Parenchyma bundle sheath

Figure 7.15 Forage digestibility prediction (leaf vascular bundle, shown in photomicrograph top left) analyzed for aromatic character of lignin in the parenchyma bundle sheath. The bundle sheath is less digestible if it is composed of lignin with a great amount of aromatic character. The 1509cm band area functional group map (top right) is indicative of...

Sedimentation of amyloplasts within the cell has been correlated with the capacity of the plant to perceive gravity. The buoyant mass of amyloplasts present in specialized cells in the center of the root cap and in the stem (depending on the plant species, in the endodermis, the bundle sheath, or in the parenchyma to the inside of the vascular bundle) would allow the amyloplasts to sediment inside the cell, where the cytosol would have a relatively low viscosity. This sedimentation would translate into a signal of an unknown nature, maybe through pressure onto a sensitive part of the cell or acting as a mechano transducer, etc. Whatever the nature of the signal, it eventually results in the asymmetry of the organ and its curvature. The isolation of starchless mutants of Arabidopsis thaliana and Nicotiana sylvestris has made... 

The cells concerned may occur as a bundle sheath (Figs. 6 and 7), or in the pericycle (Figs. 2 and 4), endodermis (Fig. 2), peripheral pith layers (Fig. 4), or even as phloem parenchyma as, for example, in Scopoliajaponica Maxim. (6). Detectable quantities are never found in the vessels. Careful... 

Recently, Jacobs and Gilbert (1983) succeeded in visualizing in pea stem tissue by means of an indirect immunofluorescence technique the presumptive auxin transport carrier in the plasma membranes at the basal ends of parenchyma cells sheathing the vascular bundles. 

Pig. 8o.—Photomicrograph of a representative portion of Greenbrier stem showing epidermis (,e.p.), cortex (c), endodermis (e.n.d.), cylinder sheath (c.s.), sclerenchyma fibers of closed collateral bundle ( ), fundamental parenchyma (J.p.), trachea (/). X 22. 

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