Transcriptomes of synthetic wheat allohexaploid and related natural species

Bread wheat is an allohexaploid species that emerged <10,000 years ago from a hybridization between Aegilops tauschii and durum wheat. Polyploidization is associated with suite of genomic changes that include transcriptional reprogramming of a fraction of genes. On the other hand, established polyploids exhibit unbalanced expression for a large part of homoeologous genes (corresponding orthologs originating from the parental species). This project explores the extent of transcriptomic changes in nascent wheat allohexaploids in developing endosperm and mature leaves, across different synthetic genotypes, reciprocal cross directions and consecutive generations. It also aims to investigate changes in the transcription of transposable elements, and the relationship between differential expression and homoeolog bias.

普通小麦（Bread wheat）是一种异源六倍体物种（allohexaploid species），于距今不足1万年前由节节麦（Aegilops tauschii）与硬粒小麦（durum wheat）杂交形成。多倍体化（polyploidization）过程伴随一系列基因组变化，其中涵盖部分基因的转录重编程（transcriptional reprogramming）。另一方面，已稳定的多倍体在很大一部分部分同源基因（homoeologous genes，即源自亲本物种的对应直向同源基因（orthologs））上表现出表达失衡现象。本项目旨在探究不同合成基因型、正反交方向及连续世代背景下，新生异源六倍体小麦在发育胚乳（developing endosperm）与成熟叶片（mature leaves）中的转录组变化程度；同时还将调查转座元件（transposable elements）的转录变化情况，以及差异表达（differential expression）与部分同源基因表达偏向性（homoeolog bias）之间的关联。