Journal Article

Transcriptome asymmetry in synthetic and natural allotetraploid wheats, revealed by RNA‐sequencing

Zhang, Huakun, Zhang, Zhibin, Li, Linfeng, Wang, Xutong, Li, Yaling, Liu, Bao

2016

Overview

Allopolyploidization has occurred frequently within the Triticum–Aegilops complex which provides a suitable system to investigate how allopolyploidization shapes the expression patterns of duplicated homeologs. We have conducted transcriptome‐profiling of leaves and young inflorescences in wild and domesticated tetraploid wheats, Triticum turgidum ssp. dicoccoides (BBAA) and ssp. durum (BBAA), an extracted tetraploid (BBAA), and a synthetic tetraploid (SˡSˡAA) wheat together with its diploid parents, Aegilops longissima (SˡSˡ) and Triticum urartu (AA). The two diploid species showed tissue‐specific differences in genome‐wide ortholog expression, which plays an important role in transcriptome shock‐mediated homeolog expression rewiring and hence transcriptome asymmetry in the synthetic tetraploid. Further changes of homeolog expression apparently occurred in natural tetraploid wheats, which led to novel transcriptome asymmetry between the two subgenomes. In particular, our results showed that extremely biased homeolog expression can occur rapidly upon the allotetraploidzation and this trend is further enhanced in the course of domestication and evolution of polyploid wheats. Our results suggest that allopolyploidization is accompanied by distinct phases of homeolog expression changes, with parental legacy playing major roles in the immediate rewiring of homeolog expression upon allopolyploidization, while evolution and domestication under allotetraploidy drive further homeolog‐expression changes toward re‐established subgenome expression asymmetry.

• Publisher: Academic Press,New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: Aegilops longissima / allopolyploidization / Biological Evolution / Diploidy / Domestication / durum wheat / evolution / Gene Expression Regulation, Plant / Gene Regulatory Networks / Genes, Plant / homeolog expression bias / Inflorescence - genetics / inflorescences / leaves / parents / Plant Leaves - genetics / RNA, Messenger - genetics / RNA, Messenger - metabolism / Seeds - genetics / Sequence Analysis, RNA - methods / Tetraploidy / transcriptome / Transcriptome - genetics / transcriptome asymmetry / Triticum / Triticum - genetics / Triticum aestivum / Triticum turgidum / Triticum turgidum subsp. dicoccoides / Triticum turgidum subsp. durum / Triticum urartu / Triticum–Aegilops complex / wheat