Methionine sulfoximine--resistant mutants of tobacco.

Selecting mutants from populations of haploid plant cells cultured in vitro may provide a rapid method for recovering agriculturally useful variants. Mutants of Nicotiana tabacum were recovered which were resistant to methionine sulfoximine, an analog structurally similar to methionine. Induction of chlorosis was prevented or less evident in mutant plants that were inoculated withPseudomonas tabaci, a bacterial pathogen which produces a toxin that is a structural analog of methioning. Several mutants show a specific increase in the level of free methionine.