This Article Full Text Full Text (PDF) All Versions of this Article: 141/4/1482    most recent pp.106.080697v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (19) Citing Articles via Google Scholar Google Scholar Articles by Ren, D. Articles by Zhang, S. Search for Related Content PubMed PubMed Citation Articles by Ren, D. Articles by Zhang, S. Pubmed/NCBI databases Protein UniGene Substance via MeSH Agricola Articles by Ren, D. Articles by Zhang, S.

PLANTS INTERACTING WITH OTHER ORGANISMS

Activation of Ntf4, a Tobacco Mitogen-Activated Protein Kinase, during Plant Defense Response and Its Involvement in Hypersensitive Response-Like Cell Death¹

State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China (D.R.); and Department of Biochemistry, University of Missouri, Columbia, Missouri 65211 (D.R., K.-Y.Y., G.-J.L., Y.L., S.Z.)

Mitogen-activated protein kinase (MAPK) cascades are important signaling modules in eukaryotic cells. They function downstream of sensors/receptors and regulate cellular responses to external and endogenous stimuli. Recent studies demonstrated that SIPK and WIPK, two tobacco (Nicotiana spp.) MAPKs, are involved in signaling plant defense responses to various pathogens. Ntf4, another tobacco MAPK that shares 93.6% and 72.3% identity with SIPK and WIPK, respectively, was reported to be developmentally regulated and function in pollen germination. We found that Ntf4 is also expressed in leaves and suspension-cultured cells. Genomic analysis excluded the possibility that Ntf4 and SIPK are orthologs from the two parental lines of the amphidiploid common tobacco. In vitro and in vivo phosphorylation and activation assays revealed that Ntf4 shares the same upstream MAPK kinase, NtMEK2, with SIPK and WIPK. Similar to SIPK and WIPK, Ntf4 is also stress responsive and can be activated by cryptogein, a proteinaceous elicitin from oomycetic pathogen Phytophthora cryptogea. Tobacco recognition of cryptogein induces rapid hypersensitive response (HR) cell death in tobacco. Transgenic Ntf4 plants with elevated levels of Ntf4 protein showed accelerated HR cell death when treated with cryptogein. In addition, conditional overexpression of Ntf4, which results in high cellular Ntf4 activity, is sufficient to induce HR-like cell death. Based on these results, we concluded that Ntf4 is multifunctional. In addition to its role in pollen germination, Ntf4 is also a component downstream of NtMEK2 in the MAPK cascade that regulates pathogen-induced HR cell death in tobacco.

² These authors contributed equally to the paper.

³ Present address: Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500–757, Republic of Korea.

⁴ Present address: College of Bioengineering, Inner Mongolia Agricultural University, Huhhot 010018, China.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Shuqun Zhang (zhangsh{at}missouri.edu).

Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.106.080697.

^* Corresponding author; e-mail zhangsh{at}missouri.edu; fax 573–884–9676.

Received March 21, 2006; returned for revision June 14, 2006; accepted June 16, 2006.

This article has been cited by other articles:

				S. C. Popescu, G. V. Popescu, S. Bachan, Z. Zhang, M. Gerstein, M. Snyder, and S. P. Dinesh-Kumar MAPK target networks in Arabidopsis thaliana revealed using functional protein microarrays Genes & Dev., January 1, 2009; 23(1): 80 - 92. [Abstract] [Full Text] [PDF]

				J. J. Rudd, J. Keon, and K. E. Hammond-Kosack The Wheat Mitogen-Activated Protein Kinases TaMPK3 and TaMPK6 Are Differentially Regulated at Multiple Levels during Compatible Disease Interactions with Mycosphaerella graminicola Plant Physiology, June 1, 2008; 147(2): 802 - 815. [Abstract] [Full Text] [PDF]

				S. Asai, K. Ohta, and H. Yoshioka MAPK Signaling Regulates Nitric Oxide and NADPH Oxidase-Dependent Oxidative Bursts in Nicotiana benthamiana PLANT CELL, May 1, 2008; 20(5): 1390 - 1406. [Abstract] [Full Text] [PDF]

				J. Wu, C. Hettenhausen, M. C. Schuman, and I. T. Baldwin A Comparison of Two Nicotiana attenuata Accessions Reveals Large Differences in Signaling Induced by Oral Secretions of the Specialist Herbivore Manduca sexta Plant Physiology, March 1, 2008; 146(3): 927 - 939. [Abstract] [Full Text] [PDF]

				P. K. Kandoth, S. Ranf, S. S. Pancholi, S. Jayanty, M. D. Walla, W. Miller, G. A. Howe, D. E. Lincoln, and J. W. Stratmann Tomato MAPKs LeMPK1, LeMPK2, and LeMPK3 function in the systemin-mediated defense response against herbivorous insects PNAS, July 17, 2007; 104(29): 12205 - 12210. [Abstract] [Full Text] [PDF]

				J. Wu, C. Hettenhausen, S. Meldau, and I. T. Baldwin Herbivory Rapidly Activates MAPK Signaling in Attacked and Unattacked Leaf Regions but Not between Leaves of Nicotiana attenuata PLANT CELL, March 1, 2007; 19(3): 1096 - 1122. [Abstract] [Full Text] [PDF]