Optimization of Rhizobium rhizogenes-mediated transformation for a diversity set of rose genotypes

P. Rüter, F. Wehrenberg, J. Bartels, T. Debener, T. Winkelmann
Roses belong to the most important ornamental plants worldwide. It is therefore of great interest to improve relevant traits like rooting ability, which can be accomplished by integrating bacterial genes via a novel breeding approach, utilizing Rhizobium rhizogenes-mediated transformation and subsequent regeneration of plants from hairy roots in an in vitro system. In order to optimize the protocol for hairy root induction in rose, several parameters were explored. Sonication was observed to have a significant positive impact on the formation of hairy roots, as did the utilization of whole compound leaves in comparison to leaflets or petioles. Additionally, compound leaves exhibited a greater ratio of hairy roots – identified using the green fluorescent protein (GFP) as reporter system – to adventitious roots when compared to stem slices. The bacterial strain ATCC 15834 outperformed strain LMG 150, while the application of Silwet L-77 as wetting agent appeared to be detrimental. To assess the efficacy of the optimized protocol, a diversity set of 41 garden and 63 cut roses genotypes were transformed, resulting in a successful transformation in 98% (102 of 104) of the genotypes regarding hairy root formation, with a strong genotypic effect. These data allow for further studies, including GWAS analysis to dissect the genetic factors affecting transformation capacity and hairy root formation in rose.
Rüter, P., Wehrenberg, F., Bartels, J., Debener, T. and Winkelmann, T. (2023). Optimization of Rhizobium rhizogenes-mediated transformation for a diversity set of rose genotypes. Acta Hortic. 1383, 225-234
DOI: 10.17660/ActaHortic.2023.1383.27
https://doi.org/10.17660/ActaHortic.2023.1383.27
Rosa hybrida, hairy roots, protocol, explant type, Silwet L-77
English

Acta Horticulturae