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.
Plants are often simultaneousl