Molecular mechanisms of generation for nitric oxide and reactive oxygen species, and role of the radical burst in plant immunity

• Published in: Molecules and cells Vol. 28; no. 4; pp. 321 - 330
• Main Authors: Yoshioka, Hirofumi, Nagoya University, Chikusa, Nagoya, Japan, Asai, Shuta, Nagoya University, Chikusa, Nagoya, Japan, Yoshioka, Miki, Nagoya University, Chikusa, Nagoya, Japan, Kobayashi, Michie, National Institute of Agrobiological Sciences, Tsukuba, Japan
• Format: Journal Article
• Language: English
• Published: Springer Korean Society for Molecular and Cellular Biology 01.10.2009; 한국분자세포생물학회
• Subjects: Biochemistry; Biomedical and Life Sciences; Biomedicine; Biotechnology; CDPK; Cell Biology; Life Sciences; MAPK; Minireview; NADPH oxidase; NITRIC OXIDE; Nitric Oxide - metabolism; OXIDO NITRICO; OXYDE NITRIQUE; Plants - immunology; reactive oxygen species; Reactive Oxygen Species - metabolism; Respiratory Burst - immunology; 생물학; nitric oxide; CDPK; MAPK; NADPH oxidase; reactive oxygen species
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-009-0156-2

Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and H₂O₂ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.