Many plants have only one layer of water-impermeable epidermis on the surface of their bodies to protect themselves from desiccation.
Since only the outermost cells differentiate into epidermal cells during the "embryo" period, which is a baby plant, it is thought that plant cells recognize the "outer" position and determine their own fate. ing.However, the mechanism by which plant cells recognize the outermost position and differentiate into the epidermis remains a mystery.

　In the model plant Arabidopsis thaliana, the ATML1 gene is known as a gene that makes the epidermis.In this study, we visualized and observed the localization (location) of the ATML1 protein in order to investigate the regulation of the activity of the ATML1 protein, which promotes the transcription of multiple genes required for epidermis formation in the cell nucleus.

　As a result, it was found that the ATML1 protein was accumulated only in the outermost cells and hardly detected in the inner cells.Furthermore, it was found that even if the ATML1 protein is produced in the inner cells, the accumulation of the ATML1 protein in the cell nucleus is suppressed to a low level in the inner cells.This clarified the mechanism by which the activity of ATML1 protein is limited to the outermost cells by suppressing the amount of ATML1 protein and its accumulation in the cell nucleus, and the plant forms a further epidermis.

　The characteristic of plant cells that the cell fate can be flexibly changed according to the position placed in the individual body has been known for a long time.However, how plant cells recognize their position has not been well understood.This result is the discovery of a new mechanism in which cells change the activity of genes according to their position, and it can be said that a part of the mechanism by which plant cells recognize their position and differentiate is elucidated.

Paper information:[Development] ATML 1 activity is restricted to the outermost cells of the embryo through post-transcriptional suppressions