Transcriptome Responses to Combinations of Stresses in Arabidopsis    

Abstract

Biotic and abiotic stresses limit agricultural yields, and plants are often simultaneously exposed to multiple stresses. Combinations of stresses such as heat and drought or cold and high light intensity have profound effects on crop performance and yields. Thus, delineation of the regulatory networks and metabolic pathways responding to single and multiple concurrent stresses is required for breeding and engineering crop stress tolerance. Many studies have described transcriptome changes in response to single stresses. However, exposure of plants to a combination of stress factors may require agonistic or antagonistic responses or responses potentially unrelated to responses to the corresponding single stresses. To analyze such responses, we initially compared transcriptome changes in 10 Arabidopsis (Arabidopsis thaliana) ecotypes using cold, heat, high-light, salt, and flagellin treatments as single stress factors as well as their double combinations. This revealed that some 61% of the transcriptome changes in response to double stresses were not predictable from the responses to single stress treatments. It also showed that plants prioritized between potentially antagonistic responses for only 5% to 10% of the responding transcripts. This indicates that plants have evolved to cope with combinations of stresses and, therefore, may be bred to endure them. In addition, using a subset of this data from the Columbia and Landsberg erecta ecotypes, we have delineated coexpression network modules responding to single and combined stresses.

What Is Stress? Dose-Response Effects in Commonly Used in Vitro Stress Assays

“…Based on the data presented here for osmotic stress, we postulate that there may not be a simple linear response in which the expression of individual genes correlates with the stress level but that different stress levels to some extent switch on entirely different transcriptomes. This is similar to what is seen when different stresses are combined, resulting in transcriptome changes that are different from those induced by single stresses (Rizhsky et al, 2004;Rasmussen et al, 2013). Accordingly, there is no correlation between enhanced survival under severe stress conditions and improved growth under mild stress conditions, because different mechanisms are involved (Skirycz et al, 2011b).…”

Phosphate-dependent root system architecture responses to salt stress

“…S1), but we cannot exclude the possibility of the involvement of the same genetic factors. Complex regulation of responses to multiple stresses also has been shown for RSA modulations by other nutrient combinations as well as for multiple abiotic and biotic stresses at the transcriptional level (Rasmussen et al, 2013;Kellermeier et al, 2014). The validation and further characterization of identified candidates will contribute to understanding mechanisms of multiple stress integration for MR and LRs.…”

“…In their natural habitats, plants are exposed to multiple stresses, and responses to them in general differ from the responses to single stresses or a sum of the individual stresses. Transcriptomics and proteomics studies were the first to reveal the complexity of the response to multiple stresses (Rizhsky et al, 2002;Koussevitzky et al, 2008;Rasmussen et al, 2013;Rivero et al, 2014;Sewelam et al, 2014). Besides the transcriptional responses to multiple stresses, their physiological consequences have been studied only recently.…”

Inhibition of the oxidative stress response by heat stress inCaenorhabditis elegans

“…Less studied are potential interactions between the molecular stress responses. Combinations of stressors can radically modulate the expression of various stress-responsive genes relative to single-stress exposures (Rasmussen et al, 2013), raising the possibility that the altered expression of stress-responsive genes during combined stress is maladaptive, contributing to synergistic effects that reduce organism growth, performance and survival.…”