The group led by Dr. Juan Carlos del Pozo has found that the transcription factor OBP4 activates cell proliferation in differentiated pericycle cells. This activation promotes the formation of callus, a mass of proliferative cells in an undifferentiated state. This callus mass has the potential to regenerate functional organs or entire plant under determinate conditions.
Plant growth and development requires a continuous balance between cell division and differentiation. In root meristems, meristematic cells divide continuously to sustain root growth. Later, these cells differentiate, acquiring specialized functions, but losing their mitotic potential. Some plant cells types, such as pericycle cells, have a remarkable plasticity to be reprogrammed and to regenerate new organs and functional plants. However, the molecular mechanisms underlying cell reprogramming are not completely known.
In this work, a functional screening of transcription factors, using the Spanish collection TRANSPLANTA, identifies Arabidopsis
Figure: A) Phenotype of control (Ei-GFP) and OBP4-overexpressing lines after inducing the expression of GFP or OBP4 during 24, 48 or 72 hours by addition of estradiol in the medium. B) Induction of OBP4::GUS during callus formation in a CIM (Callu-inducing-medium). C) Overexpression of OBP4 promotes callus formation in CIM medium. D) Overexpression of OBP4 increases J0121 pericycle marker expression.