Improvement in the ozone tolerance of poplar plants with an antisense DNA for 1-aminocyclopropane-1-carboxylate synthase

Abstract

Genetically transformed lombardy poplar (Populus nigra L. var. italica Koehne) were regenerated after the cocultivation of stem segments with Agrobacterium tumefaciens strain LBA4404, which harbored a binary vector that included an antisense DNA for ozone-inducible 1-aminocyclopropane-1-carboxylate (ACC) synthase from poplar leaves. Lower rates of ozone-induced ethylene production were observed in transgenic plants than in wild-type plants. Ozoneinduced visible damage was attenuated in these lines, and the extent of damage was positively related to the level of ozoneinduced ethylene production. In one of these ozone-tolerant lines, the levels of transcripts for ozone-inducible endogenous ACC synthases were suppressed compared with those in wild-type plants, demonstrating that ozone-inducible ACC synthases have a key role in the expression of leaf damage by ozone exposure. Thus, transgenic trees with air pollution tolerance were developed for the first time among woody plants. © 2011 The Japanese Society for Plant Cell and Molecular Biology.