A mitogen-activated protein kinase NtMPK4 activated by SIPKK is required for jasmonic acid signaling and involved in ozone tolerance via stomatal movement in tobacco [Nicotiana]

• Published in: Plant and cell physiology Vol. 46; no. 12; pp. 1902 - 1914
• Main Authors: Gomi, K.(National Inst. of Agrobiological Sciences, Tsukuba, Ibaraki (Japan)), Ogawa, D, Katou, S, Kamada, H, Nakajima, N, Saji, H, Soyano, T, Sasabe, M, Machida, Y, Mitsuhara, I, Ohashi, Y, Seo, S
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.12.2005; Oxford Publishing Limited (England)
• Subjects: 1-aminocyclopropane-1-carboxylate synthase; ACIDE JASMONIQUE; ACIDO JASMONICO; ACS; air pollution; allene oxide synthase; analysis; AOS; complementary DNA; Cyclopentanes; Cyclopentanes - pharmacology; DNA, Plant; DNA, Plant - analysis; drug effects; Enzyme Activation; enzymology; Epidermis; Gene Expression Regulation, Plant; gene overexpression; Gene Silencing; Genes, Plant; genetics; glutathione S-transferase; GST; JASMONIC ACID; MAP kinase; MAPK kinase; MAPK/MPK; MAPKK/MEK/MKK; MBP; metabolism; mitogen-activated protein kinase; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinase Kinases - genetics; Mitogen-Activated Protein Kinase Kinases - metabolism; Mitogen-Activated Protein Kinases; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - metabolism; Molecular Sequence Data; myelin basic protein; NICOTIANA; Nicotiana - drug effects; Nicotiana - enzymology; Nicotiana - genetics; Nicotiana - physiology; Nicotiana tabacum; nucleotide sequences; open reading frame; ORF; Oxylipins; OZONE; Ozone - pharmacology; OZONO; pathogenesis-related; pharmacology; photosynthetic photon flux density; physiology; PI-II; plant biochemistry; plant ecology; plant genetics; Plant Leaves; Plant Leaves - physiology; Plant Proteins; Plant Proteins - genetics; Plant Proteins - physiology; pollutants; PPFD; protein kinases; proteinase inhibitor-II; RACE; rapid amplification of cDNA ends; Reverse Transcriptase Polymerase Chain Reaction; reverse transcription–PCR; RT–PCR; salicylic acid; salicylic acid-induced protein kinase; salicylic acid-induced protein kinase kinase; signal transduction; Signal Transduction - drug effects; Signal Transduction - physiology; SIPK; SIPKK; Stomata; stomatal movement; stress tolerance; Tobacco; TOLERANCE; TOLERANCIA; WIPK; Wound response; wound-induced protein kinase
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pci211

The mitogen-activated protein kinase (MAPK) cascade is involved in responses to biotic and abiotic stress in plants. In this study, we isolated a new MAPK, NtMPK4, which is a tobacco homolog of Arabidopsis MPK4 (AtMPK4). NtMPK4 was activated by wounding along with two other wound-responsive tobacco MAPKs, WIPK and SIPK. We found that NtMPK4 was activated by salicylic acid-induced protein kinase kinase (SIPKK), which has been isolated as an SIPK-interacting MAPK kinase. In NtMPK4 activity-suppressed tobacco, wound-induced expression of jasmonic acid (JA)-responsive genes was inhibited. NtMPK4-silenced plants showed enhanced sensitivity to ozone. Inversely, transgenic tobacco plants, in which SIPKK or the constitutively active type SIPKKEE was overexpressed, exhibited greater responsiveness to wounding with enhanced resistance to ozone. We further found that NtMPK4 was expressed preferentially in epidermis, and the enhanced sensitivity to ozone in NtMPK4-silenced plants was caused by an abnormal regulation of stomatal closure in an ABA-independent manner. These results suggest that NtMPK4 is involved in JA signaling and in stomatal movement.