Discovery of a mechanism that represses plant totipotency

RIKEN CSRS researchers have discovered that PRC2 (Polycomb Repressive Complex 2) loss-of-function mutants complete cell differentiation but later develop somatic embryos and callus (unorganized cell mass). Researchers also determined that the mutant forms this aggregate after undergoing initial normal differentiation accompanied by endoreduplication.

PRC2 suppresses gene expression in specific domains through histone methylation. CSRS researchers analyzed the Arabidopsis root genome to find out which genes PRC2 was suppressing. They found that the genes for the dedifferentiation promoting factor WIND3 (also discovered by the team) and the embryogenesis regulating factor LEC2 were among the suppressed genes. Accordingly, forced expression of the WIND3 and LEC2 genes in plants with properly functioning PRC2 resulted in root-cell-derived callus formation.

These findings are expected to contribute to efficient tissue culturing for plant production and other applications.

 

Original article
Nature Plants doi: 10.1038/NPLANTS.2015.89
M. Ikeuchi, A. Iwase, B. Rymen, H. Harashima, M. Shibata, M. Ohnuma, C. Breuer, A. K. Morao, M. d. Lucas, L. D. V. J. Goodrich, S. M. Brady, F. Roudier, K. Sugimoto,
"PRC2 represses dedifferentiation of mature somatic cells in Arabidopsis".

Contact
Keiko Sugimoto; Team Leader
Momoko Ikeuchi; Special Postdoctoral Researcher
Akira Iwase; Research Scientist
Cell Function Research Team