Marchantia polymorpha gene expression atlas reveals the hierarchy of abiotic stress responses and conservation of diurnal gene expression

Abiotic stress has a dramatic impact on ecosystems and the yield of crops, and global warming will likely result in more frequent and intense stresses. However, due to the complexity of the underlying signalling pathways and the fact that stresses often occur in combinations in nature, our knowledge of how plants acclimatize to abiotic stress is still lacking. Here, we used a plant with minimal regulatory network redundancy, Marchantia polymorpha, to study how seven abiotic stresses alone and in combination affect the phenotype, gene expression, and activity of biological pathways. Worryingly, we see no evidence of conservation of gene expression to abiotic stress between model organisms, suggesting that each species develops unique strategies to cope with abiotic stress. Interestingly, we observed that certain stresses are able to suppress others, while specific combinations can elucidate novel transcriptomic responses. Finally, we provide two online databases to study abiotic stress responses and diurnal gene expression data in Marchantia.