Structural rearrangements in wheat (1BS)–rye (1RS) recombinant chromosomes affect gene dosage and root length. Issue 1 (18th January 2021)

• Record Type: Journal Article
• Authors: Gabay, Gilad; Zhang, Junli; Burguener, German Federico; Howell, Tyson; Wang, Hanchao; Fahima, Tzion; Lukaszewski, Adam; Moriconi, Jorge Ignacio; Santa Maria, Guillermo Esteban; Dubcovsky, Jorge
• Is Part Of: œplant genome. Volume 14:Issue 1(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-18
• Subjects: Plant genomes -- Periodicals; Plant genome mapping -- Periodicals; 572.862
• DOI: 10.1002/tpg2.20079
• Languages: English
• ISSNs: 1940-3372

Abstract

Abstract: Good understanding of the genes controlling root development is required to engineer root systems better adapted to different soil types. In wheat ( Triticum aestivum L.), the 1RS.1BL wheat–rye ( Secale cereale L.) translocation has been associated with improved drought tolerance and a large root system. However, an isogenic line carrying an interstitial segment from wheat chromosome arm 1BS in the distal region of the 1RS arm (1RS RW ) showed reduced grain yield and shorter roots both in the field and in hydroponic cultures relative to isogenic lines with the complete 1RS arm. In this study, we used exome capture to characterize 1RS RW and its parental lines T‐9 and 1B+40. We show that 1RS RW has a 7.0 Mb duplicated 1RS region and a 4.8 Mb 1BS insertion colinear with the 1RS duplication, resulting in triplicated genes. Lines homozygous for 1RS RW have short seminal roots, while lines heterozygous for this chromosome have roots of intermediate length. By contrast, near‐isogenic lines carrying only the 1BS distal region or the 1RS‐1BS duplication have long seminal roots similar to 1RS, suggesting a limited effect of the 1BS genes. These results suggest that the dosage of duplicated 1RS genes is critical for seminal root length. An induced deletion encompassing 38 orthologous wheat and rye duplicated genes restored root length and confirmed the importance of gene dosage in the short‐root phenotype. We explored the expression profiles and functional annotation of these genes and discuss their potential as candidate genes for the regulation of seminal root length in wheat. Core Ideas: Distal recombinant chromosomes between wheat 1BS and rye 1RS carry large, duplicated regions. An inversion between the distal regions of chromosomes 1BS and 1RS caused the duplications. Exome capture data defined the borders of duplicated and recombined regions. Changes in gene dosage were associated with changes in root development. A radiation deletion defined a region with 38 candidate genes for root length.