期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1998
卷号:95
期号:12
页码:7225-7230
DOI:10.1073/pnas.95.12.7225
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:It has been demonstrated that both salicylic acid and fungal elicitors activate a 48-kDa mitogen-activated protein kinase termed salicylic acid-induced protein kinase (SIPK) in tobacco suspension cells. Here, we show that infiltration of these agents into tobacco leaves also activates SIPK. Of particular interest, infiltration of water alone activated a kinase of the same size, possibly because of wounding and/or osmotic stresses. The kinetics of kinase activation, however, differ for these different treatments. Various mechanical stresses, including cutting and wounding by abrasion, also activated a 48-kDa kinase. By using an immune-complex kinase assay with antibodies specific for SIPK or wounding-induced protein kinase, we demonstrate that this wounding-activated 48-kDa kinase is SIPK, rather than wounding-induced protein kinase, as reported [Seo, S., Okamoto, M., Seto, H., Ishizuka, K., Sano, H. & Ohashi, Y. (1995) Science 270, 1988-1992]. Activation of SIPK after wounding was associated with tyrosine phosphorylation but not with increases in SIPK mRNA or protein levels. Thus, the same mitogen-activated protein kinase, SIPK, appears to facilitate signaling for two distinct pathways that lead to disease resistance responses and wounding responses.