The extensin multigene family responds differentially to superoxide or hydrogen peroxide in tomato cell cultures

FEBS Letters

Wisniewski, Jean-Pierre¹  Agnel, Jean-Pierre¹  Cornille, Patrick¹  Montillet, Jean-Luc¹ 

[1] CEA, CE de Cadarache, Département de Physiologie Végétale and de Microbiologie Végétale, 13108 St Paul-lez-Durance, France

关键词: Active oxygen species;    Extensin;    Hydrogen peroxide;    Lipid peroxidation;    Superoxide anion;    Tomato cell;    AOS;    active oxygen species;    CytC;    cytochrome c;    GO;    glucose oxidase;    PGA;    polygalacturonic acid;    PR protein;    pathogenesis-related protein;    XO;    xanthine oxidase;   

DOI  :  10.1016/S0014-5793(99)00315-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Changes in extensin gene expression were examined in cultured tomato cells following treatments leading to the production of activated oxygen species. Digitonin, a steroid glycoalkaloid compound, has been shown to trigger a rapid and transient production of superoxide anion, O^−⋅ ₂. 6 h after application of 50 or 100 μM of digitonin, the accumulation of four extensin transcripts (1.5, 2.6, 4.0 and 6.1 kb) was observed. Superoxide dismutase strongly inhibited the digitonin-mediated response, suggesting a key role of O^−⋅ ₂ in the signalling cascade. Furthermore, cells treated with enzymatically produced O^−⋅ ₂ generated by xanthine oxidase (0.015 U/ml) gave a similar extensin response and again, SOD exerted a strong inhibitory effect on the response. On the other hand, H₂O₂ (2 mM) or the enzymatic H₂O₂ generator, glucose oxidase (0.34 U/ml), elicited the accumulation of only three of the four transcripts (1.5, 2.6 and 4.0 kb), indicating that the corresponding genes could be regulated either by H₂O₂ or O^−⋅ ₂ but that the gene encoding the 6.1 kb transcript was exclusively expressed in response to O^−⋅ ₂. Finally, it was shown that lipid peroxidation, which was only induced when cells were exposed to H₂O₂, did not participate in the AOS-mediated gene expression for extensin. It can be concluded from these results that tomato cells are able to discriminate H₂O₂ from O^−⋅ ₂ and they probably sense the latter by the specific oxidation of an extracellular component.

【 授权许可】

Unknown