Reference "Mutations that cause amino acid substitutions at the invariant positions in homeodomain of OSH3 KNOX protein suggest artificial selection during rice domestication"

Reference ID

6584

Title

Mutations that cause amino acid substitutions at the invariant positions in homeodomain of OSH3 KNOX protein suggest artificial selection during rice domestication

Source

Genes & genetic systems, 2001, vol. 76, pp. 381-392

Authors (2)

Sato-Y

Fukuda-Y

Abstract

KNOX homeodomain (HD) proteins encoded by KNOTTED1-like homeobox genes (KNOX
genes) are considered to work as important regulators for plant developmental
and morphogenetic events. We found that OSH3, one of the KNOX genes isolated
from a cultivar of Oryza sativa (Nipponbare), encodes a novel HD, which has two
amino acid substitutions at invariant positions. Sequence analysis of OSH3 from
various domesticated and wild species of rice has revealed that these
substitutions are distributed only in Japonica and Javanica type of O. sativa,
two groups of domesticated rice in Asia. Surprisingly, nucleotide sequences in
the first intron are almost conserved in the rice strains that have the
substitutions at the invariant amino acids. Overexpression studies revealed that
these invariant amino acids are critical for the function of OSH3 in vivo. The
facts that these substitutions occurred specifically at the functionally
important amino acids and the sequences are conserved in intron where neutral
mutations accumulate suggest the substitutions at the invariant positions of
OSH3 have been fixed by artificial selections during domestication. Based on
these observations, we hypothesize that OSH3 is responsible for one of the
traits that are selectively introduced during the domestication of most of
Japonica and a part of Javanica type of rice.