Bronze-2 gene of maize: reconstruction of a wild-type allele and analysis of transcription and splicing

Plant Cell. 1990 Nov;2(11):1039-49. doi: 10.1105/tpc.2.11.1039.

Abstract

The maize Bronze-2 (Bz2) gene, whose product acts late in the anthocyanin biosynthetic pathway, has been cloned and its transcript has been mapped. We have developed a general procedure for reconstructing wild-type alleles from transposable element-induced mutants. An existing transposon-containing clone, bz2::mu1 [McLaughlin, M., and Walbot, V. (1987). Genetics 117, 771-776], was modified by replacing the region of bz2::mu1 containing the transposon with the corresponding polymerase chain reaction-amplified sequence from the progenitor allele that has no Mu insertion. Particle gun delivery of the reconstructed Bz2 gene to embryonic scutellar tissue lacking a functional Bz2 gene complemented the bz2 mutant phenotype, as demonstrated by the production of purple spots. Having cloned the wild-type allele, we then analyzed the Bz2 transcript, whose features include an 82-nucleotide 5'-untranslated leader, one small intron (78 base pairs) within the coding region, and multiple polyadenylation sites. Four Mutator transposon insertions that eliminate gene function were mapped within the 850-nucleotide transcription unit. We found that variable levels of unspliced Bz2 RNA are present in purple husk tissue; this finding may indicate that the expression of Bz2 is regulated in part at the level of transcript processing.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Base Sequence
  • Cloning, Molecular
  • DNA Transposable Elements / genetics
  • Introns / genetics
  • Molecular Sequence Data
  • Plant Proteins / genetics*
  • Polymerase Chain Reaction
  • RNA Splicing / genetics*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Transcription, Genetic / genetics*
  • Zea mays / genetics*

Substances

  • DNA Transposable Elements
  • Plant Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • BZ2 protein, Zea mays