DEFECTIVE ENDOSPERM-D1 (Dee-D1) is crucial for endosperm development in hexaploid wheat

Natalia Tikhenko,Andreas Houben,Stefan Ortleb,Twan Rutten,Dandan Wu,Manuela Nagel,Axel Himmelbach,Martin Mascher,Stefanie Sehmisch,Andreas Börner,Martin W Ganal,Marion S Röder,Lioudmilla Borisjuk,Ahmad M Alqudah

doi:10.1038/s42003-020-01509-9

Abstract

Hexaploid wheat (Triticum aestivum L.) is a natural allopolyploid and provides a usable model system to better understand the genetic mechanisms that underlie allopolyploid speciation through the hybrid genome doubling. Here we aimed to identify the contribution of chromosome 1D in the development and evolution of hexaploid wheat. We identified and mapped a novel DEFECTIVE ENDOSPERM–D1 (Dee-D1) locus on 1DL that is involved in the genetic control of endosperm development. The absence of Dee-D1 leads to non-viable grains in distant crosses and alters grain shape, which negatively affects grain number and thousand-grain weight. Dee-D1 can be classified as speciation locus with a positive effect on the function of genes which are involved in endosperm development in hybrid genomes. The presence of Dee-D1 is necessary for the normal development of endosperm, and thus play an important role in the evolution and improvement of grain yield in hexaploid wheat.

Highlights

Hexaploid wheat (Triticum aestivum L.) is a natural allopolyploid and provides a usable model system to better understand the genetic mechanisms that underlie allopolyploid speciation through the hybrid genome doubling
Each line was crossed with inbred marker line L6 or commercial rye populations to examine the presence of postzygotic barriers between hexaploid wheat and rye
Using a series of nullisomic-tetrasomic and chromosome 1D deletion lines of hexaploid wheat Chinese Spring (CS), we identified the exceptional role of chromosome 1D in endosperm formation both for bread wheat and in crosses with rye

Summary

Introduction

Hexaploid wheat (Triticum aestivum L.) is a natural allopolyploid and provides a usable model system to better understand the genetic mechanisms that underlie allopolyploid speciation through the hybrid genome doubling. The second event which took place about 8000 years ago led to the formation of the hexaploid wheat T. aestivum (BBAADD)[6,7]. In such polyploids, gene duplication alters the transcriptional landscape by providing additional flexibility to adapt and evolve new patterns of gene expression for homoeologous gene copies[4]. Nullisomic-tetrasomic and deletion lines are often used to identify the contribution of individual chromosomes and loci towards features that determine the productivity and adaptability of wheat[10]

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