Maize Ethylene Response Factor ZmERF061 Is Required for Resistance to Exserohilum turcicum

Abstract

Plants have evolved a series of sophisticated defense mechanisms to help them from harm. Ethylene Response Factor (ERF) plays pivotal roles in plant immune reactions, however, its underlying mechanism in maize with a defensive function to <i>Exserohilum turcicum</i> (<i>E. turcicum</i>) remains poorly understood. Here, we isolated and characterized a novel ERF transcription factor, designated <i>ZmERF061</i>, from maize. Phylogenetic analysis revealed that ZmERF061 is a member of B3 group in the ERF family. qRT-PCR assays showed that the expression of <i>ZmERF061</i> is significantly induced by <i>E. turcicum</i> inoculation and hormone treatments with salicylic acid (SA) and methyl jasmonate (MeJA). ZmERF061 was proved to function as a nucleus-localized transcription activator and specifically bind to the GCC-box element. <i>zmerf061</i> mutant lines resulted in enhanced susceptibility to <i>E. turcicum</i> via decreasing the expression of <i>ZmPR10.1</i> and <i>ZmPR10.2</i> and the activity of antioxidant defense system. <i>zmerf061</i> mutant lines increased the expression of the SA signaling-related gene <i>ZmPR1a</i> and decreased the expression of the jasmonic acid (JA) signaling-related gene <i>ZmLox1</i> after infection with <i>E. turcicum</i>. In addition, ZmERF061 could interact with ZmMPK6-1. These results suggested that ZmERF061 plays an important role in response to <i>E. turcicum</i> and may be useful in genetic engineering breeding.