Cloning of ACO Gene and Inhibition of Ethylene Evolution in Tomatoes with RNA Interference

A fragment of 1 018 bp of ACO gene cDNA sequence was cloned from tomato (Lycopersicon esculentum) leaves incubated with pathogen using RT-PCR with two PCR primers designed according to the sequence of tomato cDNA clone (E11). The BLAST search result showed that the sequence presented a very high match with the ACO genes in the other plants and its homology was from 83% to 99%. Using this sequence, a RNA interference (RNAi) transformation vector (pD311) was constructed through the way of BP cloning and transformed into tomato. Twenty-seven regenerated plants with kanamycin resistance were obtained, showing that the transgene integrated into tomato genome was proved by PCR and Southern blot. The ethylene respiration amount of the RNAi transgenic tomato plants was measured by gas chromatography, resulting in that ethylene evolution was specifically inhibited in leaves and fruits of the transgenic plants.