Sucrose and starch synthesis in sugar cane plant

Zusammenfassung Im Gipfelknoten des ausgereiften Zuckerrohrs liess sich die Anwesenheit eines stärkebildenden Enzyms nachweisen, während die anderen stärkefreien Teile dieser Pflanze ein sukrosebildendes Enzymsystem enthalten. Diese Befunde stehen im Einklang mit der Speicherung von Stärke im Gipfelknoten und dem Fehlen von Stärke in den übrigen sukrosehaltigen Pflanzenteilen des Zukkerrohrs.     

Argyrophilic intranuclear bodies of plant cells

Summary Within interphase nuclei of meristematic cells of plants there are small spherical bodies that stain intensely with silver. Their number is related to the DNA content of the species.     

Inhibition of cytokinesis in plant cells by 6-dimethylaminopurine and puromycin

Summary Binucleate cells are produced in garlic root tip cells with puromycin and with 6-dimethylaminopurine (6-DMAP), the purine component of puromycin. The possibility that the effect of puromycin on cytokinesis is due to 6-DMAP-which appears to be without short term effects on protein synthesis-is discussed.This work was supported by AI 031871 from the Centre National de la Recherche Scientifique (M-C.B.) and the University René Descartes (M-C.B. and F.L.), Paris.The authors would like to thank Miss G. Daouse and Miss M. Delage for excellent technical assistance.     

Formation of the neuromuscular junction in cultures of rat embryonic cells]

The morphological evidence of the primary nerve muscle contacts are described. They consist of areas of cholinesterase activity (detected histochemically) localized on the myotube membranes and of mutiple clusters of ACh receptors whose 125I-alpha-bungarotoxin binding sites are revealed by radio-autography. After the stage of the primary nerve muscle contacts, some of which seem transient, characteristic neuromuscular junctions appear. These neuromuscular junctions which possess subneural infoldings are similar to the end-plates of the Rat in vivo.     

Extensive endoplasmic reticulum: a distinguishing feature of auxin-producing plant cells

Résumé Le cytoplasme des cellules végétales capables de synthétiser l'auxine est caractérisé par l'abondance du réticulum endoplasmique. Les cellules dont la croissance est stimulée par de hautes concentrations de cette hormone contiennent beaucoup moins de réticulum endoplasmique. D'où l'hypothèse que le lieu de synthèse de l'auxine (dans les cellules capables de cette synthèse) est peut-être le réticulum endoplasmique.

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This work was begun at Manhattan College, Bronx, New York, supported by USPHS grant No. CA 06955, the Anna Fuller fund, and the Christine Sonntag Foundation. The work was continued at the Boyce Thompson Institute, Yonkers, New York, and completed at the Wistar Institute with support from USPHS grant No. CA 10815.

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I am grateful to Dr.G. Hagen for theNicotiana tissues, Dr.J. Lippincott for theP. savastanoi cultures and to Mrs.B. di Gregorio andE. Manasse for competent technical assistance.     

Use of arrow-root powder in starch gel electrophoresis

Summary The arrow-root powder is used in electrophoresis as an alternative to potato starch. Its use is quite economical and this starch can be easily hydrolysed in any laboratory.The author is indebted to Dr M. M. Goil, Prof. & Head of the Department and Dr R. K. Sharma, Professor of Zoology, for their invaluable suggestions and help in various ways.     

Morphological return from mitotic prophase to interphase induced by RNase in plant cells

Summary In vivo treatment of prophasic meristematic cells with RNase shows that the cytological reaction is similar to that produced by protein synthesis inhibitors, and that the prophasic control of protein synthesis is earlier than the region where prophasic RNA is synthesized.     

Formation of intracellular canaliculi in reaggregated striated duct cells of rat submandibular gland during short-term stationary culture

Reaggregated striated duct cells of rat submandibular gland formed deep tubular invaginations of the cell membrane, i.e. intracellular canaliculi, which are not present in the original tissue, after 24 h of the stationary culture.     

The amylolysis of a substituted starch substrate

Zusammenfassung Bei Anwendung eines Stärkesubstrates in Verbindung mit einem im Kohlenstoffatom 6 kovalent gebundenen Farbstoffmolekül gelingt die differentielle Messung der - und -Amylase Aktivität im Reaktions-medium.     

Dynamics of proteins in Golgi membranes: comparisons between mammalian and plant cells highlighted by photobleaching techniques

In less than a decade the green fluorescent protein (GFP) has become one of the most popular tools for cell biologists for the study of dynamic processes in vivo. GFP has revolutionised the scientific approach for the study of vital organelles, such as the Golgi apparatus. As Golgi proteins can be tagged with GFP, in most cases without altering their targeting and function, it is a great substitute to conventional dyes used in the past to highlight this compartment. In this review, we cover the application of GFP and its spectral derivatives in the study of Golgi dynamics in mammalian and plant cells. In particular, we focus on the technique of selective photobleaching known as fluorescence recovery after photobleaching, which has successfully shed light on essential differences in the biology of the Golgi apparatus in mammalian and plant cells.