Studying aberrations of normal developmental processes like plant tumour initiation provides a great opportunity for understanding of systemic control of plant cells differentiation. Most well-studied example of plant tumour is the crown gall caused by Agrobacterium tumefaciens; much less studied are spontaneous tumours developing in plants with certain genotype, regardless of agrobacterial infection. In the present study, we used RNA-seq to analyse the changes in gene expression at the early stages of development of A. tumefaciens-induced tumours in radish seedlings. In our studies we used two closely related radish inbred lines contrasting in their ability to form spontaneous tumours. RNA-seq and qPCR analysis showed significant changes in the expression levels for numerous genes involved in different metabolic and developmental processes, and Gene Ontology analysis indicated many biological processes probably involved in the crown gall development in radish. For example, a unique result of our research is upregulation of genes related to photomorphogenesis and downregulation of senescence-associated genes in the young crown gall tumours. Differences in gene expression between the analysed radish lines included upregulation of pathways related to chromatin remodelling and protein targeting to chloroplast in the tumorous line along with downregulation of pathways of chaperone-mediated complex assembly and anthocyanin biosynthesis.