Nicotiana chloroplast genome

Summary N. accuminata has a chloroplast genome of 171 Kb which is larger than 160 Kb reported for N. tabacum. A physical map of the former has been constructed by SalI, BglI, and PvuII enzymes in comparison with N. tabacum. They both share identical restriction map except in the extra segment of N. accuminata. This extra segment is located on the right-hand border of an inverted repeat in the large-single copy region of N. accuminata. It contains the following restriction sites: two for BglI and SmaI; three for SalI and XhoI. The size of inverted repeat measured by electron microscope is 22.67±0.78 Kb and 19.28±0.61 Kb for N. accuminata and N. tabacum, respectively. This is the first case where a larger inverted repeat region accompanied by a larger genome size was found among over 30 Nicotiana species studied thus far.