Fine structure of plasmodesmata in mature leaves of sugarcane.

摘要: The fine structure of plasmodesmata in vascular bundles and contiguous tissues mature leaf blades sugarcane (Saccharum interspecific hybrid L62–96) was studied with the transmission electron microscope. Tissues were fixed glutaraldehyde, without addition tannic acid, postfixed OsO4. results indicate that differs among various cell combinations a cell-specific manner, but three basic structural variations can be recognized leaf: 1) Plasmodesmata between mesophyll cells. These possess amorphous, electron-opaque structures, termed sphincters, extend from plasma membrane to desmotubule near orifices plasmodesmata. cytoplasmic sleeve is filled by sphincters where they occur; elsewhere it open entirely free particulate or spokelike components. tightly constricted has no lumen within convoluted tubule an lumen. 2) traverse walls chlorenchymatous bundle-sheath cells mestome-sheath In presence these are modified suberin lamellae walls. Although quite narrow lumens desmotubules lamellae, sleeves still discernible appear contain substructural components there. 3) parenchymatous bundles. strongly resemble those found roots Azolla, their closed for entire length length. exhibited compared proposed widely-adopted model plasmodesmatal structure.