Physiological and transcriptome analyses to infer regulatory networks in flowering transition of Rosa rugosa

Abstract

Rosa rugosa is a famous Chinese traditional flowering species with high economic value. Flowering transition is an important process in plant growth and development. Although characterization of the flowering transition process has made great progress in some plants such as model plants, the process in R. rugosa has not been rigorously characterized to establish a mechanism. In this study, the changes of buds during flowering transition in R. rugosa ‘Duoji Huangmei’ were analyzed through transcriptomic sequencing combined with morphological and physiological index determinations. Results showed that with the morphology changes of buds, both sugar and starch content showed a similar up-down pattern while phytohormones content displayed various trends, which implied that sugar, starch and phytohormones might play diverse roles during flowering transition in R. rugosa. Moreover, a total of 4363 differentially expressed genes (DEGs) were identified at three developmental stages. Among them, 74 DEGs were involved in metabolism, transport, and signal transduction of sugar, starch, and phytohormones, as well as photoperiod and vernalization response. We proposed that these DEGs were not regulated independently but interacted with each other to construct a gene-gene network to regulate flowering transition of R. rugosa, and the regulatory network from vegetative growth stage (S1) to flowering transition stage (S2) was more complicated. These results further enriched the study of flowering transition in Rosa and lay an important foundation for breeding new varieties with desired floral traits.

Keywords

• rosa rugosa
• flowering transition
• transcriptome sequencing
• degs