Mutants of produced by ion beam irradiation with an improved ability to uptake and assimilate atmospheric nitrogen dioxide

Takahashi, Misa*; Kohama, S.*; Shigeto, Jun*; Hase, Yoshihiro; Tanaka, Atsushi; Morikawa, Hiromichi*

Production of novel mutants with a high ability to mitigate pollutants is important for phytoremediation. We investigated the use of ion beam irradiation to produce mutants of L. with an improved ability to mitigate atmospheric (NO). More than 25,000 shoot explants were irradiated with ion beams, from which 263 independent plant lines were obtained. The plants were analyzed for NO uptake by fumigation with 1 ppm N-labeled NO, followed by mass spectrometric analysis. The mean NO uptake values of each lines differed over a 110-fold range. Propagation was attempted using cuttings from 44 lines showing the greatest NO uptake; in total, 15 lines were propagated. Two of the 15 lines showed a mean NO uptake 1.7- to 1.8-fold greater than that of the wild-type. This increase in NO uptake was heritable in both lines; their progenies showed a significantly greater ability to take up and assimilate NO than did the wild-type. RAPD analysis demonstrated DNA variation between the progeny plants and the wild type, suggesting that the progeny were true mutants. These mutants of may prove useful in mitigating atmospheric NO.