Transcriptomic profile of key stages of sex differentiation in cassava flowers and discovery of candidate genes related to female flower differentiation.

To solve the breeding problem of the serious shortage of female cassava flowers, cassava variety 'Xinxianxuan 048' was used as the experimental material. Transcriptional sequencing technology was used to analyze the biological information of differentially expressed genes in female and male flowers during the critical period of cassava flower sex differentiation, explore the functions of differentially expressed genes and possible regulatory pathways involved, excavate candidate genes related to female differentiation, and verify the sequencing results by qRT-PCR method. The results showed that: There were 545 differentially expressed genes between male and female cassava flowers at the critical stage of gender differentiation. Among them, 48.63% of the differential genes were enriched in GO pathway of floral organ morphogenesis and development, and the genes enriched in plant phenylpropanol biosynthesis and plant hormone signal transduction were the most. AGL11, YABBY4, CRC, SUP, and other flower sex differentiation genes were significantly up-regulated in female flowers. Four genes of the cytokinin signaling pathway, including HK4, HPt4, ARR8, and ARR12, were significantly up-regulated in female flowers, while IAA14, GH3, SAUR22, and SAURR20, the early auxin response genes, were significantly down-regulated in female flowers. Therefore, the sexual differentiation of cassava flowers mainly involved the biological pathways of pollen, gametophyte, floral organ morphogenesis and development, and two metabolic pathways of plant phenylpropanoid biosynthesis and plant hormone signal transduction. Cytokinin and auxin might be the main hormones in cassava female flower differentiation. AGL11, YABBY4, CRC, SUP, HK4, HPt4, ARR8, and ARR12 may be positive regulators of cassava female flower differentiation. [ABSTRACT FROM AUTHOR]