Plant Molecular Biology

, Volume 73, Issue 4–5, pp 569–585 | Cite as

Compositional and transcriptional analyses of reduced zein kernels derived from the opaque2 mutation and RNAi suppression

  • Alessandra Frizzi
  • Rico A. Caldo
  • James A. Morrell
  • Meng Wang
  • Linda L. Lutfiyya
  • Wayne E. Brown
  • Thomas M. Malvar
  • Shihshieh HuangEmail author


Corn protein is largely made up of a group of nutritionally limited storage proteins known as zein. The reduction of zein can be achieved by a transcriptional mutation, opaque2 (o2), or a transgene targeting zein through RNA interference (RNAi). Zein reduction results in an increase of more nutritionally balanced non-zein proteins, and therefore enhance the overall quality of corn protein. In this study, the composition of mature kernels and the transcriptional profile of developing kernels of these two types of zein reduced kernels were compared. Both zein reduced kernels contained higher levels of lysine and tryptophan and free amino acids were 10–20-folds more abundant than the wild-type counterpart. We also found that free lysine contributed partially to the increased lysine in o2 kernels while protein-bound lysine was mainly responsible for the increased lysine in transgenic zein reduction (TZR) kernels. Although they had relatively similar gene expression patterns in developing endosperm, o2 kernels had greater transcriptional changes than TZR kernels in general. A number of transcripts that were specifically down-regulated in o2 were identified. Many promoter sequences of these transcripts contain putative O2 binding motifs, suggesting that their expression is directly regulated by O2.


Zein High lysine corn Opaque2 QPM Zein reduction 



We are grateful to the Monsanto trait development group at Mystic for the greenhouse care, and Charles Hagen for editing the manuscript.

Supplementary material

11103_2010_9644_MOESM1_ESM.xlsx (219 kb)
Supplementary material 1 (XLSX 218 kb)
11103_2010_9644_MOESM2_ESM.docx (799 kb)
Supplementary material 2 (DOCX 799 kb)


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Alessandra Frizzi
    • 1
  • Rico A. Caldo
    • 2
  • James A. Morrell
    • 2
  • Meng Wang
    • 3
  • Linda L. Lutfiyya
    • 2
  • Wayne E. Brown
    • 2
  • Thomas M. Malvar
    • 4
  • Shihshieh Huang
    • 1
    Email author
  1. 1.Calgene CampusMonsanto CompanyDavisUSA
  2. 2.Creve Coeur CampusMonsanto CompanyCreve CoeurUSA
  3. 3.Chesterfield CampusMonsanto CompanyChesterfieldUSA
  4. 4.Mystic ResearchMonsanto CompanyMysticUSA

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