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ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Physiology
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1490502

A novel root hair mutant, srh1, affects root hair elongation and reactive oxygen species levels in wheat

Provisionally accepted
Ian Tsang Ian Tsang 1,2*Pauline Thomelin Pauline Thomelin 1Lawrence Percival-Alwyn Lawrence Percival-Alwyn 2Eric Ober Eric Ober 1Darren M. Wells Darren M. Wells 2Jonathan A. Atkinson Jonathan A. Atkinson 2Stephen Rawsthorne Stephen Rawsthorne 3Fiona Leigh Fiona Leigh 2James Cockram James Cockram 1*
  • 1 National Institute of Agricultural Botany (NIAB), Cambridge, United Kingdom
  • 2 University of Nottingham, Nottingham, England, United Kingdom
  • 3 The Morley Agricultural Foundation, Morley, Norfolk, United Kingdom

The final, formatted version of the article will be published soon.

    Root hairs are single-celled projections on root surfaces, critical for water and nutrient uptake. Here, we describe the first short root hair mutant in wheat (Triticum aestivum L.), identified in a mutagenized population and termed here short root hair 1 (srh1 ). While the srh1 mutant is able to initiate root hair bulges, lack of subsequent extension results in very short root hairs. Due to its semi-dominant nature, heterozygous lines displayed intermediate root hair lengths compared to wild-type. Bulked segregant analysis in a BC1F3 segregating population genotyped via exome capture sequencing localized the genetic control of this mutant to a region on the long arm of chromosome 3A. Via RNA sequencing and bioinformatic analysis, we identified two promising candidate genes at the srh1 locus. The first is a respiratory burst oxidase homolog (RBOH) encoding gene TaNOX3-A, orthologous to RBOH genes controlling root hair elongation in rice (OSNOX3 ) and maize (ZmRTH5 ), that carries a missense mutation in a conserved region of the predicted protein. RBOHs are membrane bound proteins that produce reactive oxygen species (ROS) which trigger cell wall extensibility, allowing subsequent root hair elongation. Notably, reduced ROS levels were observed in srh1 root hair bulges compared to wild-type. The second candidate calreticulin-3 gene TaCRT3-A is located within the wider srh1 interval and its expression is significantly downregulated in srh1 root tissues. The identification of a major effect gene controlling wheat root hair morphology provides an entry point for future optimization of root hair architecture best suited to future agricultural environments.

    Keywords: Temperate cereal species, sustainable crop production, Root system architecture, exome capture, RNA sequencing (RNA-Seq), differential gene expression (DEG)

    Received: 03 Sep 2024; Accepted: 04 Oct 2024.

    Copyright: © 2024 Tsang, Thomelin, Percival-Alwyn, Ober, Wells, Atkinson, Rawsthorne, Leigh and Cockram. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Ian Tsang, National Institute of Agricultural Botany (NIAB), Cambridge, United Kingdom
    James Cockram, National Institute of Agricultural Botany (NIAB), Cambridge, United Kingdom

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