Phenotypic variation and differentiated gene expression of Australian plants in response to declining rainfall

Abstract

Declining rainfall is projected to have negative impacts on the demographic performance of plant species. Little is known about the adaptive capacity of species to respond to drying climates, and whether adaptation can keep pace with climate change. In fire-prone ecosystems, episodic recruitment of perennial plant species in the first year post-fire imposes a specific selection environment, offering a unique opportunity to quantify the scope for adaptive response to climate change. We examined the growth of seedlings of four fire-killed species under control and drought conditions for seeds from populations established in years following fire receiving average-to-above-average winter rainfall, or well-below-average winter rainfall. We show that offspring of plants that had established under drought had more efficient water uptake, and/or stored more water per unit biomass, or developed denser leaves, and all maintained higher survival in simulated drought than did offspring of plants established in average annual rainfall years. Adaptive phenotypic responses were not consistent across all traits and species, while plants that had established under severe drought or established in years with average-to-above-average rainfall had an overall different physiological response when growing either with or without water constraints. Seedlings descended from plants established under severe drought also had elevated gene expression in key pathways relating to stress response. Our results demonstrate the capacity for rapid adaptation to climate change through phenotypic variation and regulation of gene expression. However, effective and rapid adaptation to climate change may vary among species depending on their capacity to maintain robust populations under multiple stresses.

Evolutionary and ecological functional genomics, from lab to the wild

“…In the EEFG framework, more studies are being undertaken that involve measurements of genome‐wide responses to the environment and their evolution (Liu et al ., ,; von Wettberg et al ., ). Studies have been able to leverage ‘omics’ technologies in the field to study the basis of local adaptation (Knight et al ., ; Gould et al ., ) and contribute to the understanding of changing environmental conditions and climate change (Fournier‐Level et al ., ; Hancock et al ., ; Nagano et al ., ; Plessis et al ., ; D'Agui et al ., ). Experiments that manipulate agents of selection in native field environments using pedigreed populations or GWAS panels also offer unique opportunities for detecting the genetic and environmental mechanisms that generate local adaptation (Wadgymar et al ., ).…”

Analysis of the transcriptome of the needles and bark of Pinus radiata induced by bark stripping and methyl jasmonate

“…An assessment of the genetic mechanisms that influence these defences will enhance our understanding of their evolution [ 1 ]. Although structural changes in DNA are the major source of genetic variation [ 2 , 3 ], the phenotypic outcomes of several traits can be linked to gene expression [ 4 – 8 ]. However, the genes and genetic pathways that underlie most phenotypes are still unknown [ 2 ].…”