Nitrogen use efficiency is regulated by interacting proteins relevant to development in wheat

Abstract

SummaryWheat (Triticum aestivum) has low nitrogen use efficiency (NUE). The genetic mechanisms controlling NUE are unknown. Positional cloning of a major quantitative trait locus for N‐related agronomic traits showed that the vernalization gene TaVRN‐A1 was tightly linked with TaNUE1, the gene shown to influence NUE in wheat. Because of an Ala180/Val180 substitution, Ta VRN‐A1a and Ta VRN‐A1b proteins interact differentially with Ta ANR1, a protein encoded by a wheat orthologue of Arabidopsis nitrate regulated 1 (ANR1). The transcripts of both TaVRN‐A1 and TaANR1 were down‐regulated by nitrogen. TaANR1 was functionally characterized in TaANR1::RNAi transgenic wheat, and in a natural mutant with a 23‐bp deletion including 10‐bp at the 5′ end of intron 5 and 13‐bp of exon 6 in gDNA sequence in its gDNA sequence, which produced transcript that lacked the full 84‐bp exon 6. Both Ta ANR1 and Ta HOX1 bound to the Ala180/Val180 position of Ta VRN‐A1. Genetically incorporating favourable alleles from TaVRN‐A1, TaANR1 and TaHOX1 increased grain yield from 9.84% to 11.58% in the field. Molecular markers for allelic variation of the genes that regulate nitrogen can be used in breeding programmes aimed at improving NUE and yield in novel wheat cultivars.

Genome-Wide Association Study on Seminal and Nodal Roots of Wheat Under Different Growth Environments

“…A similar phenomenon was observed in FLOWERING LOCUS C ( FLC ), a MADS box gene encoding a transcription factor, that inhibits flowering. FLC not only regulates growth habits in spring but also affects flowering, root length, and nitrogen uptake ( Lei et al, 2018 ; Voss-Fels et al, 2018 ).…”

Biochemical and Genetic Approaches Improving Nitrogen Use Efficiency in Cereal Crops: A Review

“…QTL associated with NUE in rice were mapped using a recombinant inbred line (RIL) population on chromosome 6 (qNUEP-6; Shan et al, 2005) and on chromosome 9 (pnue9; Cho Y. I. et al, 2007). Thus, the research work carried out on cereal crops such as rice, maize, and wheat set a precedence for NUE research in other cereal crops such as barley Xu et al, 2014;Li P. et al, 2015;Lei et al, 2018;Mandolino et al, 2018). Cormier et al (2016) proposed that the identification of the genomic regions (QTL) associated with nitrogen response would enable more efficient cultivar selection.…”

TaANR1-TaBG1 and TaWabi5-TaNRT2s/NARs Link ABA Metabolism and Nitrate Acquisition in Wheat Roots

“…Arabidopsis nitrate regu-lated1 (ANR1), encoding a MADS-box transcription factor, plays an important role in the response to external nitrate supply in Arabidopsis (Zhang and Forde, 1998). Although its exact role in wheat is not clear, a recent study revealed TaANR1 can interact with TaNUE1, a protein encoded by the candidate gene of a major QTL for nitrogen-use efficiency (Lei et al, 2018). An expression profile assembled from RNA-sequencing data (Ramírez-González et al, 2018) and confirmed by RT-qPCR concluded that TaANR1 was mainly expressed in roots through the wheat life cycle (Supplemental Fig.…”

“…Additionally, the wheat mutants, Kronos 2467, 2985, and 4321, generated by Krasileva et al (2017), were procured via the Chinese distribution site, Shandong Agricultural University. The RNAi line of TaANR1 was generated in the cv CS background; the sense and antisense fragments were designed according to Lei et al (2018) and inserted into a ZmUbiquitin-promoter-containing vector, pTCK303 (Liu et al, 2014). Accession of Columbia (Col-0) was used as wild-type Arabidopsis (Arabidopsis thaliana), and all the mutant lines were in this background.…”