DNA structure of mutant genes in the waxy locus in rice

The Waxy enzyme, a glucosyl transferase, is encoded in the waxy locus and catalyse the synthesis of amylose in the endosperm. The absence of or decrease in amylose in waxy mutants is caused by the absence or altered amount/activity of this enzyme. In two of the 14 mutants observed, DNA structural modification was found by Southern blot analysis. One showed entire deletion of the gene, which resulted in the complete absence of the enzyme. The other, in which the amylose content was intermediate between waxy and non-waxy, was rearranged in the DNA sequence. (author). 5 refs, 2 figs, 1 tab