Inclusions in guard cells of tobacco affected with mosaic

Abstract does not appear. First page follows.

Literature contains conflicting reports on the occurrence of inclusions in stomatal guard cells of virus-diseased plants. (Sheffield (1936)),3 studying the effect of many viruses upon their appropriate hosts, reported that guard cells never contained inclusion bodies. Certain of the plants-tomato, tobacco, Hyoscyarrtus niger, and Solanurn nodifiorum—were checked for the distribution of plasmodesmata in leaf epidermis. Although these structures were abundant in ordinary epidermal cells, they were not observed in the walls between the guard cells and the adjacent epidermal cells. Sheffield therefore suggested that the absence of plasmodesmata prevented the virus from reaching the guard cells.

(Hirayama and Yuasa (1937)), however, found inclusions in guard cells of mosaic tobacco, which they studied in fresh sections treated with acetocarmine. Under the influence of the acetic acid the inclusions tended to become obliterated about an hour after treatment.

According to (Kassanis (1939)), plants (Nicotiana Tabacum, sylvestris, and qlutinosa; Solanum, Datura, and Hyoscyamus) affected by the severe-etch virus disease invariably contain intranuclear inclusions in the guard cells but no cytoplasmic inclusions of the x-body type common in other cells.

In the present study, leaves of Nicotiana Tabacum, Turkish variety, affected by the Johnson tobacco mosaic virus, strain 1, were examined for distribution of inclusion bodies, with special regard to the guard cells. The material was killed and fixed in a chrom-acetic-formalin and a formalin-acetic-alcohol mixtures, then imbedded, sectioned, and stained by ordinary procedures used in the paraffin method.