2026-06-01T12:30:40Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/379262026-02-03T11:33:38Zcom_10630_2254col_10630_37953

Deregulation of phenylalnine biosynthesis evolved with the emergence of vascular plants. El-Azaz-Ciudad, Jorge Cánovas-Ramos, Francisco Miguel Barcelona, Belén Ávila-Sáez, Concepción De-la-Torre-Fazio, Fernando Nicolás Fenilalanina Plantas - Sistema vascular Phenylalanine (Phe) is the precursor of essential secondary products in plants. Here we show that a key, rate-limiting step in Phe biosynthesis, which is catalyzed by arogenate dehydratase, experienced feedback de-regulation during evolution. Enzymes from microorganisms and type-I ADTs from plants are strongly feedback-inhibited by Phe, while type-II isoforms remain active at high levels of Phe. We have found that type-II ADTs are widespread across seed plants and their overproduction resulted in a dramatic accumulation of Phe in planta, reaching levels up to 40 times higher than those observed following the expression of type-I enzymes. Punctual changes in the allosteric binding site of Phe and adjacent region are responsible for the observed relaxed regulation. The phylogeny of plant ADTs evidences that the emergence of type-II isoforms with relaxed regulation occurred at some point in the transition between nonvascular plants and tracheophytes, enabling the massive production of Phe-derived compounds, primarily lignin, a hallmark of vascular plants. 2025-02-19T09:40:18Z 2025-02-19T09:40:18Z 2025-02-19T09:40:18Z 2022 journal article Jorge El-Azaz, Francisco M Cánovas, Belén Barcelona, Concepción Ávila, Fernando de la Torre, Deregulation of phenylalanine biosynthesis evolved with the emergence of vascular plants, Plant Physiology, Volume 188, Issue 1, January 2022, Pages 134–150, https://doi.org/10.1093/plphys/kiab454 0140-7791 https://hdl.handle.net/10630/37926 10.1093/plphys/kiab454 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Oxford University Press