Study of Sexual-Linked Genes (OGI and MeGI) on the Performance of Androecious Persimmons (Diospyros kaki Thunb.)

Abstract

It is reported that the production of floral sexual phenotype in hexaploid monoecious persimmon (Diospyros kaki) is closely related to a pseudogene called OGI, and a short interspersed nuclear element (SINE)-like insertion (named Kali) in the OGI promoter leads to the gene silence. As a result, DNA methylation level of MeGI promoter determines the development of male or female flowers. However, the molecular mechanism in androecious D. kaki, which only bear male flowers, remains elusive. Here, real-time quantitative polymerase chain reaction (RT-qPCR), molecular cloning, and bisulfite PCR sequencing technique were carried out using 87 materials, including 56 androecious resources, 15 monoecious, and 16 gynoecious cultivars, to investigate the performance of OGI and MeGI on the specific androecious type of D. kaki in China. In conclusion, the Kali insertion was exactly located in the OGI promoter region, and the OGI gene and the Kali sequence were existing and conserved in androecious D. kaki. Meanwhile, we also demonstrated that the MeGI gene was widespread in our investigated samples. Ultimately, our result convincingly provided evidence that the low expression of OGI is probably ascribed to the presence of Kali displaying strong methylation in the OGI promoter, and low expression of MeGI, as well as high DNA methylation level, in the promoter was closely connected with the production of male flowers; this result was consistent with the monoecious persimmon model. Our findings provide predominant genetic aspects for investigation into androecious D. kaki, and future perfecting the sex-determining mechanisms in persimmon.

Identifying Genes Associated with Female Flower Development of Phellodendron amurense Rupr. Using a Transcriptomics Approach

“…DNA methylation can regulate plant sex by modifying sex-determining genes. As the sex switch in poplar, the ARR17 gene is silenced by male-specific DNA methylation [ 4 ]; the transition from male to female flowers in gynoecious melon results from DNA methylation in the promoter of CmWIP1 that can contribute to the development of male flowers through carpel abortion [ 5 ]; and the male flowers of Diospyros kaki are closely connected with the low expression of the female-determining gene MeGI because of DNA methylation [ 6 , 7 ]. In addition, DNA methylation can regulate plant sex by modifying sex-related genes in response to external cues.…”