SHR (green) starts leaking past its usual endodermal endpoint when SCR isn't there to catch it.

BENFEY/AAAS

Adiffusible plant transcription factor is kept from wandering too far by hitching to a nuclear partner, report Hongchang Cui, Philip Benfey (Duke University, Durham, NC), and colleagues.

The wanderer is SHORTROOT (SHR), which is made in the root vascular tissue and then diffuses outward. In the neighboring cell layer, it partners with another transcription factor, called SCARECROW (SCR), to help create the plant endodermal layer. The Arabidopsis endodermis is a single layer surrounding the root vasculature. Benfey and colleagues wondered why SHR's diffusion stops here.

Two cell lines with reduced SCR activity provided the answer. The lower the SCR activity, the more SHR leaked past the first cell layer and began to specify extra endodermis. The effects suggest that SCR physically tethers its partner in the nucleus of...

The Rockefeller University Press
2007
The Rockefeller University Press
2007
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