ANAC055 and ANAC092 contribute non-redundantly in an EIN2-dependent manner to Age-Related Resistance in Arabidopsis

As Arabidopsis matures it becomes resistant to virulent Pseudomonas syringae pv. tomato (Pst), a defense response known as Age-Related Resistance (ARR). The contribution of two NAC transcription factors (ANAC055 and ANAC092) and jasmonic acid/ethylene (JA/ET) signaling to ARR was examined by comparing Pst growth in wild-type plants, nac mutants, an ANAC092-overexpressing line, lox2, and ein2-1. PDF1.2 expression and anac055anac092 double mutant analysis suggests that ANAC055 and ANAC092 play non-redundant roles in ARR. Additionally, ANAC092 contributes to the initiation of flowering in short day-grown plants. ANAC055 and ANAC092 expression was reduced in partially ARR-defective ein2-1 suggesting that regulation of ANAC055 and ANAC092 by EIN2 contributes to ARR.

► ANAC092 contributes to the promotion of flowering in short day-grown Arabidopsis.
► ANAC055 contributes positively, while ANAC092 contributes negatively to ARR.
► ANAC055 and ANAC092 contribute to controlling PDF1.2 and LOX2 expression during ARR.
► PDF1.2a expression is enhanced in ARR-competent compared to ARR-incompetent plants.
► EIN2 regulates expression of ANAC055 and ANAC092 during ARR.