The ability to regenerate an entire meristem is a remarkable feature of development at which the plant excels. For one, remnant cells that reorganize into replacement tissues have lost the continuity of development from earlier embryonic and post-embryonic organogenesis. In addition, the remnant tissue that regenerates a new meristem can have an unpredictable shape and tissue confirmation. How does tissue “measure” and pattern an entirely new meristem with seemingly little consistent information from the remnant tissue? This feat of self-organization is a pre-occupation of the lab. We have been using single-cell RNA-seq as a proxy for dynamic cell states combined with imaging to watch tissues assemble and domains reform after excising the root meristem. We have a partial model of hormone domain assembly involving auxin and cytokinin antagonism that re-establishes the proximo-distal axis. However, many of the signals and much of the instructive patterning information remains a mystery. I will detail some of our recent progress in using new techniques to uncover the signals that help organize a new root meristem during regeneration.
