Retraction Note to: An assessment of transgenomics as a tool for gene discovery in Populus euphratica Oliv.

This article (Zhou et al. 2018) has been retracted by the authors because the sequence BIBAC 002A111F06 was incorrectly assigned to the wrong bacterial species. The BIBAC 002A111F06 sequence (GenBank Accession KC129717) reported in the paper was attributed to Populus euphratica Oliv. The BLAST search of this KC129717 sequence against the nr database at NCBI showed that it has very high similarity to a genomic sequence from the gram-negative bacteria Stenotrophomonas maltophilia. The bacterium associates with Populus euphratica Oliv. and DNA isolated from Populus euphratica Oliv. for the construction of the BIBAC clone library inlcuded DNA from Stenotrophomonas maltophilia. Therefore, the phenotype of the transgenic Arabidopsis line carrying the KC129717 sequence cannot be attributed to genes from Populus euphratica Oliv. The authors apologize for the confusion and misinterpretation of our data resulting from the incorrect sequence assignment. All authors agree to this retraction.

An assessment of transgenomics as a tool for gene discovery in Populus euphratica Oliv.

KEY MESSAGE: Transgenomics for gene discovery in Populus euphratica. Transgenomics, a member of the omics family of methodologies, is characterized as the introduction of DNA from one organism into another on a genome-wide scale followed by the identification of recipients with altered phenotypes. This strategy allows investigators to identify the gene(s) involved in these phenotypic changes. It is particularly promising for woody plants that have a long life cycle and for which molecular tools are limited. In this study, we constructed a large-insert binary bacterial artificial chromosome library of Populus euphratica, a stress-tolerant poplar species, which included 55,296 clones with average insert sizes of about 127 kb. To date, 1077 of the clones have been transformed into Arabidopsis thaliana via Agrobacterium by the floral dip method. Of these, 69 transgenic lines showed phenotypic changes represented by diverse aspects of plant form and development, 22 of which were reproducibly associated with the same phenotypic change. One of the clones conferring transgenic plants with increased salt tolerance, 002A1F06, was further analyzed and the 127,284 bp insert in this clone harbored eight genes that have been previously reported to be involved in stress resistance. This study demonstrates that transgenomics is useful in the study of functional genomics of woody plants and in the identification of novel gene(s) responsible for economically important traits. Thus, transgenomics can also be used for validation of quantitative trait loci mapped by molecular markers.