Comparative systems biology reveals allelic variation modulating Tocochromanol profiles in Barley (Hordeum vulgare L.)

PLoS One. 2014 May 12;9(5):e96276. doi: 10.1371/journal.pone.0096276. eCollection 2014.

Abstract

Tocochromanols are recognized for nutritional content, plant stress response, and seed longevity. Here we present a systems biological approach to characterize and develop predictive assays for genes affecting tocochromanol variation in barley. Major QTL, detected in three regions of a SNP linkage map, affected multiple tocochromanol forms. Candidate genes were identified through barley/rice orthology and sequenced in genotypes with disparate tocochromanol profiles. Gene-specific markers, designed based on observed polymorphism, mapped to the originating QTL, increasing R2 values at the respective loci. Polymorphism within promoter regions corresponded to motifs known to influence gene expression. Quantitative PCR analysis revealed a trend of increased expression in tissues grown at cold temperatures. These results demonstrate utility of a novel method for rapid gene identification and characterization, and provide a resource for efficient development of barley lines with improved tocochromanol profiles.

MeSH terms

  • Alleles*
  • Chromosome Mapping
  • Hordeum / genetics*
  • Polymorphism, Single Nucleotide / genetics
  • Quantitative Trait Loci / genetics
  • Systems Biology / methods*

Grants and funding

This work was supported by the United States Department of Agriculture - Agricultural Research Service CRIS project 301. SAS Institute Inc., provided support in the form of a salary for author KJM, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of the authors are articulated in the “Author Contributions” section.