摘要:

SUMMARYThe bioproduction of indole‐3‐acetic acid (IAA) and indole‐3‐carboxylic acid (ICA) from L‐tryptophan in root nodules and roots ofLupinus luteusand by the symbioticRhizobium lupiniwas studiedin vitro, and IAA degradation and the conversion of a number of related indole derivatives were also investigated. The results permit the conclusion that at least a substantial part of the large amounts of IAA present in the root nodules is produced via plant enzymes as a result of a metabolic alteration induced by the rhizobial infection. Young roots appeared to possess a high activity of IAA production from L‐tryptophan, but most of this production is masked by enzymatic degradation of IAA.According to the results of the IAA destruction experiments, cell‐free enzyme extracts of mature roots show the lowest activity, and the non‐dialyzed young root enzyme extract exhibits significantly greater activity than the dialyzed preparations. For the root nodule enzyme preparations this situation was found to be reversed, suggesting that the balance between promoting and inhibiting substances influencing enzymatic IAA degradation in nodule tissue is changed in favour of inhibition as a result of the rhizobial infection. Some interesting data concerning differences in IAA destruction behaviour between different strains ofRh. lupiniwere also obtained.The results of the comparative investigations concerning the conversion of a number of related indole derivatives indicated that there are some significant differences with respect to the conversion capacities of the different inc

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00161.x

年代:1970

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00162.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe influence of explants from tubers of Jerusalem artichoke on the culture medium was studied.Growth substances: indolyl‐3‐acetic acid (IAA), 2,4‐dichlorophenoxyacetic‐acid (2,4‐D) and naphthoxyacetic acid (NoxAA) rapidly disappeared from the medium as was shown in the ether extraction.When labelled IAA was introduced it appeared that a long extraction period with ether (48h) is necessary. IAA‐1‐14C decarboxylated more rapidly than IAA‐2‐14C. Thus all experiments were done with IAA‐2‐14C.The culturing procedure was standardized: 30 ml medium (minerals of Heller, 2% glucose, 0.8% agar) containing 10 ppm IAA and about 1.2 × 106cpm IAA‐2‐14C was used. Three cylindrical pieces of Jerusalem artichoke weighing each 160–180 mg were transferred to the medium. A device was made to avoid14CO2losses. The disappearance of IAA from the medium was followed during 10 days. During the first 5 days the pH of the medium increased from 4.5 to 6.5. The IAA content decreased and this decrease continued and reached 50% after 10 days. This probably explains why the tissue can be transferred, after 10 days, to a medium without auxin and can continue its development. The decarboxylation of IAA, naturally taking place, is much (10 ×) enhanced by the tissue. The problem now is, whether the tissue enhances the decarboxylation in the medium, or whether the tissue absorbs the intact IAA and secretes the decarboxy

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00163.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe kinetics of T1 absorption by excised barley roots were studied with respect to the time and concentration dependence, sensitivity to Ca, and interaction with Rb and Na.The following conclusions were drawn:T1 is bound by sites normally binding K.In the range of concentrations from 0 to 0.2 me/l, T1 is absorbed readily into the protoplasm but vacuolar accumulation is slow and tends to stagnate.Although O2uptake is progressively reduced in the presence of T1, this effect does not seem responsible for the stagnation of vacuolar absorption.Besides a competitive inhibition, there is a stimulation of vacuolar T1 transport by Rb but not by Na.The peculiarities of T1 absorption are tentatively explained on the basis of structural interactions between a macromolecular carrier and the ions transported.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00164.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYCaffeic acid inhibits the enzymatic degradation of IAA, probably by formation of semiquinones. These radicals then occupy the sites on the non‐IAA degrading peroxidases which are normally used for the transfer of the IAA free radicals, thereby closing pathway I (seefig.1). H2O2cancels this inhibiting effect by directing the flow of the IAA free radicals via pathway II to the cofacto

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00165.x

年代:1970

数据来源: WILEY

摘要:

SummarySome data on the leaf nodule symbiosis ofArdisia crispa(Thunb.) A.DC. are given.The nodule containing margins of the leaves contain more nitrogen and less ethanol‐soluble sugar than the midrib sections.14CO2photosynthesis experiments show a higher activity in the ethanol‐soluble as well as in the insoluble fraction of the margin than in those of the midrib section; the activity of the ethanol‐soluble sugars was, however, lower in the margin than in the midrib section.The leaves contain a red pigment of anthocyanic nature. Fixation of atmospheric nitrogen by the symbiont could not be det

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00166.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe perine in the leptosporangiate fern genusBolbitisas present in the mature sporangia either surrounds the individual spores or forms an intricate cellular structure by which the spores are interconnected. The perine appeared to consist in some species of 2 separate layers which are variously differentiated or not.Differences in the perine do not seem to provide evidence for keeping the generaEgenolfiaandBolbitisseparate, as was recently suggested by some Indian authors.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00167.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYRoot injury increases the indoleacetic acid oxidase activity of cucumber hypocotyl extracts. Both root injury and changes in IAA‐oxidase activity have been connected with resistance against fungal attack. A mechanism correlating the increased resistance following chemical or mechanical injury with IAA‐oxidase activity is propo

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00168.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYPhenylserine, benzoic acid and salicylic acid were isolated from cucumber seedlings after feeding DL‐threo‐β‐phenylserine to the root. Traces of salicylic acid were also found in untreated

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00169.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYIncubation of potato slices in aerated and non‐aerated ammonium sulphate media either alone or fortified with carbon and phosphorus sources induced variable losses in the total carbohydrate content. Whereas the content of reducing sugars was, in general, increased by the differrent treatments, those of starch and sucrose were decreased. In tissues fed with ammonium sulphate + ATP, the losses of starch were higher and those of sucrose were lower than the comparable losses in tissues fed with ammonium sulphate alone.Protein breakdown was operative in all ammonium sulphate media with no carbon source but supplemental addition of glucose led to a marked accumulation of protein‐N. Amino‐and total soluble‐N showed different levels in the different media. It is concluded that ammonium sulphate and glucose independently affected the protein content of the tissues and the fraction of proteins synthesized at the expense of glucose was increased in presence of phosphorus sources.Ammonium sulphate either alone or fortified with ATP caused an initial sharp stimulation followed by marked low rates of CO2production by potato slices. When combined with glucose, ammonium sulphate reduced the high rates of CO2output observed in its absence. This reduction of glucose respiration was overcome by the presence of phosphorus sources.The present results are discussed in relation to the action of ammonium sulphate when used either alone or fortified with phosphorus and carbon

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00170.x

年代:1970

数据来源: WILEY