Analysis of phloem trajectory links tissue maturation to cell specialization.

Pawel Roszak, Jungok Heo, Bernhard Blob, Koichi Toyokura, Maria Angels De Luis Balaguer, Winnie Lau, Fiona K Hamey, Jacopo Cirrone, Xin Wang, Robertas Ursache, Hugo Tavares, Kevin Verstaen, Jos Wendrich, Charles W. Melnyk, Dennis Shasha, Sebastian Ahnert, Yvan Saeys, Bert De Rybel, Renze Heidstra, Ben ScheresAri Pekka Mähönen, Berthold Gottgens, Rosangela Sozzani, Kenneth David Birnbaum, Yrjö Helariutta

Research output: Contribution to journalArticleScientificpeer-review


The mechanisms that allow cells in the plant meristem to coordinate tissue-wide maturation gradients with specialized cell networks are critical for indeterminate growth. Here, we reconstructed the protophloem developmental trajectory of 19 cells from cell birth to terminal differentiation at single cell resolution in the Arabidopsis root. We found that cellular specification is mediated near the stem cell niche by PHLOEM EARLY DOF (PEAR) transcription factors. However, the PEAR dependent differentiation program is repressed by a broad gradient of PLETHORA (PLT) transcription factors, which directly inhibit PEARs' own direct target ALTERED PHLOEM DEVELOPMENT (APL). The dissipation of PLT gradient around 7 cells from the stem cell activates APL expression, and a subsequent transitional network that results in a "seesaw" pattern of mutual inhibition over developmental time. Together, we provide a mechanistic understanding of how morphogen-like maturation gradients interface with cell-type specific transcriptional regulators to stage cellular differentiation.
Original languageEnglish
JournalbioRxiv : the preprint server for biology
Publication statusUnpublished - 19 Jan 2021
MoE publication typeA1 Journal article-refereed

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