Identification and evaluation of the novel genes for transcript normalization during female gametophyte development in sugarcane

Background: Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). Method: In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). Results: Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.