Leaf senescence mapped through Arabidopsis single-nucleus RNA-Seq atlas

As both the power and accessibility of single-cell RNA sequencing increases, more reference datasets have become available, documenting the transcriptome within a variety of model plants. While invaluable resources that have pushed science forward, these datasets are often limited to single tissues or few timepoints. Additionally, they lack information on tissues like senescing leaves, flowers, and fruits because it is more difficult to isolate single-cell protoplasts from these tissues. To have a fuller understanding of the interconnected spatiotemporal relationships throughout development, Guo et al. have constructed an atlas of Arabidopsis single-nucleus RNA sequencing transcriptomic information across 20 tissues at multiple developmental stages from vegetative growth to reproductive growth, identifying 38 cell types. This atlas focuses on characterizing leaf senescence and nutrient allocation, two topics neglected by previous methods. Key regulators of senescence were identified by the atlas and developed into a quantitative leaf aging index that can assess age state of leaf cells from single-cell transcriptomic information. 6,591 senescence-associated genes and 1,875 youth-associated genes were identified, and aging hub genes were determined by co-expression network analysis. The atlas was also applied to nutrient allocation, mapping the carbon and nitrogen transporters involved in source-sink dynamics. In the future, this dataset could be used to characterize gene interactions between the key regulator genes and associated signaling pathways, integrating the dynamics of senescence and nutrient source-sink allocation.  (Summary by Elise Krespan) Cell  https://doi.org/10.1016/j.cell.2025.03.024