Enhanced removal of exogenous formaldehyde gas by AtFALDH-transgenic petunia

Abstract

We initiated this study to remediate indoor air pollution caused by volatile organic compounds by using plants. We isolated the glutathione-dependent formaldehyde dehydrogenase gene AtFALDH from Arabidopsis thaliana, inserted it into the expression vector pK2GW7, and introduced the gene into two purebred lines of Petunia hybrida to determine whether the gene would function in this ornamental plant. Seven shoots were regenerated from 248 explants cultured on the Murashige and Skoog basal medium. However, when the regenerated shoots were transferred to the second selection medium, only one shoot survived. The AtFALDH-transgenic T1 seeds were obtained from self-pollination of the single acclimated transgenic plant. These seeds produced 17 AtFALDH-transgenic T1 plants, 13 of which expressed the transgene, as determined by the PCR analysis. Among the 13 AtFALDH-transgenic T1 plants, 10 plants were confirmed by the Southern blot analysis to be identical to the transgenic plants and to possess three copies of the transgene. Furthermore, AtFALDH-transgenic T2 seeds were obtained from the self-pollination of the AtFALDH-transgenic T1 line, and the PCR analysis showed that 81 of the 105 AtFALDH-transgenic T2 plants exhibited the transgene. The transcription of the transgene was confirmed using the real-time PCR analysis in four of five plants that were selected randomly from the 81 AtFALDH-transgenic T2 plants. The AtFALDH-transgenic T2 plants removed 49.0 μg·m−3·cm−2 leaf area of formaldehyde during a 5-h measurement period, as compared with only 38.9 μg·m−3·cm−2 leaf area by the non-transgenic plants (a difference of 25.9%). Future work should focus on developing other AtFALDH-transgenic ornamental flora for use in the phytoremediation of formaldehyde gas.