Reference "The y1 gene of maize codes for phytoene synthase"

Reference ID

5400

Title

The y1 gene of maize codes for phytoene synthase

Source

Genetics, 1996, vol. 143, pp. 479-488

Authors (4)

Buckner-B	Miguel-P-S
Janick-Buckner-D	Bennetzen-J-L

Abstract

The cloned y1 locus of maize was sequenced and found to encode phytoene
synthase. Different "wild-type" alleles of the locus were found to differ by the
insertion of transposable elements in their promoter and polyA addition regions,
and by the length of a CCA tandem repeat series, without any obvious effect on
function of the gene. A dominant Y1 ("wild-type") allele was observed to be
expressed at highest levels in the seedling but also in the embryo and
endosperm. The Mu3 transposable element insertion responsible for a pastel
allele of y1, which gives lowered levels of carotenoids in the endosperm of
kernels and seedlings grown at high temperatures, was located in the 5' end of
the gene. Although the size of the transcript from this y1 mutation suggests
that the Mu3 element provides the promoter for this allele, leaf tissue in this
mutant line contained approximately normal amounts of y1 mRNA. A recessive
allele of y1, which conditions normal levels of carotenoids in the embryo and
seedling, but almost no carotenoids in the endosperm, was found to accumulate
normal amounts of y1 mRNA in the seedling and embryo, while y1 transcripts were
not detected in the endosperm.