For millions of years, underground fungi have lived in symbiosis with plant roots. Plants provide photosynthesized carbon, while fungi deliver water and nutrients. In order to do so, these organisms share space at the cellular scale: fungi stretch a network of tendrils called arbuscules into a plant's root cells, and both organisms rearrange their cells around this structure to facilitate sharing.
Recently, researchers have been able to study both sides of this interaction up close, using RNA sequencing to understand gene expression: one of the first cross-kingdom spatially-resolved transcriptomics studies to date. This paper appears as a cover article in Nature Plants.