Wisniewski, MichaelArtlip, TimothyLiu, JiaMa, JingBurchard, ErikNorelli, JohnDardick, Christopher2021-01-042021-01-042020-12-14Wisniewski, M.; Artlip, T.; Liu, J.; Ma, J.; Burchard, E.; Norelli, J.; Dardick, C. Fox Hunting in Wild Apples: Searching for Novel Genes in Malus Sieversii. Int. J. Mol. Sci. 2020, 21, 9516.http://hdl.handle.net/10919/101727<i>Malus sieversii</i> is considered the progenitor of modern apple (<i>Malus pumila</i>) cultivars and to represent a valuable source of genetic diversity. Despite the importance of <i>M. sieversii</i> as a source of disease resistance, stress tolerance, and novel fruit traits, little is known about gene function and diversity in <i>M. sieversii</i>. Notably, a publicly annotated genome sequence for this species is not available. In the current study, the FOX (Full-length cDNA OvereXpressing) gene hunting system was used to construct a library of transgenic lines of <i>Arabidopsis</i> in which each transgenic line overexpresses a full-length gene obtained from a cDNA library of the PI619283 accession of <i>M. sieversii</i>. The cDNA library was constructed from mRNA obtained from bark tissues collected in late fall&ndash;early winter, a time at which many abiotic stress-adaptative genes are expressed. Over 4000 apple FOX <i>Arabidopsis</i> lines have been established from the pool of transgenic seeds and cDNA inserts corresponding to various Gene Ontology (GO) categories have been identified. A total of 160 inserts appear to be novel, with no or limited homology to <i>M. pumila</i>, Arabidopsis, or poplar. Over 1300 lines have also been screened for freezing resistance. The constructed library of transgenic lines provides a valuable genetic resource for exploring gene function and diversity in <i>Malus sieversii.</i> Notably, no such library of t-DNA lines currently exists for any <i>Malus</i> species.application/pdfenCreative Commons Attribution 4.0 Internationalappleforward over expressionfoxmalus pumilamalus sieversiimalus × domesticafreezingArticle - Refereed2020-12-24https://doi.org/10.3390/ijms21249516