Identification of candidate regulators of the response to early heat stress in climate-adapted wheat landraces via transcriptomic and co-expression network analyses

Liam J Barratt; Sara Franco Ortega; Andrea L Harper

doi:10.3389/fpls.2023.1252885

Identification of candidate regulators of the response to early heat stress in climate-adapted wheat landraces via transcriptomic and co-expression network analyses

Front Plant Sci. 2024 Jan 3:14:1252885. doi: 10.3389/fpls.2023.1252885. eCollection 2023.

Authors

Liam J Barratt¹, 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: Climate change is likely to lead to not only increased global temperatures but also a more variable climate where unseasonal periods of heat stress are more prevalent. This has been evidenced by the observation of spring-time temperatures approaching 40°C in some of the main spring-wheat producing countries, such as the USA, in recent years. With an optimum growth temperature of around 20°C, wheat is particularly prone to damage by heat stress. A warming climate with increasingly common fluctuations in temperature therefore threatens wheat crops and subsequently the lives and livelihoods of billions of people who depend on the crop for food. To futureproof wheat against a variable climate, a better understanding of the response to early heat stress is required.

Methods: Here, we utilised DESeq2 to identify 7,827 genes which were differentially expressed in wheat landraces after early heat stress exposure. Candidate hub genes, which may regulate the transcriptional response to early heat stress, were identified via weighted gene co-expression network analysis (WGCNA), and validated by qRT-PCR.

Results: Two of the most promising candidate hub genes (TraesCS3B02G409300 and TraesCS1B02G384900) may downregulate the expression of genes involved in the drought, salinity, and cold responses-genes which are unlikely to be required under heat stress-as well as photosynthesis genes and stress hormone signalling repressors, respectively. We also suggest a role for a poorly characterised sHSP hub gene (TraesCS4D02G212300), as an activator of the heat stress response, potentially inducing the expression of a vast suite of heat shock proteins and transcription factors known to play key roles in the heat stress response.

Discussion: The present work represents an exploratory examination of the heat-induced transcriptional change in wheat landrace seedlings and identifies several candidate hub genes which may act as regulators of this response and, thus, may be targets for breeders in the production of thermotolerant wheat varieties.

Keywords: Triticum aestivum; heat; hub gene; landrace; network analysis; transcriptomics.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by UK Biotechnology and Biological Sciences Research Council White Rose Doctorial Training Partnerships (DTP) in Mechanistic Biology (BB/M011151/1). 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, CIMMYT, Mexico, and the Crop Research Institute, Czechia, for providing additional germplasm.