Abstract
We reported previously that atmospheric nitrogen dioxide (NO2) at an ambient concentration almost doubled plant growth and biomass1). Histological analysis of rosette leaves of Arabidopsis thaliana C24 revealed that the increase in shoot biomass by NO2 is attributable to increase in cell size but not to that in cell number. In this study, we investigated possible involvement of the endoreduplication in the increase in cell size by NO2. One-week-old seedlings grown in air without NO2 were grown for 4 weeks more in air with (+NO2 plants) or without (-NO2 plants) 50 ppb NO2, after which the ploidy level of leaf 8 of each of the plants was determined. We found that the ploidy level did not differ between +NO2 and -NO2 plants. This finding suggests that the endoreduplication is not responsible for the NO2-induced cell expansion.
1) M. Takahashi et al. (2005) New Phytol 168: 149-154.
