BEHAVIOR OF PLANTS UNDER EXTRATERRESTRIAL CONDITIONS: SEED GERMINATION IN ATMOSPHERES CONTAINING NITROGEN OXIDES

Abstract

Seeds of common plant species can be germinated in rarefied N atmospheres containing high proportions of individual nitrogen oxides (N2O, NO, NO2) or their mixtures. A buffering substratum of CaCO3 is especially beneficial, and the best responses were given thereon by rice and sorghum in the presence of certain nitrogen oxides as compared with N alone. Cell division in the sorghum shoot in N2/NO was demonstrated. Nitrogen dioxide was inhibitory under anaerobic conditions but much less so when O2 was present. It is concluded that, if ordinary terrestrial flora unselected for tolerance to the oxides of N are taken as a model, their prospects for growth in a nitrogen oxide-rich atmosphere would be good indeed, provided that the substratum prevents excess acidity and that NO2 is not present in overly great quantities.