March 1958, Volume 7 Issue 3

 

          Research Articles
Data to the Ecology and Taxonomy of the Cotinus genus
Author: A. P谷nzes C
Journal of Integrative Plant Biology 1958 7(3)
Abstract (Browse 1908)  |  Full Text PDF       
A Note on the Structure of Eichhornia Crassipes
Author: C. L. Lee
Journal of Integrative Plant Biology 1958 7(3)
      
    Eichhornia crassipes Solms is a common water plant widely distributed in China. The floating roots of which are often used as a laboratory material for demonstrating the growing point in the root. It has been enonemously considered by some anatomists that the root-tip contains four separate groups of initials which subsequently differentiate into four zones: root-cap, epidermis, cortex and stele. After careful re-examination, it is found that the root-tip contains only three groups of initials: calyptrogen, epidermo-cortical initials and pierome, and the auther agrees with the early workers who related this plant to the type of most Gramineae plants (e. g. Zea mays). The misrepresentation obviously arises from the fault that the sections were not strictly median.
Abstract (Browse 1980)  |  Full Text PDF       
妊技快扶忘 孜抉把技 把忘戒志我找我攸 我折快把快忱抉志忘扶我快 攸忱快把扶抑抒 孜忘戒
Author: 圾.妒.妤抉抖攸扶扼抗扯迅
Journal of Integrative Plant Biology 1958 7(3)
Abstract (Browse 1978)  |  Full Text PDF       
A Preliminary Report on the Paper Chromatography of the Catechins of Lung-Chin Tea Leaves
Author: Tang Su
Journal of Integrative Plant Biology 1958 7(3)
      
    The catechins of fresh leaves of Lung-Chin tea had been paper chromatographied on Whatman No.1 filter paper by using phenol-water, n-butanol-acetic-acid-water as solvents. In several batches, the juice was autoclaved under 15 1bs. pressure for 15 minutes, or inoculated with Aspergillus Niger. The results were shown in Fig, 1 and 2. Spots 1, 2, 6, 8, 10, 4, B, and Y were always present, while 9, 7, 3, and G appeared less frequently. The spots 1, 2, 6, 8, 10, 4, 9, 7, and 3 had been tentatively identified as m-digallic acid, 1-epigallocatechin, 1-epigallocatechin gallate, 1-epicatechin gallate, 1-epicatechin, gallic acid, dl-catechin, catechin 汐-gallate and dl-gallocatechin respectively. Spots B, G, and Y had never been mentioned by other workers. Spot B is probably a gallocatechin or a gallate of other polyphenol as it turns blue on spraying with FeCl3 solution and is not hydrolyzed by Aspergillus Niger. Spot Y is probably an organic acid as it is shown by bromocresol green. Spot G has not yet identified, it is richer in stems than in leaves.
Abstract (Browse 2170)  |  Full Text PDF       
Studies on Plant Respiration, II. Adaptive Formation of Nitrate Reductase in Rice Seedlings
Author: H. Y. Wu and P. S. Tang
Journal of Integrative Plant Biology 1958 7(3)
      
    Four-to-six-day old seedlings of rice (variety Yin-fang) were used to demonstrate adaptive formation of the enzyme nitrate reductase through substrate induction. These seedling were germinated on quartz sand with M/15 or M/30 phosphate buffer as culture medium. When so grown the seedling do not give nitrate reductase activity. When nitrate is added to the buffer solution or when the germinated seedlings were treated with nitrate solutions for spefified period of time nitrate reductase activity was clearly demonstrable in these seedlings. This is true whether etiolated or green seedlings were used as experimental materals. The optimum conditions for this process of adaptive enzyme formation were found to be: pH 5, 30 ⊥, and 6 mM of nitrate (as K and Na salts in equal amounts, in M/15 or M/30 phosphate buffer). Under these conditions nitrate reductase formation in these rice seedlings could be induced in one day for etiolated intact seedlings. In the intact green seedlings, an induction period of only 5 h is sufficient. With isolated roots of these rice seedlings, an induction period of only 3 h is sufficient for the adaptive formation of this enzyme under optimum conditions. When transferred back to nitrate-free media, the adapted seedlings lose their nitrate reductase activity. The time needed for this deadaptation is about 2 d. Ammonium sulfate is ineffective as substrate for inducting nitrate reductase formation in these seedlings. In fact it appears to expert an inhibiting action on its formation in presence of nitrate. Low oxygen tension does not significantly impede nitrate reductase formation in these rice seedling. At an oxygen concentration of 5%, nitrate reductase formation was found to be as intense as when the induction was carried out at 10% oxygen. Even when the induction was carried out at 1% oxygen, significant amounts of the enzyme was formed in these seedlings. These results are explained on the assumption that under such conditions reduction of nitrate by these seedlings furnish sufficient oxygen for their metabolic activity. The fact that under very low oxygen tension (1%) the R. Q. of the seedlings is greater than unity supports our view that under such conditions nitrate may serve as the oxygen donor in the respiratory process of the seedlings. The role of nitrate reductase in this case may be considered to be that of a terminal oxidase. Attention is called to the observation that adaptive formation of nitrate reductase is greatly enhanced in isolated roots to which scutellum tissues are attached. The function of scutellem in seedling metabolism merits further investigation. Rice seedlings were found to take up considerable amounts of nitrate in a nitrogen atmosphere. This appears to be at variance with the "anion respiration" theory of salt up-take. Experiments are being performed to clarify this point. The results of these experiments appear to furnish a convincing demonstration of the adaptive formation of nitrate reductase in rice seedlings (var. Yin-fang). This is perhaps the first clear instance in support of the formation of an adaptive enzyme in higher plants. The significance of this finding in relation to mineral nutrition of the rice plant as well in the general theme of the mechanism of adaptation of plants to their environment are discussed.
Abstract (Browse 2034)  |  Full Text PDF       
Phosphorylation and Starch Formation in Leaves
Author: Li Shu-jun
Journal of Integrative Plant Biology 1958 7(3)
      
    It has been shown in a previous paper that starch formation in leaf discs floating on sucrose solution is greatly enhanced by illumination. By using various inhibitors it has been found the increase is probably due to increased phosphorylation. The present paper reports further experiments with arsenate. It was found that in maleic buffer, arsenate inhibits starch formation in light 50% at 5 ℅ 10-4 M and 100% at 2℅ 10-3 M. In phosphate buffer (1/30 M) it inhibits only 20% and 50% at the respective concentrations . The arsenate inhibition and its competitive nature with phosphate confirmed the previous conclusion that starch formation is through phosphorylation. Further experiments were made in air, in oxygen and in nitrogen. In dark, starch formation is proportionally to oxygen tension, but the maximum amount of starch formed even in flowing oxygen is far less than that in light without oxygen . It is clear therefore that oxidative phosphorylation plays only a minor role in comparas on with the phosphorylation due to light (Photosynthetic phosphorylation of Arnon). In light, starch formation shows no correlation with oxygen partial pressure. However, a very small amount of oxygen appears to be necessary for optimal activity, possibly connected the formation of co-factors. Microscopic examination of leaf sections showed that the starch formed is localized in the chloroplasts, the result collaborates the contention of photosynthetic phosphorylation.
Abstract (Browse 1867)  |  Full Text PDF       
 

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