A maize QTL for silk maysin levels contains duplicated Myb-homologous genes which jointly regulate flavone biosynthesis

Autor: Zhang, Peifen, Wang, Yibin, Zhang, Jianbo, Maddock, Sheila, Snook, Maurice, Peterson, Thomas
Zdroj: Plant Molecular Biology; May 2003, Vol. 52 Issue: 1 p1-15, 15p
Abstrakt: The maize p1locus coincides with a major QTL (quantitative trait locus) determining levels of maysin, a C-glycosyl flavone that deters feeding by corn ear-worm. The p1gene is tightly linked with a second gene, p2, and both genes encode similar Myb-domain proteins. We show here that maize cell cultures transformed with either the p1or p2genes expressed under a constitutive promoter accumulate transcripts for flavonoid biosynthetic genes, and synthesize phenylpropanoids and C-glycosyl flavones related to maysin. Additionally, maize plants that are deleted for the p1gene have reduced maysin levels and moderate silk-browning reaction, whereas plants with a deletion of both p1and p2have non-detectable silk maysin and non-browning silks. We conclude that both p1and p2induce maysin biosynthesis in silk, although the two genes differ in their expression and pigmentation effects in other tissues. These results show that a QTL for flavone biosynthesis actually comprises two tightly linked genes with related functions.
Databáze: Supplemental Index