Heritable heading time variation in wheat lines with the same number of Ppd-B1 gene copies

PLoS One. 2017 Aug 28;12(8):e0183745. doi: 10.1371/journal.pone.0183745. eCollection 2017.

Abstract

The ability of plants to identify an optimal flowering time is critical for ensuring the production of viable seeds. The main environmental factors that influence the flowering time include the ambient temperature and day length. In wheat, the ability to assess the day length is controlled by photoperiod (Ppd) genes. Due to its allohexaploid nature, bread wheat carries the following three Ppd-1 genes: Ppd-A1, Ppd-B1 and Ppd-D1. While photoperiod (in)sensitivity controlled by Ppd-A1 and Ppd-D1 is mainly determined by sequence changes in the promoter region, the impact of the Ppd-B1 alleles on the heading time has been linked to changes in the copy numbers (and possibly their methylation status) and sequence changes in the promoter region. Here, we report that plants with the same number of Ppd-B1 copies may have different heading times. Differences were observed among F7 lines derived from crossing two spring hexaploid wheat varieties. Several lines carrying three copies of Ppd-B1 headed 16 days later than other plants in the population with the same number of gene copies. This effect was associated with changes in the gene expression level and methylation of the Ppd-B1 gene.

MeSH terms

  • DNA Copy Number Variations
  • DNA Methylation
  • Genes, Plant*
  • Genetic Variation*
  • Photoperiod
  • Promoter Regions, Genetic
  • Quantitative Trait Loci
  • Triticum / genetics*
  • Triticum / physiology

Grants and funding

This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic (award LO1204 from the National Program of Sustainability I), Czech Science Foundation (grant no. P501-12-G090) and supported by Ministry of Agriculture of the Czech Republic, Project No. MZE ČR RO0417. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.