Analysis of allele-specific stripe-leaf rice mutants caused by disruption of OsEMF1 gene

Abstract

OsEMF1 gene shows relatively low similarity to Arabidopsis EMF1 which plays an important role in maintaining vegetative stage by suppressing the expression of MADS-box genes in juvenile stage. Rice osemf1 mutant shows up-regulation of several MADS-box genes, resulting in dwarfism, abnormal flower development, indicating OsEMF1 is also involved in transcriptional regulation. Interestingly, two out of four allelic mutant lines also show longitudinal white sector consisting of mesophyll cells lacking mature chloroplasts, resulting in stripe leaf. The reproducibility of the phenotype in two lines indicates that stripe leaf is allele-specific phenotype caused by osemf1 mutation. Overexpression of the mutant osemf1 gene in wild type leads to stripe-leaf phenotype, indicating that stripe-leaf is caused by a gain-of-function mutation of OsEMF1 gene. The comparison of the expression profile obtained by microarray analysis between the mutant and wild type is also presented.