Comparative RNA sequencing-based transcriptome profiling of Quercur robur: specific sets of genes involved in taproot and lateral roots emergence.

Root development is well recognized in model plants, with many studies focusing only on primary root growth or lateral root initiation. However, taproot vs lateral root development has rarely been explored using molecular tools, and even less is understood about how the molecular processes engaged in taproot elongation shape the emergence of lateral roots in trees in the time-dependent manner. We address how gene expression is associated with elongation of taproot and lateral root formation of Quercus robur L. In addition, we have analyzed how the exogenous application of hormones and inhibitors shapes the root architecture. We also revealed that lateral root formation and emergence corresponds to expression of genes at specific taproot length points. Therefore, our study suggests that the pattern of gene expression in the taproot tips is involved in the shaping of lateral root growth. In addition, we have shown that lateral roots are characterized by a set of genes that are distinct from those expressed in the taproot tips. Insights from this study contribute to better understanding root development in trees.