Temperature-Dependent Programmed Cell Death Detected in Hybrids between Nicotiana langsdorffii and N. tabacum Expressing Lethality

Abstract

Interspecific hybrids of Nicotiana langsdorffii × N. tabacum showed hybrid lethality when they were transferred to 24°C after cultured at 34°C for 50 days. Characteristic features of programmed cell death (PCD) were detected in these plants, but no such features were observed when seedlings were transferred to higher than 26°C. Chromatin condensation and nuclear fragmentation were observed in protoplasts isolated from yellow and brown leaves of hybrid seedlings expressing lethality. Electrophoresis of total DNA isolated from the leaves of hybrid seedlings showed a DNA ladder patterns, suggesting nucleosomal fragmentation of DNA. These results suggest that PCD is accompanied by temperature-dependent lethality of hybrids between N. langsdorffii and N. tabacum.