Poster: Epigenetics & gene silencing
Abs #
837: The maize Unstable factor for orange1 (Ufo1) induces global gene regulation changes & developmental defects
In maize, the PERICARP COLOR1 (P1) encodes a Myb-homologous transcription factor that regulates the synthesis of red phlobaphene pigments in kernel pericarp (outer layer of ovary wall) and cob glumes (palea and lemma). Multiple alleles of p1 are named based on the pigmentation of these tissues e.g. P1-rr plants have red pericarp and red cob, where as P1-wr conditions white pericarp and red cob glumes. To understand the tissue specific expression differences among different alleles of p1, we have recently characterized a dominant modifier called Ufo1 (Unstable factor for orange1;Chopra et al., 2003, Genetics 163:1135-1146). Ufo1 is an unlinked factor (maps on 10S) from p1 (maps on 1S) and its presence with P1-wr allele causes enhanced and ectopic expression of P1 regulated pathway. In addition, abnormalities such as stunted growth, leaf rolling, leaf spotting, and a downward curvature of the shoot are observed. In the current study, we performed microarray analysis to measure Ufo1- induced global changes in gene expression. The microarray data revealed that 65% of the differentially-expressed genes were up-regulated, while 35% were down regulated (p<0.05). Our results confirm the up-regulation of phenylpropanoid genes that were previously shown to be required for phlobaphene synthesis. Interestingly, our data analysis also shows transcriptional modification in genes that possibly play a role in epigenetic regulation of gene expression. In addition, we found that several cytoskeletal genes are strongly up-regulated in P1-wr Ufo1 pericarp. Our study indicates that Ufo1 may be affecting several epigenetic factors which in turn could be responsible for direct as well as pleiotropic defects.
