Analysis of Gene Expression in Resynthesized Brassica Napus Allotetraploids: Transcriptional Changes Do Not Explain Differential Protein Regulation

New Phytol. 2010 Apr;186(1):216-27. doi: 10.1111/j.1469-8137.2009.03139.x. Epub 2010 Jan 19.

Abstract

Polyploidy, or whole genome duplication, is a major evolutionary process that has shaped eukaryotic genomes, notably those of flowering plants. The mechanisms underlying the regulation of, and sharing of functions between, the duplicated genes originating from polyploidy events, which lead to novel phenotypes, remain to be elucidated. A previous comparative proteomic study identified 360 proteins that were differentially regulated between the diploid Brassica progenitors and their synthetic allotetraploid derivatives. For 102 of these proteins, using the same resynthesized Brassica napus allotetraploids, we assayed the accumulation of the transcripts of the corresponding genes. We compared transcript levels quantified in the synthetic allotetraploids with the mid-parent expression values. Although all of the genes surveyed encoded nonadditive proteins, we found that two-thirds of them had additive transcript levels, indicating that most of the differential protein regulation is not explained by transcriptional changes. Our data suggest that differential protein regulation is mainly governed by post-transcriptional modifications. Summarizing available data from transcriptomic studies of other synthetic allopolyploid models, we describe the general trends of transcript regulation in an allopolyploid genome and discuss putative underlying molecular mechanisms, with particular emphasis on the small RNA pathway for the post-transcriptional control of gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brassica napus / genetics*
  • Gene Expression Regulation, Plant*
  • Genes, Plant / genetics
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Polyploidy*
  • Proteomics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic*

Substances

  • Plant Proteins
  • RNA, Messenger