Microtubular Cytoskeleton of Free Endosperm Nuclei During Division in Wheat.

Abstract

Microtubular cytoskeleton of free endosperm nuclei during division in wheat was investigated using immunofluorescence labeling technique and confocal scanning laser microscopy. During interphase, microtubles forming a cage around a free nucleus were observed and the orientations of microtubuls (Mts) paralleled to long axis of the ellipsed-shaped free nucleus. During prophase, the orientation of the perinuclear Mts changes from parallel to long axis of a free nucleus to vertical to it, and subsequently the Mts constituted directly metaphase spindle Mts while the nuclear envelope broke down. Spindle Mts were observed during both metaphase and anaphase. A short lived cell plate was deposited in the just formed phragmoplast at either late anaphase or early telophase, but it disappeared subsequently resulting in the failure of cell wall formation. The perinuclear Mts were reconstructed initiating from the daughter nuclear envelopes at early interphase stage. The results suggested that changes of the Mts orientation during prophase might be associated with the determination of plane of nuclear division and the perinuclear Mts had a role in maintenance of the shape of interphase nuclei in syncytium of wheat endosperm.