title: Development of an ion microbeam system for irradiating single plant cell[s].
abstract: An ion microbeam system for irradiating single plant cells was developed to analyze exact biological effects of ion beams. Tobacco BY-2 protoplasts were used as a model of single plant cells. Protoplasts were cultured in thin agarose medium on a specially designed irradiation-vessel, which has a CR-39 nuclear track detector (a 100-micrometer thick sheet). The colony formation rate of unirradiated protoplasts was 22.7 +/- 6.7% (mean +/- SE of 3 different experiments) after a month of culture. Protoplasts were irradiated with programmed numbers of 18.3 MeV/u carbon ions that had been collimated by a 20-micrometer phi micro-aperture. After the irradiation, the positions within the protoplasts that were hit with ions were accurately determined by etching the CR-39 sheet in 13.4M KOH solution at 27 degrees centigrade for 9 h. The hit rate of the carbon ion microbeam, i.e., the percent of the ion particles that hit the protoplast that they were aimed at, was 56.9 +/- 2.4% (mean +/- SE of 7 different replications).
authors.affiliation: Laboratory of Plant Breeding Science, Graduate School of Agriculture, Kyoto Prefectural University, Hangi-cho 1-5, Shimogamo, Sakyo-ku, Kyoto 606-8522 Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yokota
authors.forename: Tomoo
authors.initials: T
authors.lastname: Funayama
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakashita
authors.forename: Seiichi
authors.initials: S
authors.lastname: Wada
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hase
authors.forename: Naoya
authors.initials: N
authors.lastname: Shikazono
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Inoue
mesh_terms: D002244:Carbon; D017357:Cyclotrons / Q000295:instrumentation*; D004867:Equipment Design; D020450:Heavy Ions; D018499:Linear Energy Transfer; D010969:Plastics; D011092:Polyethylene Glycols; D011523:Protoplasts / Q000528:radiation effects*; D011853:Radiobiology / Q000295:instrumentation*; D014026:Nicotiana / Q000166:cytology / Q000528:radiation effects*
chemical_list: D010969:Plastics; C028827:CR 39; D011092:Polyethylene Glycols; D002244:Carbon