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Article
QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions
Proceedings of the National Academy of Sciences of the United States of America
  • Ling Li, Iowa State University
  • Wenguang Zheng, Iowa State University
  • Yanbing Zhu, Iowa State University
  • Huaxun Ye, Iowa State University
  • Buyun Tang, Iowa State University
  • Zebulun W. Arendsee, Iowa State University
  • Dallas Jones, Iowa State University
  • Ruoran Li, Iowa State University
  • Diego Ortiz, Iowa State University
  • Xuefeng Zhao, Iowa State University
  • Chuanlong Du, Iowa State University
  • Dan Nettleton, Iowa State University
  • M. Paul Scott, United States Department of Agriculture
  • Maria G. Salas-Fernandez, Iowa State University
  • Yanhai Yin, Iowa State University
  • Eve S. Wurtele, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-2015
DOI
10.1073/pnas.1514670112
Abstract
The allocation of carbon and nitrogen resources to the synthesis of plant proteins, carbohydrates, and lipids is complex and under the control of many genes; much remains to be understood about this process. QQS (Qua-Quine Starch; At3g30720), an orphan gene unique to Arabidopsis thaliana, regulates metabolic processes affecting carbon and nitrogen partitioning among proteins and carbohydrates, modulating leaf and seed composition in Arabidopsis and soybean. Here the universality of QQS function in modulating carbon and nitrogen allocation is exemplified by a series of transgenic experiments. We show that ectopic expression of QQS increases soybean protein independent of the genetic background and original protein content of the cultivar. Furthermore, transgenic QQS expression increases the protein content of maize, a C4 species (a species that uses 4-carbon photosynthesis), and rice, a protein-poor agronomic crop, both highly divergent from Arabidopsis. We determine that QQS protein binds to the transcriptional regulator AtNF-YC4 (Arabidopsis nuclear factor Y, subunit C4). Overexpression of AtNF-YC4 in Arabidopsis mimics the QQS-overexpression phenotype, increasing protein and decreasing starch levels. NF-YC, a component of the NF-Y complex, is conserved across eukaryotes. The NF-YC4 homologs of soybean, rice, and maize also bind to QQS, which provides an explanation of how QQS can act in species where it does not occur endogenously. These findings are, to our knowledge, the first insight into the mechanism of action of QQS in modulating carbon and nitrogen allocation across species. They have major implications for the emergence and function of orphan genes, and identify a nontransgenic strategy for modulating protein levels in crop species, a trait of great agronomic significance.
Comments

This article is from Proceedings of the National Academy of Sciences of the United States of America (2015): 14734, doi: 10.1073/pnas.1514670112.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Citation Information
Ling Li, Wenguang Zheng, Yanbing Zhu, Huaxun Ye, et al.. "QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions" Proceedings of the National Academy of Sciences of the United States of America Vol. 112 Iss. 47 (2015) p. 14734 - 14739
Available at: http://works.bepress.com/paul-scott/31/