Abstract
Crops are often subjected to periods of drought stress during their life cycle. However, how stress response mechanisms contribute to the crosstalk between stress signaling pathways and developmental signaling pathways is still unknown. We built a gene co-expression network from a spatio-temporal transcriptomic map of the drought stress response in maize (Zea mays), profiled from three tissues and four developmental stages and characterized hub genes associated with duplication events, selection, and regulatory networks. Co-expression analysis grouped drought-response genes into ten modules, covering 844 highly connected genes (hub genes). Of these, 15.4% hub genes had diverged by whole-genome duplication events and 2.5% might then have been selected during natural domestication and artificial improvement processes, successively. We identified key transcription factor hubs in a transcriptional regulatory network, which may function as a crosstalk mechanism between drought stress and developmental signalling pathways in maize. Understanding the evolutionary biases that have evolved to enhance drought adaptation lays the foundation for further dissection of crosstalk between stress signalling pathways and developmental signalling pathways in maize, towards molecular design of new cultivars with desirable yield and greater stress tolerance.
Highlights
Drought or water deficiency is one of the most serious environmental stresses affecting plant growth and development and crop yield and productivity[1, 2]
We studied drought-stress-related genes identified by previous population genetics research[28], with the goal of learning more about evolutionary selection for drought adaptation, and to determine whether there is any evidence that these genes have biased evolution and, if so, whether that bias varies with the progression of selection
Using the commonly used criteria of defining an ‘expressed’ gene (FPKM ≥ 1), we found that 19,293–23,053 genes were expressed under the experimental conditions analysed (Fig. S1)
Summary
Drought or water deficiency is one of the most serious environmental stresses affecting plant growth and development and crop yield and productivity[1, 2]. Drought tolerance is a complex quantitative trait that is potentially correlated with other developmental traits, such as plant height, leaf area, stem diameter, and plant biomass[10] These traits are generally quantitative, and each is controlled by multiple quantitative trait loci (QTLs) with relatively small individual effects on the corresponding traits, making them difficult to dissect by classical genetics approaches[11]. Because of their agricultural importance, drought-stress-related mechanisms in maize have been explored using high-throughput experimental techniques, including genome-wide association studies (GWAS)[12,13,14,15,16,17] and next-generation sequencing (NGS)[18, 19]. We studied drought-stress-related genes identified by previous population genetics research[28], with the goal of learning more about evolutionary selection for drought adaptation, and to determine whether there is any evidence that these genes have biased evolution and, if so, whether that bias varies with the progression of selection
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
