Abstract

Cytokinin (CK) is a hormone that controls division and regulates its differentiation. Cytokinin oxidase (CKX) plays a crucial role in the synthesis and metabolism of CK, regulating the homeostasis of CK through its family members. However, few reports have been on the CKX family members in rose ( Rosa chinensis ), which is an important aromatic plants using for essential oils. This study identified six RcCKX members, named RcCKX01-06, based on the location of linkage groups (LGs), from the reference genome. These six members were divided into four subfamilies, with each subfamily having similar motifs and elements. CKX members from four species (such as Arabidopsis , rice and soybean) were comprehensively analyzed, revealing similar motifs and gene structures within each subfamily. The analysis of cis -acting elements showed a close relationship between RcCKXs and hormones and abiotic stresses. Three pairs of RcCKXs exhibited collinearity with Arabidopsis , and 10 pairs showed collinearity with soybean. Real-time quantitative PCR (RT-qPCR) data indicated specific expression, especially during sprout stage, and a close association with abiotic stress through changes in expression levels. Additionally, quantification of cytokinin content and CKX activity demonstrated a strong relationship with RcCKX members. These results provide detailed information for the molecular breeding of roses.