Effects of sublethal single, simultaneous and sequential abiotic stresses on phenotypic traits of Arabidopsis thaliana

Abstract

Plant responses to abiotic stresses are complex and dynamic, and involve changes in different traits, either as the direct consequence of the stress, or as an active acclimatory response. Abiotic stresses frequently occur simultaneously or in succession, rather than in isolation. Despite this, most studies have focused on a single stress and single or few plant traits. To address this gap, our study comprehensively and categorically quantified the individual and combined effects of three major abiotic stresses associated with climate change (flooding, progressive drought and high temperature) on 12 phenotypic traits related to morphology, development, growth and fitness, at different developmental stages in four Arabidopsis thaliana accessions. Combined sublethal stresses were applied either simultaneously (high temperature and drought) or sequentially (flooding followed by drought). In total, we analysed the phenotypic responses of 1782 individuals across these stresses and different developmental stages. Overall, abiotic stresses and their combinations resulted in distinct patterns of effects across the traits analysed, with both quantitative and qualitative differences across accessions. Stress combinations had additive effects on some traits, whereas clear positive and negative interactions were observed for other traits: 9 out of 12 traits for high temperature and drought, 6 out of 12 traits for post-submergence and drought showed significant interactions. In many cases where the stresses interacted, the strength of interactions varied across accessions. Hence, our results indicated a general pattern of response in most phenotypic traits to the different stresses and stress combinations, but it also indicated a natural genetic variation in the strength of these responses. This includes novel results regarding the lack of a response to drought after submergence and a decoupling between leaf number and flowering time after submergence. Overall, our study provides a rich characterization of trait responses of Arabidopsis plants to sublethal abiotic stresses at the phenotypic level and can serve as starting point for further in-depth physiological research and plant modelling efforts.

Impact of individual, combined and sequential stress on photosynthesis machinery in rice (Oryza sativa L)

“…On the other hand, the s tress response in plants is always accompanied by reprogramming of the metabolism from the photo‐assimilatory to the survival pathway (Chojak‐Kozniewska et al, 2017). Although previous studies have shown detrimental effects of combined stress combinations in crops such as rice (Kadam et al, 2015; Morlaes et al, 2022; Yadav et al, 2022), yet the response of rice to sequential post‐submergence drought stress is unique. For example, submergence regulator SUB1A cross‐talk across submergence and drought stress in rice where SUB1A has been shown to augment ABA responsiveness and ROS scavenging enzymes, hence working efficiently across submergence and drought stress at the vegetative stage (Fukao et al, 2011).…”

“…On the other hand, a substantial impact of submergence and post‐submergence drought stress has been observed on gas exchange traits and photosynthesis machinery in this genotype (Figure 4). Morales et al (2022) have shown that drastic reduction in light intensity, stomatal conductance, and photosynthesis resulted in severe energy and carbon imbalance in Arabidopsis under submergence stress and post‐submergence drought stress. Yeung et al (2018) further demonstrated how the post‐submergence phase is associated with new stressors.…”

“…Morales et al (2022) have shown that drastic reduction in light intensity, stomatal conductance, and photosynthesis resulted in severe energy and carbon imbalance in Arabidopsis under submergence stress and post-submergence drought stress Yeung et al (2018). further demonstrated how the postsubmergence phase is associated with new stressors.…”

‘Against all floods’: plant adaptation to flooding stress and combined abiotic stresses

“…Another consideration is that two stresses, which individually cause opposite adaptations, occur simultaneously (Figure 1b). Collision of such opposing pathways may lead to intermediate phenotypes that might or might not be beneficial for tolerance (Morales et al., 2022). Contrastingly, it is possible that one stressor is dominant and overwrites the response of a combined secondary stressor (Morales et al., 2022; Sewelam et al., 2020).…”

“…Collision of such opposing pathways may lead to intermediate phenotypes that might or might not be beneficial for tolerance (Morales et al., 2022). Contrastingly, it is possible that one stressor is dominant and overwrites the response of a combined secondary stressor (Morales et al., 2022; Sewelam et al., 2020). However, the number and complexity degree of possible combinations, especially when more than two stressors occur, makes it difficult to predict plant reactions to multifactorial stress combinations.…”