[植物生理] 小麥的胚胎發育與轉錄基因組。 20191108 The Plant Cell

Plasmodesmata
Nov 8, 2019
2 min read

The Transcriptional Landscape of Polyploid Wheats and their Diploid Ancestors during Embryogenesis and Grain Development

Daoquan Xiang, Teagen D. Quilichini, Ziying Liu, Peng Gao, Youlian Pan, Qiang Li, Kirby T. Nilsen, Prakash Venglat, Eddi Esteban, Asher Pasha, Yejun Wang, Rui Wen, Zhongjuan Zhang, Zhaodong Hao, Edwin Wang, Yangdou Wei, Richard Cuthbert, Leon Kochian, Andrew Sharpe, Nicholas Provart, Dolf Weijers, C. Stewart Gillmor, Curtis Pozniak, Raju Datla

ABSTRACT

Modern wheat production comes from two polyploid species, Triticum (T.) aestivum and T. turgidum (var. durum), which putatively arose from diploid ancestors T. urartu, Aegilops (Ae.) speltoides, and Ae. tauschii. How gene expression during embryogenesis and grain development in wheats has been shaped by the differing contributions of diploid genomes through hybridization, polyploidization, and breeding selection is not well understood. The present study describes the global landscape of gene activities during wheat embryogenesis and grain development. Using comprehensive transcriptomic analyses of two wheat cultivars and three diploid grasses, we investigated gene expression at seven stages of embryo development, two endosperm stages, and one pericarp stage. We identified transcriptional signatures and developmental similarities and differences among the five species, revealing the evolutionary divergence of gene expression programs and the contributions of A, B, and D sub-genomes to grain development in polyploid wheats. The characterization of embryonic transcriptional programming in hexaploid wheat, tetraploid wheat, and diploid grass species provides insight into the landscape of gene expression in modern wheat and its ancestral species. This study presents a framework for understanding the evolution of domesticated wheat and the selective pressures placed on grain production, with important implications for future performance and yield improvements.

多倍體小麥與其二倍體祖先在胚胎發育與種子發育時的轉錄基因組總覽

摘要

現今的小麥是經由兩個多倍體的父母本Triticum (T.) aestivum 以及T. turgidum （var. durum）經由雜交而來。這兩個父母本的來源，可能是二倍體的T. urartu, Aegilops (Ae.) speltoides 和 Ae. tauschii。在胚胎發育與種子發育時期基因的表現，是如何經由不同的多倍體基因體的雜交、多倍體化以及育種選擇所影響的，仍然不是很清楚。這個研究描述了在小麥胚胎發育與種子發育時期，整體基因的轉錄活動圖譜。利用全面地轉錄基因組分析來研究兩個小麥的培育品種以及三種二倍體禾本科植物，我們探究了七個胚胎發育階段、兩個胚乳發育階段以及果皮發育階段的基因表現。我們在這五個品種中，鑑定出了轉錄基因的特徵以及發育上的相似以及相異處，並且研究了A、B以及D的子基因體，在多倍體小麥中，對於種子發育的貢獻。五倍體、四倍體以及二倍體小麥中轉錄程式的特徵，提供了一窺在現今的小麥中基因表現風貌的基礎。這個研究呈現了暸解馴化小麥的演進以及對於種子生產所施加的篩選壓力的基礎架構，並且對於未來增進產量與性能有著重要的意涵在內。