Hidden influence: How microbial stress responses shape plant natural selection

Soil microbial communities respond rapidly to stress, potentially leading to altered compositions in stressful environments and consequently impacting plant natural selection. Bolin and Lau investigated the influence of microbial responses to stress and persistent microbial legacy effects on plant selection. Chamaecrista fasciculata (partridge pea) plants were cultivated under stressful (salt, herbicide, or herbivory) or non-stressful conditions with microbes previously exposed to these environments. Microbial responses to stress counteracted the direct effects of stress on plant selection, thereby attenuating stress’s role as a selective agent. Additionally, microbial legacy effects of stress altered plant selection in non-stressful environments, indicating a prolonged impact beyond the stress period. These findings suggest that soil microbes may alter plant adaptation to stress, potentially reshaping the evolutionary trajectory of plant populations by reducing stress’s selective pressure. (Summary by Yueh Cho @YuehCho1984) New Phytologist. 10.1111/nph.19707.