摘要:

Incorporation of14C L-valine and14C L-leucine into protein of tissue slices of the avocado fruit was relatively high during the early stages of the climacteric rise, declined sharply thereafter, and was virtually absent at the peak. The incorporation of amino acids in the preclimacteric stage was markedly lower than during the early stage of the respiratory rise. By following incorporation in relation to uptake at several concentrations it was established that the results were not a reflection of endogenous dilution.Puromycin was effective as an inhibitor of incorporation but not of oxygen uptake. When respiration was at its maximum there was no protein synthesis. It was concluded, therefore, that the respiratory upsurge characteristic of the climacteric was not related directly to protein synthesis.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

Some factors controlling the differentiation of sporangia and gemmae in an isolate ofAchlya sp.were investigated by replacement culture technique. Factors in the replacement medium which affect differentiation were as follows: A) Calcium is required for the differentiation of both sporangia and gemmae. B) Calcium cannot be replaced by magnesium, potassium or sodium. C) Gemmae are induced when the replacement medium contains salt at 40 to 80 mm. D) The salt induction of gemmae is nonspecific, sodium, potassium, magnesium and calcium chlorides are equally effective.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

The effects of several base analogues and cycloheximide on RNA synthesis, protein synthesis, and cell elongation were studied in excised soybean hypocotyl. None of the pyrimidine analogues tested affected growth or protein synthesis; only 5-fluorouracil appreciably inhibited RNA synthesis. 8-Azaguanine and 6-methylpurine markedly inhibited RNA and protein synthesis and cell elongation. Cycloheximide effectively inhibited both cell elongation and protein synthesis.The results show that 5-fluorouracil selectively inhibited ribosomal and soluble RNA synthesis without affecting the synthesis of D-RNA. These results indicate that the requirement for RNA synthesis to support continued protein synthesis and cell elongation is restricted to the synthesis of D-RNA.5-Fluorouracil was incorporated into all classes of RNA in a form believed to be 5-fluorouridylic acid.Cycloheximide markedly inhibited the accumulation of ribosomal RNA, but the results indicate that CH did not inhibit, per se, the synthesis of ribosomal RNA. The accumulation of newly synthesized D-RNA was only slightly affected by cycloheximide. These results show that the inhibition of cell elongation by cycloheximide correlates with the inhibition of protein synthesis, but not with the effect on RNA metabolism.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

Inhibitor C, one of the inhibitory fractions of the extract of Carob fruit, reduces the amount ofα-amylase in the culture medium of endosperm halves of barley seed which have been treated with gibberellic acid as compared with seed halves treated with gibberellic acid alone. A similar reduction is found in theα-amylase produced by embryo halves of barley seed which have not been treated with gibberellic aci

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

A diploid potato (Solanum tuberosum) mutant called droopy wilts easily. Excised leaves of the mutant lost weight, and hence water, more rapidly and had many more open stomata than leaves of a normal sibling. Further, the stomata of abnormal plants remained open in wilted leaves. When the stomata of the abnormal mutant were closed by a chemical spray, its excised leaves lost water no more rapidly than normal. Thus, the wilting of the mutant must be caused by wide stomata. The wilting of the abnormal leaves and the small dry weight of the plants indicate the advantage of the stomatal hydrostat in the normal plants.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

Chlorella pyrenoidosawere allowed to photosynthesize for short periods of time in the presence of14CO2and HTO. Analysis of tritium and14C labeling of photosynthetic intermediate compounds showed that the T/14C ratio of glycolic acid was comparable to that of intermediate compounds of the photosynthetic carbon reduction cycle when photosynthesis was performed in nearly 100% oxygen and only slightly higher under steady-state conditions. It is concluded that formation of labeled glycolic acid as a consequence of its proposed hydrogen transport role in photosynthesis is quantitatively of limited importance compared to the net synthesis of glycolic acid from CO2.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

Phenylalanine ammonia-lyase activity was investigated in preparations representing various parts of sweetclover (Melilotus albaDesr.) plants ofCuCuandcucugenotypes. In contrast to other plant parts, very young leaves and stems ofCuCuplants displayed high phenylalanine ammonia-lyase activity. Initial leaf samples fromCuCuplants were approximately 3 times as high in enzyme activity as leaves fromcucuplants, but stems were only slightly higher in activity. Defoliation of the plants resulted in decreased enzyme activity, increasedo-hydroxycinnamic acid content, and essentially no difference in enzyme activity between the genotypes. It appears that phenylalanine ammonia-lyase activity in leaves is not primarily controlled by theCu/cualleles and that the reaction catalyzed by this enzyme is not the limiting step ino-hydroxycinnamic acid synthesis.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

The fatty acid composition of nonhardy Caliverde and hardy Vernal alfalfa roots as a function of the hardening process was determined by gas-liquid chromatography.The fatty acid contents of nonhardy Caliverde and hardy Vernal alfalfa root tissue increased approximately 2-fold during hardening. This increase was associated with hardening but could not be used to distinguish between varieties. The fatty acid composition of the alfalfa root changed during hardening due to the preferential accumulation of polyunsaturated fatty acids. The preferential deposition of linoleic and linolenic fatty acids caused an increase in the average number of unsaturated bonds in the fatty acids. Apparently, lipid metabolism of the roots was altered during hardening.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

The absorption of Rb+byEuglena gracillisvar.bacillariswas examined, and an active uptake process could be detected within 1 hour. This was established by experiments that included a time course study and metabolic depression by either reducing the temperature or by addition of 2,4-dinitrophenol.By treating the cells with 0.50 mg/ml chloramphenicol, the rate of glycine incorporation and Rb+uptake were inhibited. The possible role of protein synthesis in relation to ion accumulation is discussed.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB

摘要:

The chromophore of phytochrome, the plant photomorphogenic pigment, was cleaved from the associated protein. Chromatographic and spectral properties indicated that it was a bilitriene closely similar to but distinct from the chromophore of C-phycocyanin and allophycocyanin.

ISSN:0032-0889    

出版商:American Society of Plant Biologists    

年代:1966

数据来源: ASPB