Identification of novel ERF transcription factor genes in papaya and analysis of their expression in different tissues and in response to the plant defense inducer benzothiadiazole (BTH)

• Four novel ERF transcription factor cDNAs (CpERF5–CpERF8) were characterized in papaya.
• CpERF5, CpERF6 and CpERF8 were expressed in vegetative and reproductive tissues.
• CpERF7 was the gene most up-regulated by the plant defense inducer benzothiadiazole.
• CpERF7 was up-regulated by the bacterial pathogen Pseudomonas syringae.
• CpERF7 encodes a nuclear protein with transcription factor activity.

In the present study, we isolated and characterized four novel papaya ERF transcription factor cDNAs (CpERF5–CpERF8) with homology to ERF genes involved in disease resistance, and analyzed their expression in different tissues and in response to the plant defense inducer benzothiadiazole (BTH). Interestingly, CpERF7 was the most responsive to BTH. Further examination revealed that it was also up-regulated by the bacterial pathogen Pseudomonas syringae and encoded a nuclear protein with transcription factor activity. These novel insights on CpERF7 have provided a valuable platform to continue dissecting the BTH signal transduction pathway that may lead to engineering disease resistance in papaya.