SALICYLIC ACID SIGNALING PATHWAY AS KEY PLAYER IN THE EARLY ACTIVATION OF IMMUNE RESPONSES IN MAIZE

AGOSTINI RB; POSTIGO, A; RIUS, SP.; CAMPOS BERMUDEZ VA; VARGAS, WA.

Congreso; LIV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2018

In the present study, we investigated the induced systemic resistance (ISR) activated by the beneficial fungus Trichoderma atroviride in maize plants, and the early immunological responses triggered after challenge with the ear rot pathogen Fusarium verticillioides. By transcriptional analysis, we were able to identify the gene core set specifically modulated in silks of maize plants expressing ISR. Our results showed that the main transcriptional reprogramming falls into genes involved in five main functional categories: cell structure/cell wall, amino acid and protein metabolism, stress responses,signaling, and transport. Among these ISR-related genes, it is important to highlight novel findings regarding hormone metabolism and signaling. The expression of hormone-dependent genes was in good agreement with the ABA, JA and SA levels detected in the plants under study. The experimental design allowed the identification of novel regulatory elements related to a heightened state of defense in silks and suggests that steroids and SA are central components of a master regulatory network controlling the immunity of silks during ISR. The results presented also provide evidence about the molecular mechanisms used by maize silks against F. verticilliodes to counteract pathogenic development and host invasion.