Nuclear GSH import precedes coordinated cell cycle changes during regeneration.

Arabidopsis root tip regeneration requires cell division and cellular reprogramming. Here, we present new datasets that describe the cell cycle in Arabidopsis roots that maintain developmental context and cell-type resolution and provide an expanded set of cell cycle phase transcriptional markers. Using these data, we provide in vivo confirmation of a longstanding model in plants that glutathione (GSH) and reactive oxygen species (ROS) vary in a cell cycle dependent manner. We then demonstrate using long term time lapse imaging that cells in G1 phase undergo a transient peak of GSH prior to a tissue-wide coordinated entry into S phase. This coordinated S phase entry precedes a period of fast divisions, which we show appears to potentiate cellular reprogramming during regeneration. Taken together, this work demonstrates a role for GSH in coordinating cell cycle regulation and cellular reprogramming during regeneration.