Reference "The rice R gene family: two distinct subfamilies containing several miniature inverted-repeat transposable elements"

Reference ID

1512

Title

The rice R gene family: two distinct subfamilies containing several miniature inverted-repeat transposable elements

Source

Plant molecular biology, 2000, vol. 42, pp. 667-678

Authors (3)

Hu-J	Reddy-V-S
Wessler-S-R

Abstract

The R and B genes of maize regulate the anthocyanin biosynthetic pathway and
constitute a small gene family whose evolution has been shaped by
polyploidization and transposable element activity. To compare the evolution of
regulatory genes in the distinct but related genomes of rice and maize, we
previously isolated two R homologues from rice (Oryza sativa). The Ra1 gene on
chromosome 4 can activate the anthocyanin pathway, whereas the Rb gene, of
undetermined function, maps to chromosome 1. In this study, rice R genes have
been further characterized. First, we found that an Rb cDNA can induce
pigmentation in maize suspension cells. Second, another rice R homologue (Ra2)
was identified that is more closely related to Ra1 than to Rb. Domesticated rice
and its wild relatives harbor multiple Ra-like and Rb-like genes despite the
fact that rice is a true diploid with the smallest genome of all the grass
species analyzed to date. Finally, several miniature inverted-repeat
transposable elements (MITEs) were found in R family members. Their possible
role in hastening the divergence of R genes is discussed.