BnERF114.A1, a Gene Encoding an APETALA2/ETHYLENE RESPONSE FACTOR, Regulates Plant Architecture Through Blocking Auxin Efflux in Apex of Rapeseed Plant

Abstract Plant architecture is very important for rapeseed breeding. Here, we reported an ETHYLENE RESPONSE FACTOR (ERF) transcription factor BnERF114.A1 of Brassica napus participating in plant architecture regulation. BnERF114.A1 is a member of ERF family group x-a, encoding a putative protein of 252 aa which consisting of an AP2/ERF domain and a conserved CMX-1 motif. BnERF114.A1 located in nucleus and had transcriptional activity with its functional region located in 142 aa ~ 252 aa of its C-terminus. The GUS staining analysis revealed that BnERF114.A1 highly expressed in leaf primordia, shoot apical meristem, leaf marginal meristem, and reproductive organs. Ectopic expression of BnERF114.A1 in Arabidopsis reduced plant height, increased branch numbers and silique numbers per plants, and finally increased seed yield per plant. Further investigation demonstrated that overexpression of BnERF114.A1 can inhibit IAA efflux and cause accumulation of auxin in apex, and arrest apical dominance in Arabidopsis. The findings suggested BnERF114.A1 could provide a candidate gene for rapeseed plant architecture molecular breeding.