Objective Bioinformatics of BoiERF5 was studied to understand the functions of ethylene response factors (ERFs) gene in response to gray mold and sclerotinia rot of a plant.

Method The gene of ERFs in Brassica oleracea var. italica (BoiERF5) was cloned using PCR method, followed by sequence analysis and phylogenetic analysis using ProtParam, SMART, Clustal X and Mega 3.1. Expressions of the gene under Botrytis cinerea and Sclerotinia sclerotiorum infections were determined by qRT-PCR, and vectors constructed for the determinations of subcellular localization and disease resistance.

Result The full-length of BoiERF5 was 891 bp without introns. It encoded 286 amino acids, contained one AP2/ERF domain, and was most homologous in the same phylogenetic tree with the proteins in B. cretica and B. rapa. After inoculating B. cinerea on broccoli leaves, the expression of BoiERF5 initially increased to peak in 36 h then decreased; while the S. sclerotiorum infection caused the gene to peak in 36 h/48 h. BoiERF5 located in nucleus, same as the predictions shown by online source. Overexpressed BoiERF5 significantly enhanced the resistance of Nicotiana benthamiana leaves to S. sclerotiorum and B. cinerea, which was accompanied by a significant increase in the expression of the pathogenesis-related NbPDF1.2 but not in that of NbPR1.

Conclusion Expression of BoiERF5 could be induced by either B. cinerea or S. sclerotiorum. The overexpression significantly raised the resistance of N. benthamiana leaves to both pathogens.