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Natural variation in E arly flowering1 contributes to early flowering in japonica rice under long days
Author(s) -
KWON CHOONTAK,
YOO SOOCHEUL,
KOO BONHYUK,
CHO SUNGHWAN,
PARK JOONWOO,
ZHANG ZHANYING,
LI JINJIE,
LI ZICHAO,
PAEK NAMCHON
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12134
Subject(s) - biology , genetics , quantitative trait locus , japonica , gene , missense mutation , botany , mutation
Natural variation in heading‐date genes enables rice, a short‐day ( SD ) plant, to flower early under long‐day ( LD ) conditions at high latitudes. Through analysis of heading‐date quantitative trait loci ( QTL ) with F 7 recombinant inbred lines from the cross of early heading ‘ H1 43’ and late heading ‘ M ilyang23 ( M 23)’, we found a minor‐effect E arly H eading3 ( EH 3 ) QTL in the H d16 region on chromosome 3. We found that Early flowering1 ( EL 1 ), encoding casein kinase I ( CKI ), is likely to be responsible for the EH3 / Hd16 QTL , because a missense mutation occurred in the highly conserved serine/threonine kinase domain of EL 1 in H 143. A different missense mutation was found in the EL 1 kinase domain in K oshihikari. In vitro kinase assays revealed that EL 1/ CKI in H 143 and K oshihikari are non‐functional. In F 7:9 heterogeneous inbred family‐near isogenic lines ( HNILs ), HNIL ( H 143) flowered 13 days earlier than HNIL ( M 23) in LD , but not in SD , in which EL 1 mainly acts as a LD ‐dependent flowering repressor, down‐regulating E hd1 expression. In the world rice collection, two types of non‐functional EL 1 variants were found in japonica rice generally cultivated at high latitudes. These results indicate that natural variation in EL 1 contributes to early heading for rice adaptation to LD in temperate and cooler regions.