Fine Structure of Healthy and TMV‐Infected Tobacco Cells Grown in Tissue Culture

Abstract

AbstractThree types of tobacco (Nicotiana tabacum cv. Havana 38) callus: 1) healthy stem callus, 2) TMV‐infected stem callus, 3) TMV‐infected leaf callus; and leaves differentiated from healthy stem callus, and from TMV‐infected leaf callus were compared for fine structure. In addition, the fine structure was observed of plastids in cells of leaves differentiated from callus isolated from stem sections of TMV‐infected hybrid tobacco plants (N. tabacum cv. Havana 38 ×N. glutinosa) grown under high temperature. The cytoplasmic organelles in tissue cultured cells were similar to those in cells of greenhouse‐grown tobacco plants. Except for plastids, TMV infection did not noticeably affect morphologically other cellular organelles in tissue culture cells. In TMV‐infected leaf callus, numerous small bodies were seen in plastid‐like bodies, while vesicle‐like structures were observed in the stroma of plastids in leaves differentiated from callus of hybrid tobacco inoculated with TMV. Morphological variations of mitochondria, such as swelling and vacuolization of the inner matrix, occurred frequently in TMV‐infected leaf callus. Needle‐like crystalline inclusions or looped inclusions composed of many fine, long filaments were considered TMV particles orientated parallel to each other. The TMV particles were detected in the cytoplasm of tissue culture cells.