The maturation of organs implies, in both animals and plants, changes in their shape and anatomy. These changes occur over time, which is why there are real molecular clocks that mediate and mark the interaction of specific genes, at certain times, so that the correct morphology is assumed.

A new study by the Department of Biology and Biotechnology "Charles Darwin" of Sapienza, identified the Arabidopsis thaliana model plant as the molecular clock involved in the regulation of root formation. Specifically, the team of researchers coordinated by Raffaele Dello Ioio investigated in the plant the functioning of one of the mechanisms that regulate the asymmetric division of the tissue, resulting in an increase in the number of layers from one to two.

"This work, just published on the magazine Current Biology, has made it possible to identify one of these clocks, which enables plants to adapt to the outside environment and its variations," says Raffaele Dello Ioio. "Eight days after germination, the moment when the embryo in the seed begins to leave the quiescent phase, there is a reduction in the expression of some small RNA molecules, the microRNA 165 and 166. The asymmetric division of the cortex, a component of the root structure, results from the lower expression of the microRNAs, which exert a positive control on the levels of the phytohormone gibberellin and a negative control on the PHABULOSA transcription factor."

Raffaele dello Ioio, in 2019 awarded the "Antonio Feltrinelli giovani" prize by the Accademia dei Lincei for his studies on the genetic-molecular circuits regulating the correct development of plant organs, concluded: "identifying these mechanisms not only allows us to understand how organs ripen, but can also help scientists to understand how to manipulate these mechanisms to improve plants adaptation to environmental variations."

References:

A PHABULOSA-Controlled Genetic Pathway Regulates Ground Tissue Patterning in the Arabidopsis Root – Gaia Bertolotti, Simon Josef Unterholzner, Daria Scintu, Elena Salvi, Noemi Svolacchia, Riccardo Di Mambro, Veronica Ruta, Francisco Linhares Scaglia, Paola Vittorioso, Sabrina Sabatini, Paolo Costantino, Raffaele Dello Ioio – Current Biology, 2020. DOI https://doi.org/10.1016/j.cub.2020.10.038

Further Information

Raffaele Dello Ioio
Department of Biology and Biotechnology "Charles Darwin"
raffaele.delloioio@uniroma1.it