Transcriptomic and co-expression network analyses on diverse wheat landraces identifies candidate master regulators of the response to early drought

Liam J Barratt; Isaac J Reynolds; Sara Franco Ortega; Andrea L Harper

doi:10.3389/fpls.2023.1212559

Transcriptomic and co-expression network analyses on diverse wheat landraces identifies candidate master regulators of the response to early drought

Front Plant Sci. 2023 Jun 23:14:1212559. doi: 10.3389/fpls.2023.1212559. eCollection 2023.

Authors

Liam J Barratt¹, Isaac J Reynolds¹, Sara Franco Ortega¹, Andrea L Harper¹

Affiliation

¹ Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, York, United Kingdom.

Abstract

Introduction: Over four billion people around the world rely on bread wheat (Triticum aestivum L.) as a major constituent of their diet. The changing climate, however, threatens the food security of these people, with periods of intense drought stress already causing widespread wheat yield losses. Much of the research into the wheat drought response has centred on the response to drought events later in development, during anthesis or grain filling. But as the timing of periods of drought stress become increasingly unpredictable, a more complete understanding of the response to drought during early development is also needed.

Methods: Here, we utilized the YoGI landrace panel to identify 10,199 genes which were differentially expressed under early drought stress, before weighted gene co-expression network analysis (WGCNA) was used to construct a co-expression network and identify hub genes in modules particularly associated with the early drought response.

Results: Of these hub genes, two stood out as novel candidate master regulators of the early drought response - one as an activator (TaDHN4-D1; TraesCS5D02G379200) and the other as a repressor (uncharacterised gene; TraesCS3D02G361500).

Discussion: As well as appearing to coordinate the transcriptional early drought response, we propose that these hub genes may be able to regulate the physiological early drought response due to potential control over the expression of members of gene families well-known for their involvement in the drought response in many plant species, namely dehydrins and aquaporins, as well as other genes seemingly involved in key processes such as, stomatal opening, stomatal closing, stomatal morphogenesis and stress hormone signalling.

Keywords: drought; hub gene; landrace; network analysis; transcriptomics; triticum aestivum (bread wheat).

Grants and funding

This work was supported by UK Biotechnology and Biological Sciences Research Council White Rose Doctorial Training Partnerships (DTP) in Mechanistic Biology (BB/M011151/1, BB/T007222/1). The authors thank the Germplasm Resource Unit at John Innes Centre, UK (Grant number BBS/E/J/000PR8000) for providing germplasm and sharing the genotype and genetic map information, as well as CIMMYT, Mexico, and the Crop Research Institute, Czechia for providing additional germplasm.