Excellence in Doctoral Education: Defining Best Practices.

Abstract

The <i>APETALA2</i>/<i>Ethylene-Responsive Transcriptional Factors</i> containing conservative <i>AP2</i>/<i>ERF</i> domains constituted a plant-specific transcription factor (TF) superfamily, called AP2/ERF. The configuration of the AP2/ERF superfamily in maize has remained unresolved. In this study, we identified the 229 <i>AP2/ERF</i> genes in the latest (B73 RefGen_v5) maize reference genome. Phylogenetic classification of the <i>ZmAP2</i>/<i>ERF</i> family members categorized it into five clades, including 27 <i>AP2</i> (<i>APETALA2</i>), 5 <i>RAV</i> (<i>Related to ABI3</i>/<i>VP</i>), 89 <i>DREB</i> (<i>dehydration responsive element binding</i>), 105 <i>ERF</i> (<i>ethylene responsive factors</i>), and a soloist. The duplication events of the paralogous genes occurred from 1.724-25.855 MYA, a key route to maize evolution. Structural analysis reveals that they have more introns and few exons. The results showed that 32 <i>ZmAP2/ERFs</i> regulate biotic stresses, and 24 <i>ZmAP2/ERFs</i> are involved in responses towards abiotic stresses. Additionally, the expression analysis showed that DREB family members are involved in plant sex determination. The real-time quantitative expression profiling of <i>ZmAP2/ERFs</i> in the leaves of the maize inbred line B73 under ABA, JA, salt, drought, heat, and wounding stress revealed their specific expression patterns. Conclusively, this study unveiled the evolutionary pathway of <i>ZmAP2/ERFs</i> and its essential role in stress and developmental processes. The generated information will be useful for stress resilience maize breeding programs.