Genome adaptation during rice domestication

2014 Fiscal Year Final Research Report

• Project Area: Systematic study of chromosome adaptation
• Project/Area Number: 22125006
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: National Institute of Agrobiological Sciences
• Principal Investigator: IZAWA Takeshi 独立行政法人農業生物資源研究所, 植物科学研究領域, 上級研究員 (10263443)
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: イネ / 栽培化 / 紫黒イネ / イントログレッション / ゲノム

Outline of Final Research Achievements

The birth and spread of novel agronomical traits during crop domestication are complex events in plant evolution. Wild rice (Oryza rufipogon) has red grains due to accumulation of pro-anthocyanidins meanwhile most rice (Oryza sativa) varieties have white grains with a genetic defect allele in Rc bHLH gene. Some rice varieties that have black grains due to accumulation of anthocyanins are sporadically distributed in Asia although the birth and local spread of black rice remains unknown. Here, we show that the ectopic expression of another bHLH gene, Kala4, due to rearrangement of its promoter region is the origin of the black rice trait. The birth of black rice would have occurred in a subspecies Tropical Japonica and the causal alleles of Kala4 have spread to another subspecies Indica. Small sizes of genomic fragments of Tropical Japonica origins in some Indica varieties indicated that refined introgression occurred by natural crossbreeding during local spread of this trait.

Free Research Field

植物分子遺伝学