Differential sensitivities to gamma radiation of Phylloxera gall and normal grape stem cells in tissue culture

Abstract

The differential responses were observed of cells from tissue cultures of normal grape stem (GS6-24) and Phylloxera vastatrix Planch leaf gall (GP4-21) exposed to gamma radiation of 100 to 500 000 R from cobalt-60. The percentage survival of cells decreased with increased intensity of radiation. The mitochondria, spherosomes, and nucleus were visibly affected by radiation. The percentage survival of gall cells was lower than that of normal cells after exposure to the same radiation intensity. The irradiated cells did not recover regeneration even when exposed to the smallest dose of 100 R, though a certain percentage of cells survived during 28 days of observation. The effectiveness of 2-mercaptoethylamine hydrochloride (MEA), and 2-aminoethylisothiouronium bromide hydrobromide (AET) at 1 × 10−2–1 × 10−8 M in protecting the cells against gamma radiation was tested by incorporating them in liquid medium containing actively growing cells of normal and gall types. Observation of cells in microcultures exposed to 1000 R showed that MEA at 1 × 10−4 M and AET at 1 × 10−3 M decreased the lethality of radiation to normal grape cells considerably more than to the gall cells. The normal cells treated with 1 × 10−3 M AET and exposed to 1000-R radiation also divided.