학술논문
The transcription factor AtMYB12 is part of a feedback loop regulating cell division orientation in the root meristem vasculature.
Document Type
Article
Author
Source
Subject
*CELL division
*TRANSCRIPTION factors
*GENE regulatory networks
*MERISTEMS
*BLOOD vessels
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Language
ISSN
0022-0957
Abstract
Transcriptional networks are crucial to integrate various internal and external signals into optimal responses during plant growth and development. In Arabidopsis thaliana , primary root vasculature patterning and proliferation are controlled by a network centred around the basic Helix-Loop-Helix transcription factor complex, formed by TARGET OF MONOPTEROS 5 (TMO5) and LONESOME HIGHWAY (LHW), which control cell proliferation and division orientation by modulating the cytokinin response and other downstream factors. Despite recent progress, many aspects of the TMO5/LHW pathway are not fully understood. In particular, the upstream regulators of TMO5/LHW activity remain unknown. Here, using a forward genetics approach to identify new factors of the TMO5/LHW pathway, we discovered a novel function of the MYB-type transcription factor, MYB12. MYB12 physically interacts with TMO5 and dampens the TMO5/LHW-mediated induction of direct target gene expression, as well as the periclinal/radial cell divisions. The expression of MYB12 is activated by the cytokinin response, downstream of TMO5/LHW, resulting in a novel MYB12-mediated negative feedback loop that restricts TMO5/LHW activity, to ensure optimal cell proliferation rates during root vascular development. [ABSTRACT FROM AUTHOR]