Transcript profiling in stem base of crown root less 1 mutant after ectopic expression induction by dexamethasome of CRL1

Lateral Organ Boundary Domain (LBD) transcription factors are specific of plants and are involved in the control of development. One LBD clade is related to the control of root development (Coudert et al., 2013, Mol. Biol. Evol. 30, 569-572). Belonging to this clade, CROWN ROOT LESS 1 controls the initiation of crown roots in rice (Inukai Plant Cell, 17, 1387-1396, Liu et al., 2005, Plant J., 43, 47-56). The aim of this study was to identify the genes that are regulated by CRL1. Transcriptome analysis in crl1 mutant plants where the CRL1 gene expression was ectopically induced revealed a set of 277 up regulated genes including a large part of genes encoding transcription factors and genes encoding proteins associated to hormone homeostasis, to cell division, expansion and differentiation. We transformed crl1 mutant plants with a construction allowing the control of CRL1 expression by exogenous dexamethasone. Three independents transgenic lines were used. Controls were untranformed or transformed with an empty plasmid crl1 mutant plants. Transcriptome profiling were conducted 4h and 8h after dexamethasone treatment to identify early CRL1-activated genes.