It is rather intuitive that cellular activity must be somehow coordinate during organ growth. For plants, development is based on the activity of meristems, which is how the tissues of undifferentiated cells that divide giving rise to new cells are called in botany.

A new study coordinated by Sabrina Sabatini of the Department of Biology and Biotechnology Charles Darwin, in collaboration with the University of Pisa, demonstrated how the mechanism of development and differentiation of cells in plants is regulated.

The results, published in Current Biology, revealed the existence of a single mechanism that affects the entire activity: it is sufficient to regulate the levels of the auxin hormone to coordinate the division and differentiation of all tissues and thus have a growth harmonic and coordinate of the organ.It was already known that destroying specific cells or silencing a gene of the LRC tissue (Lateral Root Cap) affects the size of the meristem.

However, the molecular mechanism involved in the process was unknown until recently.

"By observing the growth of a root," Sabrina Sabatini explains, "we have discovered how it depends on the position of the transition zone, which is the boundary that separates the differentiating cells. This position can be regulated by manipulating only the LRC tissue and is controlled by the interaction of two plant hormones, cytokinins and auxin."

"It is therefore a decisive discovery,"  concludes Sabatini, "that opens up new potentially revolutionary scenarios in the research on the mechanisms that give origin to many genetic diseases or tumors."

References:

The Lateral Root Cap Acts as an Auxin Sink that Controls Meristem Size - Di Mambro, R., Svolacchia, N., Ioio, R. D., Pierdonati, E., Salvi, E., Pedrazzini, E., Vitale, A., Perilli, S., Sozzani, R., Benfey P. N., Busch, W., Costantino, P., & Sabatini, S. - Current Biology 2019 
DOI: https://doi.org/10.1016/j.cub.2019.02.022

Further Information

Sabrina Sabatini
Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome 
sabrina.sabatini@uniroma1.it