increase in conductance level rather than a direct effect of the red light. This was confirmed with experiments where the stomatal blue light response was enhanced due to partial stomatal opening in CO2free air as well as due to circadian rhythm. During long term experiments the response to blue light gradually decreased. It could then, however, be restored by a simultaneous red background light.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02409.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The stomatal conductance response to low intensity blue light was studied in wheat seedlings (Triticum aestivumL. cv. Starke II, Weibull) under red background illumination. Reciprocity was shown to be valid for illumination times from 10 s up to about 2 min. The action spectrum, constructed from fluence rate response curves, showed a maximum peak at 445–450 nm, another peak at 470 nm, a slight shoulder at 420 nm and a plateau between 370–400 nm. The relationship with action spectra for other blue light responses is discussed. The blue light response of wheat stomata did not exhibit action dichroism (the direction of the electrical vector of polarized blue light did not influence the response of the guard cel

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02410.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Field‐ and greenhouse‐grownAbies fraseri(Pursh) Poir. (Fraser fir) were analyzed for wind‐ or mechanically‐induced flexure changes. These changes included inhibition of stem and needle elongation, reinforcement of branch bases around the stem, and increased radial growth in the direction of the mechanical perturbation (MP). Mature trees exposed to high wind conditions were severely flag‐formed. These modified tree crowns had a lower drag than crowns of non‐flag formed trees in wind‐tunnel tests. In both field‐grown and greenhouse‐grownA. fraseri, MP induced a decrease in flexibility and increased elasticity of the stems. The increased radial growth of the stems overrode the increase in elasticity, resulting in the overall decrease in flexibility. The increase in radial growth caused by wind or mechanical flexure was due to greater cell divisions of the vascular cambium, resulting in increased numbers of tracheids. The decrease in stem elongation in these trees was due, at least in part, to a decrease in tracheid length. The potential biological and mechanical significance of these induced growth changes in trees are addressed. The data support the thigmomorphogenetic theory, which states that plants respond to wind and other mechanical perturbations in a way that is favorable to the plant for continued survival in w

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02411.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Twenty‐three open pollinated families (half‐sibs) and four controlled pollinated families (full‐sibs) ofPinus taedaL. (loblolly pine) were grown in a greenhouse and analyzed for changes induced by mechanical perturbation (MP). These changes included inhibition of stem and needle elongation, bracing of branch nodes, and increased radial growth in the direction of the MP. Inhibition of stem elongation was the least variable feature measured. Leaf extension and stem diameter were highly variable between half‐sibs. MP induced increased drag in greenhouse grownP. taedain wind‐tunnel tests. InP. taeda, MP induced decreased flexibility and increased elasticity and plasticity of the stem. The increased radial growth of the stems overrode the increase in elasticity, resulting in an overall decrease in flexibility. MP trees had a higher rupture point than non‐MP controls. Increased radial growth is a result of more rapid cell divisions of the vascular cambium, resulting in increased numbers of tracheids. The decreased leader growth is partly due to a decreased tracheid length in res

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02412.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Ethylene production was monitored for 48 h in two half‐sibs ofPinus taedaL. grown in the greenhouse and given mechanical perturbation (MP) by flexing; and for 22 h inAbies fraseri(Pursh) Poir, grown in the field and exposed to wind‐mediated MP. Both species produced a peak of ethylene 18 h after MP. Seedlings ofP. taedaexposed to MP for the duration of the growing season (preconditioned) produced less ethylene compared to non‐MP controls, with a peak production at 8 h. One half‐sib which responded to MP by an increase in radial growth produced 16 times more ethylene than another half‐sib which had no significant change in radial growth. PreconditionedA. fraseriproduced no significant quantities of ethylene after MP. The production of wound ethylene appears to be different from MP‐induced ethylene. When an ethylene‐generating solution was applied toP. taedaseedlings, it mimicked many of the morphological and mechanical characteristics of MP seedlings. The putative role of ethylene in the thigmomorphogenetic response

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02413.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

α‐1,4‐Glucan phosphorylase (EC 2.4.1.1) forms from light or dark grown shoots ofPisum sativumL. cv. ‘Kleine Rheinländerin’ have been studied using various electrophoretic techniques. The phosphorylase patterns of green and etiolated shoots differed. Etiolated shoots contained two enzyme forms, one residing inside and the other outside the etioplast; this was shown by electrophoresis of extracts of isolated etioplasts. Purity and intactness of the organelle preparation were ascertained by electron microscopy. Light‐grown shoots contained, in addition to these two enzyme forms, a third phosphorylase which appears to be chloroplast‐specific. The two plastidic phosphorylase forms differed slightly in their apparent molecular masses (as determined by non‐denaturing polyacrylamide gel electrophoresis) and in their affinities towards branched polyglucans (as revealed by affinity electrophoresis). The apparent affinity of the extrachloroplastic phosphorylase form to these polyglucans was orders of magnitude higher than that of the two plastidic enzyme forms. The development of the chloroplast‐specific phosphorylase pattern is under photocontrol. Investigations performed with red or far‐red illuminated wild‐type plants and with a pale mutant which has a highly reduced pigment and thylakoid content suggest that this photocontrol is me

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02414.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Cytokinin‐like substances in both healthy and infected (Plasmodiophora brassicae) Wor. strain S) roots ofBrassica campestrisL. ssp.pekinensiscv. Granat have been tentatively identified and quantified by HPLC. The isomers of the cytokinins could be seperated on a reversed phase column using a gradient elution with increasing amounts of methanol. Secondary plasmodia were isolated mechanically fromPlasmodiophora brassicaeinfected roots. The time course of adenine uptake and its conversion to cytokinins were investigated. Evidence is presented for the incorporation of [U‐14C]‐adenine intotrans‐zeatin by secondary pl

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1986.tb02415.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY