How does long-term drought acclimation modify structure-function relationships? A quantitative approach to leaf phenotypic plasticity of barley

Abstract

Under drought conditions the growth and survival of a plant depend on its adaptive characteristics and acclimation ability. Adaptation refers to inherent morpho-physiological characters providing protection against water losses. Acclimation, however, is a special case of phenotypic plasticity: environment-dependent phenotypic expression resulting to a ‘new’ phenotype through drought-induced modulations in leaf morphology, anatomy and physiology. Given that phenotypic plasticity influences environmental tolerance, a multi-trait plasticity index could be of great importance. Therefore, we examined the acclimation processes of three different barley genotypes using a multi-trait plasticity assessment with emphasis on the leaf water economy-related traits. Our results showed that (i) the structure–function co-ordination during long-term drought acclimation follows the trade-off between carbon gain and water saving as well as the competition between investments in photosynthesis vs synthesis of protective compounds; (ii) the genotypes with smaller leaf area, narrower and denser veins, as well as smaller and denser stomata i.e. traits providing tolerance, exhibited less drastic adjustments under stress conditions, suggesting a trade-off between acclimation and tolerance-adaptation; and (iii) the slope values of a multi-trait ‘reaction norm’ based on regression analysis of PCA scores were indicative of the degree of plasticity for each genotype, providing an accurate representation of a complex set of data with single numeric results easily comparable.

Phenotypic Plasticity and Local Adaptation of Leaf Cuticular Waxes Favor Perennial Alpine Herbs under Climate Change

“…In response to different biotic and abiotic conditions, plant leaves will form various types and structures in order to grow and reproduce efficiently [ 47 ]. For example, leaf area has closest correlation with biomass, and leaf thickness is related to the environmental change [ 48 ]. In this study, the leaf length, width and thickness were positively correlated in Hongyuan, the leaf width and leaf thickness were positively correlated in Qilian, and the leaf wax characteristics showed low correlation with other leaf functional traits ( Supplementary Figure S3 ) and were generally separated in PCA analysis.…”

Plasticity in stomatal behavior across a gradient of water supply is consistent among field-grown maize inbred lines with varying stomatal patterning

“…But, complexity in the relationships between these traits means that structural-functional relationships controlling gs are still not easily predicted. For example, the relationship between gs and stomatal density can be positive (Li, Li, Li, & Zhang, 2017;Xu & Zhou, 2008), undetectable (Zhao, Sun, Kjelgren, & Liu, 2015), or negative (Bresta et al, 2018) across different species or pools of intraspecific variation. Likewise, the relationship between gs and stomatal complex area can be positive (Galmés et al, 2013;Li et al, 2017) undetectable (Xu & Zhou, 2008;Zhao et al, 2015) or dependent on the shape of the stomatal complex rather than its size (Xie et al 2021).…”

Drought tolerance of sugarcane propagules is improved when origin material faces water deficit

“…From a physiological perspective, plant acclimation is assumed as a functional change induced by an exogenous factor, such as water deficit [8]. Acclimation may result in improved plant response to stressors and then be related to stress memory, a way to store information of stressful events [3, 9, 10].…”

“…Acclimation may result in improved plant response to stressors and then be related to stress memory, a way to store information of stressful events [3, 9, 10]. The physiological acclimation permits plants to overcome resource limitation, improving tolerance while impairing plant growth [8]. Such plant acclimation can imprint signals that remain after perturbation and affect the future plant response to biotic or abiotic stresses.…”

“…One important requirement for retaining information about previous limiting conditions is that the stress-induced signals are still present when the stressor is no longer affecting plants [13]. There is reasonable evidence for assuming that plants can sense changes in the environment during growth and modify the phenotype of their progenies to be more adapted to growth conditions [8, 14]. The stress-induced signals can be transferred to subsequent generations by seeds and remain active through vegetative propagation [15].…”