Gene-dependent flavonoid 3′-hydroxylation in maize

  • Larson R
  • Bussard J
  • Coe E
  • 5


    Mendeley users who have this article in their library.
  • 19


    Citations of this article.


The influence of the gene Pr on flavonoid 3'-hydroxylase activity in maize is described. Specific activities are presented for the hydroxylase in seedlings and aleurone tissue homozygous dominant and recessive and heterozygous for Pr. Specific activity levels in both tissues increased in a nearly direct proportion with the increase in Pr dosage, which is consistent with Pr being the structural gene for the hydroxylase. Regression analysis of the gene dosage:enzyme activity comparison yielded correlation coefficients of 0.979 and 0.959 for the seedlings and aleurone, respectively. Quantitative identification of the cyanidin and pelargonidin in the aleurone indicated that cyanidin increased with an increase in dominant Pr, while pelargonidin decreased, although the increases and decreases observed were not directly proportional to the gene dosage. Comparison of the cyanidin/pelargonidin ratio to the gene dosage ratio in the different tissues showed a strong correlation (0.998), which demonstrates that the dosage of Pr controls the ratio of cyanidin to pelargonidin. Cyanidin was found at a low concentration in aleurone homozygous for pr. Hydroxylase activity in maturing field plants reaches its peak concentration near anthesis and is present at an appreciable concentration in mature plant tissue homozygous for pr, as well as in seedlings homozygous for pr. Suggestion is made that pr could be a hypomorphic allele or that a duplicate gene for Pr could exist to account for the hydroxylase activity in homozygous pr tissue. Evidence for the hydroxylase in the aleurone and the seedlings and the pigment ratio data from the aleurone suggest that Pr is indeed a structural gene for NADPH:flavonoid 3'-hydroxylase.

Author-supplied keywords

  • Zea mays
  • duplicate genes
  • flavonoid 3′-hydroxylase
  • flavonoids
  • gene
  • hypomorph

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • R. Larson

  • J. B. Bussard

  • E. H. Coe

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free