title: Gene response in rice plants treated with continuous fog influenced by pH, was similar to that treated with biotic stress.
abstract: BACKGROUND
  Throughout Asia, including Japan, rice plants are cultivated in a wide range of areas from lowlands to highlands and are frequently exposed to fog, including acid fog. Some physiological studies have shown that acid fog can be a stress factor for plants. We analyzed the gene expression profiles of rice plants treated with artificially prepared simulated acid fog (SiAF) or simulated neutral fog (SiNF) for 1 or 7 days.
  
  
  RESULTS
  Microarray analysis results suggested that both the SiAF and the SiNF treatments induced the expression of genes involved in the defense and stress responses in rice plants. Induction of such genes was detected in plants treated with SiAF for 1 day, and the number of induced genes increased in plants treated with SiAF for 7 days. The genes for defense and stress responses were also induced by SiNF for 7 days, although they were not induced by SiNF for 1 day. The gene expression profiles of the SiAF-treated and the SiNF-treated plants were compared to those of plants treated with other stress factors. The comparison revealed that both SiAF and SiNF treatments have similar effects to biotic stresses and ozone stress. The genes encoding NADPH oxidase and germin, which function in apoplasts, were also induced by SiAF, SiNF and biotic stresses.
  
  
  CONCLUSIONS
  These findings suggest that both the SiAF and the SiNF treatments may result in oxidative stress through the apoplastic production of reactive oxygen species.
authors.affiliation: Plant Genome Research Unit, Agrogenomics Research Center, National Institute of Agrobiological Sciences (NIAS), Tsukuba 305-8602, Ibaraki, Japan ; Present address: NARO Hokkaido Agricultural research Center, National Agricultural research Organization, Sapporo 062-8555, Hokkaido, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Satoh
authors.affiliation: Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies (NIES), Tsukuba 305-8506, Ibaraki, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Saji
authors.affiliation: Center for Regional Environmental Research, NIES, Tsukuba 305-8506, Ibaraki, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Ito
authors.affiliation: Center for Regional Environmental Research, NIES, Tsukuba 305-8506, Ibaraki, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shimizu
authors.affiliation: Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies (NIES), Tsukuba 305-8506, Ibaraki, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Saji
authors.affiliation: Plant Genome Research Unit, Agrogenomics Research Center, National Institute of Agrobiological Sciences (NIAS), Tsukuba 305-8602, Ibaraki, Japan.
authors.forename: Shoshi
authors.initials: S
authors.lastname: Kikuchi
keywords: Acid fog; Comparative analysis; Oxidative stress; Rice; Transcriptome