-like Genes: Genome-Wide Analysis, Transcriptional Response to Cytokinin in Micropropagation, and Rootstock Transformation.

-like homeobox (KNOX) transcription factors are involved in plant development, playing complex roles in aerial organs. As species include important fruit tree crops of Italy, an exhaustive investigation of genes was performed using genomic and RNA-seq meta-analyses. Micropropagation is an essential technology for rootstock multiplication; hence, we investigated transcriptional behavior upon increasing 6-benzylaminopurine (BA) doses and the effects on GF677 propagules. Moreover, gene function in spp. was assessed by Gisela 6 rootstock transformation using fluorescence and peach transgenes. Based on ten spp., proteins fit into I-II-M classes named after Arabidopsis. Gene number, class member distribution, and chromosome positions were maintained, and exceptions supported the diversification of from subgenera, and that of from the other sections within . Cytokinin (CK) cis-elements occurred in peach and almond promoters, suggesting a BA regulatory role in GF677 shoot multiplication as confirmed by expression variation dependent on dose, time, and interaction. The tripled BA concentration exacerbated stress, altered CK perception genes, and modified transcriptions, which are proposed to concur in in vitro anomalies. Finally, Gisela 6 transformation efficiency varied (2.6-0.6%) with the genetic construct, with being more stable than lines, which showed leaf modification typical of overexpression.