preprint
Transcription factor TGA2 is essential for UV-B stress tolerance controlling oxidative stress in Arabidopsis
Fecha
2020Registro en:
10.1101/2020.05.24.113589
Autor
Herrera Vásquez, Ariel Esteban
Fonseca Cárdenas, Alejandro Alfredo
Ugalde Valdivia, José Manuel
Lamig Giannini, Liliana Andrea
Seguel Avello, Aldo Luis
Moyano Yugovic, Tomás Custodio
Gutiérrez Ilabaca, Rodrigo Antonio
Salinas, Paula
Vidal, Elena A.
Holuigue Barros, Loreto
Institución
Resumen
Plants possess a diversity of Reactive Oxygen Species (ROS)-processing enzymes involved in sensing and controlling ROS levels under basal and stressful conditions. There is little information on the transcriptional regulators that control the expression of these ROS-processing enzymes, particularly at the onset of the defense response to abiotic stress. Filling this gap, this paper reports a critical role for Arabidopsis TGA class II factors (TGA2, TGA5, and TGA6) in the tolerance response to UV-B light and photooxidative stress, by activating the expression of genes with antioxidative roles. We identified two clusters of genes responsive to UV-B and activated by TGA2/5/6 were identified using RNAseq and clustering analysis. The GSTU gene family, which encodes glutathione transferase enzymes from the Tau subclass, was overrepresented in these clusters. We corroborated the TGA2-mediated activation in response to UV-B for three model genes (GSTU7, GSTU8, and GSTU25) using RT-qPCR and ChIP analyses. Interestingly, using tga256 mutant and TGA2- and GSTU7-complemented mutant plants, we demonstrated that TGA2-mediated induction of GSTU genes is essential to control ROS levels and oxidative damage after UV-B and MeV treatments. This evidence positions TGA class II factors, particularly TGA2, as a key players in the redox signaling network of Arabidopsis plants.