Ectopic expression of AtBRUTUS (AtBTS) and comparison between Bnams4b-transgenic Arabidopsis and bts mutants suggested that Bnams4b may drive translocation of BTS to cause various toxic defects.
In Brassica napus, the widely used genic male sterile breeding system 7365ABC is controlled by two young genes, Bnams4b and BnaMs3.
These results indicate that new chimeric Bnams4b carries BTS from nucleus to chloroplast, which may disrupt the normal ubiquitin–proteasome system to cause toxic effects, and these defects can be compensated by BnaMs3−Toc33 interaction or environmental heat shock.
