摘要:

THE BIOLOGY OF MOSSES.by D. H. S. RichardsonPRINCIPLES OF GENETIC MANIPULATION: AN INTRODUCTION TO GENETIC ENGINEERING. By R. W. Old&S. B. PrimroseSecond EditionHANDBOOK OF PLANT VIRUS INFECTIONS: COMPARATIVE DIAGNOSIS. Edited by EdouardKurstak.CYTOGENETICS. By JurgenSchulz‐SchaefferPLANT SCIENCE: AN INTRODUCTION TO WORLD CROPS. By J. Janick, R. W. Schery, F. W. Woods,&V. W. Rutt

ISSN:0140-7791    

DOI:10.1111/j.1365-3040.1982.tb00910.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11571638

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11571642

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11571646

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

摘要:

Abstract.Over the past three decades, many contributions have been made to the development of a mathematical basis for describing water transport in plant cells and tissue. This review paper attempts to summarize the more significant contributions and to outline the concepts upon which the various mathematical analyses are founded.The paper itself is divided into three major sections. Section I deals with the quantitative water relations of single plant cells. Basic equations are developed which describe the water statics and water dynamics of such cells. Included is a discussion of the theory and methods for measuring the various parameters (permeabilities, cell wall elastic moduli, etc.) which enter into the development. The section closes with a presentation of circuit analog models for single plant cells.Section II is devoted to a review and development of the water relations of plant tissues which contain numerous cells in series. Following a historical overview, various existing models are derived and physical tissue properties which enter the derivation are identified. The concept of ‘local equilibrium’ is discussed and circuit analog models for single cells are generalized and applied to several cells in series.The final section contains two example applications of water transport theory as it applies to plant tissue. One application involves radial water movement in a soybean hypocotyl while the other deals with water transport in a growing root tip. A summary at the end of the section is largely devoted to a discussion of the limitations of mathematical models dial are presently availa

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11571715

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Photosynthetic utilization of HCO, in leaves of Poiamogeton and Elodea occurs at the lower leaf side, with subsequent OH∼ release at the upper side. It is accompanied by transport of cations, in the present experiment K +, across the leaf. The resulting pH and K+ concentration changes near the leaf surface were recorded with miniature electrodes. From the pH and K+ concentration the concentrations of the different inorganic carbon species were calculated and compared with photosynthetic O, production. HCO−3utilization is accompanied by a drastic increase in the free CO2concentration near the lower epidermis. Experiments with CO2− and HCO3−free solutions showed an oscillating acidification near the lower epidermis and alkalinization near the upper epidermis. It is concluded that the acidification results from the activity of light‐dependent H+ pumps. The finding that an increase in pH at the upper side always coincided with a decrease at the lower in these experiments shows that the H+ pumps and the OH− extruding mechanism are coupled although occurring in different cell layers. Previously we have suggested that the first step in the process of photosynthetic HCO3−utilization is external conversion of HCO3−” by acidification caused by light‐dependent H+ pumps. The present results strongly support this hypothesis. Two possible pathways for the accompanying K + transport are discussed. The model presented here explains the known inhibiting effects of buffers and high pH on photosynlhet

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11571916

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.The large leaf rosettes of the so‐called ‘giant rosette’ plants which inhabit the alpine region of tropical mountains are composed of a great number of adult leaves surrounding a central cone of developing leaves. Upon onset of the nocturnal frost period the adult leaves nyctinastically bend inwards and form a night‐bud around the central leaf bud. The insulating effect of the night‐bud was analysed in four species:Senecio keniodendron, Senecio brassica. Lobelia keniensis and Lobelia telekiiwhich grow on Mt Kenya (Kenya). Freezing is avoided by a delay of cooling which is sufficient until rewarming by the next day's sunshine. A consequence of this delay is that the temperature in the nocturnal bud remains higher than that of the outer leaves which are often stiffly frozen after cold nights. Only one freezing point was detected on the leaf temperature recordings. Depending on the water state, the freezing points were in the range — 1°C to —4.2°C. Sucrose, amounting to 38% of the leaf dry weight, may act as a cryoprotectant for the cell membranes. Frost hardiness of the leaves, as determined with a laboratory method, was sufficient to enable the plants to survive during the nocturnal frost temperatures as measur

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11572080

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.PEP‐carboxylase was extracted and partially purified from nine species of the genus Sedum and three species of the genus Kalanchoe, all performing CAM. Immunological and molecular properties of these enzymes were compared. Molecular weight estimation with gradient slab gels showed identical molecular weights of about 232,000 for all PEP‐carboxylases. Ouchlerlony double‐diffusion analysis, immunotitralion and SDS polyacrylamide clectrophoresis indicated the presence of PEP‐c dimers consisting of monomers of MW 105,000 and 115,000. A model of PEP‐c substructure is proposed. The results are discussed in the context of CAM performance in the g

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11572356

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Cross and self pollen tubes were cultured in ‘Victoria’ plum flowers (Prunus domesticaL.) at 5, 10, 15 and 20°C. Pollen‐tube lengths measured at intervals were fitted by S‐shaped growth curves (logistic function) and the parameters of the curves used to derive a generalized model for pollen‐tube growth based on accumulated temperatures. Above the threshold of 2.5°C, maximum growth rate was 0.34 mm per day‐degree and the tubes reached half their final length at 16.6 day‐degrees above 2.5°C. The model indicates that fertilization of plum flowers requires 16–20 d at a constant temperature of 5°C after pollination, but only 3–4 d at 15°C. Mathematical expressions based on the model are given for estimating pollen‐tube penetration and growth rate from values of cumulated temperature since pollination, and for estimating the cumulated temperature necessary for pollen tubes to penetrate a given distance. Pollen‐tube growth rates were the same in detached flowers, flowers attached to twigs, and flowers on young, grafted trees in pots. In detached flowers growth stopped before fertilization could occur, but some embryo sacs were fertilized in both the remaining treatments. Accurate pollen‐tube growth assessments can therefore be made with detached flowers which are most convenient to use and can be accommodated in small incubators. Studies on fertilization, however, must use flowers on bulky

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11572417

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Acid phosphatase was found cytochemically in intercellular spaces in the root of Nymphoides peltata. Different methods, using lead salts and azo‐dyes, gave similar results. Reaction product appeared on material, possibly cytoplasmic, within the intercellular spaces and also against the outer walls of cells which formed the intercellular spaces. Possible functions of acid phosphatase in intercellular spaces are discusse

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11572437

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY