Spermine signalling in tobacco: activation of mitogen‐activated protein kinases by spermine is mediated through mitochondrial dysfunction
Year: 2003
Type: article
Abstract: Polyamines (PAs) play important roles in cell proliferation, growth and environmental stress responses of all living organisms. In this study, we examine whether these compounds act as signal mediators. Spermine (Spm) specifically activated protein kinases of tobacco leaves, which were identified as salicylic acid (SA)-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK), using specific antibodies. Upon Spm treatment, upregulation of WIPK, but not SIPK, was observed. Spm-induced mitogen-activated protein kinases (MAPKs) activation and WIPK upregulation were prevented upon pre-treatment with antioxidants and Ca2+ channel blockers. Additionally, Spm specifically stimulated expression of the alternative oxidase (AOX) gene, which was disrupted by these antioxidants and Ca2+ channel blockers. Bongkrekic acid (BK), an inhibitor of the opening of mitochondrial permeability transition (PT) pores, suppressed MAPKs activation and accumulation of WIPK and AOX mRNA. Our data collectively suggest that Spm causes mitochondrial dysfunction via a signalling pathway in which reactive oxygen species and Ca2+ influx are involved. As a result, the phosphorylation activities of the two MAPK enzymes SIPK and WIPK are stimulated.
Source: The Plant Journal
Authors: Yoshihiro Takahashi, Thomas Berberich, Atsushi Miyazaki, Shigemi Seo, Yuko Ohashi, Tomonobu Kusano
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2103764596