Constitutive expression of mammalian nitric oxide synthase in tobacco plants triggers disease resistance to pathogens

• Published in: Molecules and cells Vol. 34; no. 5; pp. 463 - 471
• Main Authors: Chun, H.J., Gyeongsang National University, Jinju, Republic of Korea, Park, H.C., Gyeongsang National University, Jinju, Republic of Korea, Koo, S.C., National Institute of Crop Science, RDA, Suwon, Republic of Korea, Lee, J.H., Gyeongsang National University, Jinju, Republic of Korea, Park, C.Y., Gyeongsang National University, Jinju, Republic of Korea, Choi, M.S., National Institute of Crop Science, RDA, Suwon, Republic of Korea, Kang, C.H., Gyeongsang National University, Jinju, Republic of Korea, Baek, D.W., Gyeongsang National University, Jinju, Republic of Korea, Cheong, Y.H., Sunchon National University, Sunchon, Republic of Korea, Yun, D.J., Gyeongsang National University, Jinju, Republic of Korea, Chung, W.S., Gyeongsang National University, Jinju, Republic of Korea, Cho, M.J., Gyeongsang National University, Jinju, Republic of Korea, Kim, M.C., Gyeongsang National University, Jinju, Republic of Korea
• Format: Journal Article
• Language: English
• Published: Springer Korean Society for Molecular and Cellular Biology 01.11.2012; Korea Society for Molecular and Cellular Biology; 한국분자세포생물학회
• Subjects: ACIDE SALICYLIQUE; ACIDO SALICILICO; Animals; Biochemistry; Biomedical and Life Sciences; Biomedicine; Biotechnology; Cell Biology; Cyclopentanes - metabolism; Disease Resistance - genetics; ESPECIES DE OXIGENO REACTIVO; Gene Expression Regulation, Plant; Hydrogen Peroxide - metabolism; Life Sciences; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana - microbiology; NITRIC OXIDE; nitric oxide synthase; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase - metabolism; OXIDO NITRICO; OXYDE NITRIQUE; Oxylipins - metabolism; plant defense signaling; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - microbiology; Pseudomonas - genetics; Pseudomonas - physiology; Rats; REACTIVE OXYGEN SPECIES; Salicylic Acid - metabolism; SALICYLIC ACIDS; 생물학; nitric oxide (NO); nitric oxide synthase (NOS); salicylic acid; plant defense signaling; reactive oxygen species
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-012-0213-0

Nitric oxide (NO) is known for its role in the activation of plant defense responses. To examine the involvement and mode of action of NO in plant defense responses, we introduced calmodulin-dependent mammalian neuronal nitric oxide synthase (nNOS), which controls the CaMV35S promoter, into wild-type and NahG tobacco plants. Constitutive expression of nNOS led to NO production and triggered spontaneous induction of leaf lesions. Transgenic plants accumulated high amounts of H₂O₂, with catalase activity lower than that in the wild type. nNOS transgenic plants contained high levels of salicylic acid (SA), and they induced an array of SA-, jasmonic acid (JA)-, and/or ethylene (ET)-related genes. Consequently, NahG co-expression blocked the induction of systemic acquired resistance (SAR)-associated genes in transgenic plants, implying SA is involved in NO-mediated induction of SAR genes. The transgenic plants exhibited enhanced resistance to a spectrum of pathogens, including bacteria, fungi, and viruses. Our results suggest a highly ranked regulatory role for NO in SA-, JA-, and/or ET-dependent pathways that lead to disease resistance.