Diversification of agriculturally important traits accelerated by polyploidization in Diospyros

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14654
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Horticultural science
• Research Institution: Kyoto University
• Principal Investigator: Akagi Takashi 京都大学, 農学研究科, 助教 (50611919)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 性決定 / 進化 / ゲノム / 果樹 / カキ / 倍数化 / 雌雄異株 / 雌雄異花同株

Outline of Final Research Achievements

In diploid persimmons, we previously elucidated the mechanism of sex determination that a Y-encoded pseudo-gene called OGI, via the production of small-RNAs against the gene encoding the female-determining factor MeGI, derives separate male and female individuals. On the other hand, in hexaploid Diospyros kaki, this regulatory mechanism leads to the formation of both male and female flowers (monoeocy), in genetically male individuals. Here we revealed that, in monoecious hexaploid persimmon, the DNA methylation levels on the MeGI is the key factor to determine flowert sexuality. Instead, OGI expression is generally undetectable, due to the SINE-like transposon insertion of a transposon in the 5' region of its promoter. This transposon insertion is highly methylated as is reported SINE families in other plant species, and is conserved in all Y-carrying D. kaki cultivars, suggesting either natural selection or a strong bottleneck for the silenced OGI gene during polyploidization.

Free Research Field

果樹園芸学