Testing the association of relative growth rate and adaptation to climate across natural ecotypes of Arabidopsis

Abstract

Ecophysiologists have reported a range of relationships, including intrinsic trade-offs across and within species between plant relative growth rate in high resource conditions (RGR) vs adaptation to tolerate cold or arid climates, arising from trait-based mechanisms. Few studies have considered ecotypes within a species, in which the lack of a trade-off would contribute to a wide species range and resilience to climate change.For 15 ecotypes of Arabidopsis thaliana in a common garden we tested for associations between RGR vs adaptation to cold or dry native climates and assessed hypotheses for its mediation by 15 functional traits.Ecotypes native to warmer, drier climates had higher leaf density, leaf mass per area, root mass fraction, nitrogen per leaf area and carbon isotope ratio, and lower osmotic potential at full turgor. Relative growth rate was statistically independent of the climate of the ecotype native range and of individual functional traits.The decoupling of RGR and cold or drought adaptation in Arabidopsis is consistent with multiple stress resistance and avoidance mechanisms for ecotypic climate adaptation and would contribute to the species' wide geographic range and resilience as the climate changes.

Drought response strategies are coupled with leaf habit in 35 evergreen and deciduous oak (Quercus) species across a climatic gradient in the Americas

“…4), they did not have higher overall RGR (Tables 3, S1). Similar decoupling of growth rates and drought resistance adaptation patterns has been found in a Eurasian oak species (Ramírez‐Valiente et al ., 2020) and Arabidopsis ecotypes (Fletcher et al ., 2022).…”

The two sides of resistance–resilience relationship in both aboveground and belowground communities in the Eurasian steppe

“…Ecologists have reported a wide range of trade‐offs between different aspects of ecosystem function or stability, arising from life history (P. Wang et al ., 2021; Fletcher et al ., 2022). Trade‐offs between resistance and resilience have been demonstrated in previous studies based on drought conditions (Matos et al ., 2020; X. Li et al ., 2020; Piton et al ., 2021; Shen et al ., 2022).…”

A herbaceous species provides insights into drought-driven plant adaptation

“…Thonglim et al highlight that different modes of drought adaptation can be present within a single species. This raises the question of what it means to ‘tolerate’ drought, an interesting concept explored recently in relation to whole-plant growth in Arabidopsis ( Fletcher et al , 2022 ). Some naturally occurring genotypes (ecotypes) of this annual plant have been found to complete their life cycles rapidly, while other ecotypes are longer lived ( Mitchell-Olds and Schmitt, 2006 ; Fletcher et al , 2022 ).…”

“…This raises the question of what it means to ‘tolerate’ drought, an interesting concept explored recently in relation to whole-plant growth in Arabidopsis ( Fletcher et al , 2022 ). Some naturally occurring genotypes (ecotypes) of this annual plant have been found to complete their life cycles rapidly, while other ecotypes are longer lived ( Mitchell-Olds and Schmitt, 2006 ; Fletcher et al , 2022 ). Thonglim et al suggest that stem lignification may be higher in longer lived stems, which would be consistent with the idea that, as longer lived genotypes are more likely to experience stress, they may have greater need to invest in strategies for drought resistance.…”