Abstract
The impact of reduced rainfall and increased temperatures forecasted by climate change models on plant communities will depend on the capacity of plant species to acclimate and adapt to new environmental conditions. The acclimation process is mainly driven by epigenetic regulation, including structural and chemical modifications on the genome that do not affect the nucleotide sequence. In plants, one of the best-known epigenetic mechanisms is cytosine-methylation. We evaluated the impact of 30% reduced rainfall (hereafter “drought” treatment; D), 3 °C increased air temperature (“warming”; W), and the combination of D and W (WD) on the phenotypic and epigenetic variability of Hordeum murinum subsp. leporinum L., a grass species of high relevance in Mediterranean agroforestry systems. A full factorial experiment was set up in a savannah-like ecosystem located in southwestern Spain. H. murinum exhibited a large phenotypic plasticity in response to climatic conditions. Plants subjected to warmer conditions (i.e., W and WD treatments) flowered earlier, and those subjected to combined stress (WD) showed a higher investment in leaf area per unit of leaf mass (i.e., higher SLA) and produced heavier seeds. Our results also indicated that both the level and patterns of methylation varied substantially with the climatic treatments, with the combination of D and W inducing a clearly different epigenetic response compared to that promoted by D and W separately. The main conclusion achieved in this work suggests a potential role of epigenetic regulation of gene expression for the maintenance of homoeostasis and functional stability under future climate change scenarios.
Highlights
Of the eight phenotypic traits considered in this study, four exhibited significant differences among treatments (p value < 0.05): Leaf Size (LS), Specific Leaf Area (SLA), Fig. 1 Changes in some key phenotypic traits as a function of the climatic treatment. a Leaf size; b Specific Leaf Area; c Flowering onset and; d Seed mass. p p-value from overall effect test
Regarding reproductive phenology, warming accelerated the onset of flowering in about ten days compared with those plants growing under control conditions
Significant differences in seed mass were found among treatments, with warming and drought (WD) plants producing seeds of higher weight, especially when compared to plants subjected to drought (Fig. 1d)
Summary
Plants subjected to greater water/nutrient limitations usually exhibit a suite of trait values associated to efficient resource conservation use (e.g., plants with small-sized and high-density leaves) (Chapin et al 1993; Wright et al 2004), which increases competitive abilities under resource-limiting conditions. This strategy contrasts with that displayed by plants inhabiting moist and fertile sites, with opposite trait values related to a rapid return on investment. Under non-limiting conditions of soil water and nutrient availability, an increase in air temperature could result in thinner leaves with higher specific leaf area that favour plant carbon uptake and growth (Poorter et al 2009; Epigenetic responses of hare barley (Hordeum murinum subsp. leporinum) to climate change: an
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
