Plant Stem Cell Organization and Differentiation at Single-Cell Resolution

Plants maintain populations of pluripotent stem cells in shoot apical meristems (SAMs), which continuously produce new aboveground organs. We used single-cell RNA sequencing to achieve an unbiased characterization of the transcriptional landscape of the maize shoot stem-cell niche and its differentiating cellular descendants. Stem cells housed in the SAM tip are engaged in genome integrity maintenance and exhibit a low rate of cell division, consistent with their contributions to germline and somatic cell fates. Surprisingly, we find no evidence for a canonical stem cell organizing center subtending these cells. In addition, we use trajectory inference to trace the gene expression changes that accompany cell differentiation. These data provide a valuable scaffold on which to better dissect the genetic control of plant shoot morphogenesis.