Molecular evidence of the influence of light duration on the differences in flower development of cut-flower rose varieties in summer and autumn

Cut rose (Rosa sp.) exhibits significant differences in flower development between summer andautumn. This study found that the flower diameter and length of cut roses in autumn were significantlylarger than those in summer, and the cell size and number of autumn flowers were also increasedcompared to summer flowers. Light intensity and duration treatments were set up. Under light intensitytreatment, there was no significant difference in flower diameter and length of cut roses. However,under light duration treatment, significant differences were observed in flower diameter and length,petal number, and dry and fresh weight of flower buds. Moreover, the cell size and number of petalswere also increased. Wax section observation of rose stem tips in the light duration treatment groupshowed that flower bud differentiation began on the seventh day in the 8h and 12h light durationtreatment groups. This was used as a key node for transcriptome sequencing. Transcriptome resultsindicated that genes involved in auxin, abscisic acid, and flowering process regulation might be the keygenes regulating the flower development process of cut roses in summer. Through qPCR verification,auxin regulatory genes RcARF8, RcSAUR72, and RcATL3; abscisic acid regulatory gene RcABI5-like7;and flowering regulatory genes RcRAV2 and RcATL3 were identified. Based on these findings, a modelwas constructed to explain the differences in flower development between summer and autumn.