G-quadruplex: Potential epigenetic memory involved in priming induced by Trichoderma in maize plants

PIGA ERNESTO; VARGAS, WALTER A.; ARMAS PABLO; CAMPOS-BERMUDEZ VALERIA; AGOSTINI ROMINA; RIUS SEBASTIÁN P.

Congreso; The Annual Plant Biology Meeting, ASPB.; 2020

Trichoderma spp. is considered as promising biological control agents. They can trigger Induced Systemic Resistance (ISR) to prevent future pathogenic attacks. Priming of plant defenses is marked by changes in transcriptional, metabolic, and epigenetic levels after stimulus perception. The primed plants have an epigenetic environmental memory that upon pathogenic attack, they are able to mount a quicker and/or robust immune response to effectively ward off pathogenic infections and/or develop stress tolerance. Epigenetic regulation involves the restructuring of chromatin through covalent modifications of DNA and histones and the accessibility of chromatin. The G-quadruplex (G4) elements comprise a class of nucleic acid structures formed by stacking of guanine base quartets in a quadruple helix. G4 motifs have been shown to affect a vast array of genetic functions, including transcription, translation, replication, recombination, and DNA repair. Interestingly, more recent work suggests roles for G4, in association with quadruplex-interacting proteins, in epigenetics through both DNA and histone modifications.In this work we sought to further investigate the G-quadruplex epigenetic reprogramming in leaves from maize plants inoculated with T. atrovidire. The main goal of our research was to determine the presence of the G4 structures at the genomic DNA level using Dot-Blot and to evaluate the enrichment of putative Quadruplex forming G-Rich Sequences (QGRS) in previously selected priming gene promoters. The results obtained reveal that at 6 days post-inoculation with Trichoderma, there is an increase in the concentration of G4 with respect to the control condition. In addition, the in silico analysis of the promoters revealed a significant enrichment of QGRS mainly in the promoters of the JAZ 8, Probable WRKY transcription factor 69, MAP kinase1, 1-aminocyclopropane-1-carboxylate oxidase and ethylene-responding AP2-EREBP-transcription factor.