Involvement of Nt ERF 3 in the cell death signalling pathway mediated by SIPK / WIPK and WRKY 1 in tobacco plants

• Published in: Plant biology (Stuttgart, Germany) Vol. 17; no. 5; pp. 962 - 972
• Main Authors: Ogata, T., Okada, H., Kawaide, H., Takahashi, H., Seo, S., Mitsuhara, I., Matsushita, Y.
• Format: Journal Article
• Language: English
• Published: 01.09.2015
• ISSN: 1435-8603; 1438-8677
• DOI: 10.1111/plb.12349

Abstract We previously reported that one of the ethylene response factors ( ERF s), Nt ERF 3, and other members of the subgroup VIII ‐a ERF s of the AP 2/ ERF family exhibit cell death‐inducing ability in tobacco leaves. In this study, we focused on the involvement of Nt ERF 3 in a cell death signalling pathway in tobacco plants, particularly downstream of Nt SIPK /Nt WIPK and Nt WRKY 1, which are mitogen‐activated protein kinases and a phosphorylation substrate of Nt SIPK , respectively. An ERF ‐associated amphiphilic repression ( EAR ) motif‐deficient Nt ERF 3b mutant ( Nt ERF 3bΔ EAR ) that lacked cell death‐inducing ability suppressed the induction of cell death caused by Nt ERF 3a . The transient co‐expression of Nt ERF 3bΔ EAR suppressed the hypersensitive reaction ( HR )‐like cell death induced by Nt SIPK and Nt WRKY 1 . The induction of cell death by Nt SIPK and Nt WRKY 1 was also inhibited in transgenic plants expressing Nt ERF 3bΔ EAR . Analysis of gene expression, ethylene production and cell death symptoms in salicylic acid‐deficient tobacco plants suggested the existence of some feedback regulation in the HR cell death signalling pathway mediated by SIPK / WIPK and WRKY 1. Overall, these results suggest that Nt ERF 3 functions downstream of Nt SIPK / Nt WIPK and Nt WRKY 1 in a cell death signalling pathway, with some feedback regulation.