Dioecious dynamics: How male and female poplars shape microbial networks under stress

Plants actively shape the microbial community in their rhizosphere to optimize nutrient acquisition and enhance resilience against environmental stresses. Interestingly, in dioecious plants, male and female individuals play distinct ecological roles and evolve different environmental adaptability. For instance, female poplar trees tend to allocate more resources to vegetative growth and reproduction, whereas male poplars prioritize defense and stress adaptation. However, the molecular mechanisms driving these differences remain largely unexplored. In a recent study, Yan and colleagues uncovered a fascinating aspect of this dimorphism under salinity stress. They observed that male poplars secrete higher levels of citric acid, which facilitates the recruitment of specific bacterial species in the rhizosphere. These bacteria form a keystone node in the microbial network, positively correlating with the male plants’ health index under stress. In contrast, female poplars showed a different interaction: fungal keystone nodes negatively correlated with their health index, suggesting harmful microbial associations. This study sheds light on the sexually dimorphic responses in plants and the intricate dynamics of plant-microbe interactions. It also highlights how poplars deploy a “cry for help” strategy to recruit beneficial microbes under stress conditions. (Summary by Ching Chan @ntnuchanlab) Plant, Cell & Environment 10.1111/pce.15350