Single cell‐type transcriptome profiling reveals genes that promote nitrogen fixation in the infected and uninfected cells of legume nodules

作者：Longlong Wang, Yu Zhou, Runhui Li, Jianjun Liang, Tao Tian, Jie Ji, Runzhou Chen, Yumiao Zhou, Qiuling Fan, Guogui Ning, Robert M. Larkin, Manuel Becana, Deqiang Duanmu · 发表于：Plant Biotechnology Journal · 年份：2022 · DOI：10.1111/pbi.13778 · 被引用次数：37 · 研究领域：Legume Nitrogen Fixing Symbiosis、Plant nutrient uptake and metabolism、Nematode management and characterization studies

Excessive application of nitrogen fertilizers has inevitably resulted in environmental problems. The symbiotic nitrogen fixation (SNF) that occurs in the root nodules of leguminous plants provides a sustainable source of reduced nitrogen in agricultural ecosystems. More than 200 genes have been reported to regulate SNF, including rhizobial infection, nodule organogenesis and senescence (Roy et al., 2020). Mature nodules consist mainly of two cell types: infected cells (IC) that contain nitrogen-fixing bacteroids and uninfected cells (UC) that mediate active metabolism and nutrient transport. Although it is well known that SNF requires functional specialization, the specific genes responsible for transcriptional regulation and carbon/nitrogen metabolism and transport in IC and UC remain largely unexplored. Single-cell transcriptomics has emerged as a powerful technique for investigating spatiotemporal patterns of gene expression. The maximum cell diameter acceptable for these droplet-based methods is ~40 μm. An average size of IC from a legume nodule is typically 50–100 μm. We therefore manually separated reddish-brown IC and transparent UC (50–100 cells for each of these two cell types) from the mature nodules of Lotus japonicus at 4 weeks post-inoculation (wpi) with Mesorhizobium loti MAFF 303099 (Figure 1a,b; Appendix S1). Due to insurmountable technical difficulties, we were unable to separate IC into cells having various levels of nuclear DNA endoreduplication, or UC into...