Using Aphids to Measure Turgor Pressure Inside Sieve Elements

Author(s):  
Nick Gould ◽  
Peter E. H. Minchin ◽  
Michael R. Thorpe
Author(s):  
James Cronshaw

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.


Author(s):  
R. D. Sjolund ◽  
C. Y. Shih

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.


2010 ◽  
Vol 3 (6) ◽  
pp. 1064-1074 ◽  
Author(s):  
Johannes Liesche ◽  
Hong-Xia He ◽  
Bernhard Grimm ◽  
Alexander Schulz ◽  
Christina Kühn

2021 ◽  
Vol 254 ◽  
pp. 106942
Author(s):  
Gokhan Camoglu ◽  
Kursad Demirel ◽  
Fatih Kahriman ◽  
Arda Akcal ◽  
Hakan Nar ◽  
...  

IAWA Journal ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 143-175 ◽  
Author(s):  
H.-Dietmar Behnke

Nondispersive protein bodies present in the sieve elements in addition to dispersive P-protein are characteristic features of many woody dicotyledons; their origin may be nuclear or cytoplasmic. While nuclear nondispersive protein bodies are found in only two families, the Boraginaceae and Myristicaceae, bodies of cytoplasmic origin are present in 39 of the more than 350 families screened. These results were obtained from 228 dicotyledons studied with the electron microscope and data of additional species from the literature. The terminology, origin, form and distribution of nondispersive protein bodies are discussed. Their ultrastructural composition is described as being predominantly spindle-shaped, compound- spherical, rod-shaped and rosette-like. Based on the data accumulated from over 450 species (of about 3000 screened) it is evident that their taxonomic range is confined to a few dicotyledon superorders. Compound-spherical nondispersive protein bodies are characteristic of most of the Malvanae/Violanae; spindle-shaped forms are restricted to the Fabaceae (Rutanae). Rosanae-Proteanae-Myrtanae and the Magnolianae are the only other superorders that contain nondispersive protein bodies in several of their families. Evolutionary trends and possible taxonomic consequences implied in this distribution are discussed.


Planta ◽  
1980 ◽  
Vol 149 (5) ◽  
pp. 445-453 ◽  
Author(s):  
U. Zimmermann ◽  
D. H�sken ◽  
E.-D. Schulze

Planta ◽  
1982 ◽  
Vol 154 (1) ◽  
pp. 94-96 ◽  
Author(s):  
A. J. Peel ◽  
S. Rogers

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