Translatome analyses capture of opposing tissuespecific brassinosteroid signals orchestrating root meristem differentiation

Kristina Vragović, Ayala Selaa, Lilach Friedlander-Shani, Yulia Fridman, Yael Hacham, Neta Holland, Elizabeth Bartom, Todd C. Mockler, Sigal Savaldi-Goldstein*

*Corresponding author for this work

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

The mechanisms ensuring balanced growth remain a critical question in developmental biology. In plants, this balance relies on spatiotemporal integration of hormonal signaling pathways, but the understanding of the precise contribution of each hormone is just beginning to take form. Brassinosteroid (BR) hormone is shown here to have opposing effects on root meristem size, depending on its site of action. BR is demonstrated to both delay and promote onset of stem cell daughter differentiation, when acting in the outer tissue of the root meristem, the epidermis, and the innermost tissue, the stele, respectively. To understand the molecular basis of this phenomenon, a comprehensive spatiotemporal translatome mapping of Arabidopsis roots was performed. Analyses of wild type and mutants featuring different distributions of BR revealed autonomous, tissuespecific gene responses to BR, implying its contrasting tissue-dependent impact on growth. BR-induced genes were primarily detected in epidermal cells of the basal meristem zone and were enriched by auxinrelated genes. In contrast, repressed BR genes prevailed in the stele of the apical meristem zone. Furthermore, auxin was found to mediate the growth-promoting impact of BR signaling originating in the epidermis, whereas BR signaling in the stele buffered this effect. We propose that context-specific BR activity and responses are oppositely interpreted at the organ level, ensuring coherent growth.

Original languageEnglish (US)
Pages (from-to)923-928
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume112
Issue number3
DOIs
StatePublished - Jan 20 2015

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Keywords

  • Auxin
  • BRI1
  • Brassinosteroids
  • Intertissue communication
  • Root meristem

ASJC Scopus subject areas

  • General

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