期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：51
页码：32750-32756
DOI：10.1073/pnas.2018565117
出版社：The National Academy of Sciences of the United States of America
摘要：Cell division is often regulated by extracellular signaling networks to ensure correct patterning during development. In Arabidopsis , the SHORT-ROOT (SHR)/SCARECROW (SCR) transcription factor dimer activates CYCLIND6 ; 1 ( CYCD6;1 ) to drive formative divisions during root ground tissue development. Here, we show plasma-membrane-localized BARELY ANY MERISTEM1/2 (BAM1/2) family receptor kinases are required for SHR -dependent formative divisions and CYCD6;1 expression, but not SHR -dependent ground tissue specification. Root-enriched CLE ligands bind the BAM1 extracellular domain and are necessary and sufficient to activate SHR -mediated divisions and CYCD6;1 expression. Correspondingly, BAM-CLE signaling contributes to the restriction of formative divisions to the distal root region. Additionally, genetic analysis reveals that BAM-CLE and SHR converge to regulate additional cell divisions outside of the ground tissues. Our work identifies an extracellular signaling pathway regulating formative root divisions and provides a framework to explore this pathway in patterning and evolution.
