Prosomes (proteasomes) of higher plants.

From different plant tissues such as tobacco (Nicotiana rustica), potato (Solanum tuberosum), and mung bean (Phaseolus radiatus), ring- or cylinder-shaped particles called prosomes were isolated by either sucrose gradient centrifugation or fast protein liquid chromatography (FPLC). These particles have a diameter of 12 to 14 nm and a length of 16 to 18 nm. They migrate under conditions of nondenaturing gel electrophoresis as one distinct band.

Energy content, storage substances, and construction and maintenance costs of Mediterranean deciduous leaves.

At monthly intervals water content, crude fibre, total and protein nitrogen, sugars, starch, total lipids, ash content and calorific total energy were measured throughout the lifespan of the leaves of the deciduous mediterranean shrubs Pistacia terebinthus L. and Cotinus coggygria Scop. From these data the construction costs and maintenance costs, as well as the construction costs of non-storage compounds and energy expenditure values were calculated.

Prosomes exist in plant cells too.

A 19S particle was purified from tobacco (Nicotiana rustica) leaf cells. Its density was determined as 1296 g/cm3 in Cs2SO4-DMSO gradients, indicating the presence of RNA and protein. Polyacrylamide gel electrophoresis (PAGE) revealed eight distinct proteins in the range of 20-30 kD and RNA in the range of 70-80 nucleotides.

[Seasonal variations in contents of some non-volatile carboxylic acids in Sempervivum tectorum L].

Isocitric, citric, malic, and succinic acids are found in S. tectorum. Their contents, measured at various times during the year, show remarkable changes.

[The influence of soil moisture on the carbohydrate content of some crassulaceous plants].

Plants of Bryophyllum tubiflorum were held 12 days, plants of Sempervivum tectorum 11 and 23 days without water. Then, the contents of sugars and starch were determined. In Bryophyllum the quantity of monosaccharides decreased, that of oligosaccharides and of starch increased.