SERPINB6 and infection: In this poplar, PTI was activated after infection, but further R-genes did not respond properly: of 64 TIR-NBS-LRRs and 119 CC-NBS-LRRs, only 1 TIR-NBS-LRR family, which is regulated by miR472b, was upregulated, whereas members of the miR482 superfamily and their targets from both groups of R-genes hardly responded to rust infection.