FEASIBILITY OF ALTERNATIVE SELECTION METHODS FOR TRANSGENIC APPLE AND PEAR USING THE DETOXIFICATION GENE VR-ERE

Eutypine is a toxin produced by Eutypa lata, the causal agent of eutypa dieback of grapevines.
An eutypine detoxifying gene (Vr-ERE) encoding an NADPH-dependent aldehyde reductase converts eutypine into the corresponding alcohol, eutypinol, a non-toxic form of the toxin.
A variety of phytotoxic compounds containing an aldehyde group can act as substrates for this enzyme, therefore opening the possibility to use Vr-ERE as an alternative selection system for plant transformation.
Our preliminary experiments with apple and pear have demonstrated the following: 1) among the various substrates of VR-ERE, benzaldehyde (BD), a naturally occurring compound, is able to inhibit adventitious bud regeneration from apple as well as pear in vitro leaves, at concentrations ranging from 1 to 1.5 mM; 2) constitutive expression of Vr-ERE in transgenic ‘Greensleeves’ apple does not provoke any abnormal phenotype after one year of growth in greenhouse, but aldehyde reductase activity is reduced in all transgenic clones; 3) production of transgenic pear using BD instead of kanamycin as selection pressure is feasible, but the efficiency of the selection pressure seems low.
In conclusion, the efficiency of Vr-ERE as a selective gene to produce apple and pear transgenic plants is not yet proven and further research is needed.

International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species

E. Chevreau, J.P. Taglioni, C. Cesbron, F. Dupuis, S. Sourice, I. Berry, A. Bersegeay, J. Descombin, K. Loridon

aldehyde reductase, eutypine, Malus × domestica, Pyrus communis

https://doi.org/10.17660/ActaHortic.2007.738.29