Localization of Purothionins and Genome Expression in Wheat Plants

The leaves, steins and ears of tetraploidal wheat, Triticumdurum (genomes AABB) harvested two weeks after heading wereanalyzed for purothionins. There were considerable amounts oftwo iso-purothionins (Pu-1 and Pu-2) in the young kernels ofthe ears, but not in the leaves and stems. The amino acid compositionsof Pu-1 and Pu-2 were in good agreement with those of Pu I andPu II from hexaploidal wheat. As diploidal wheat, T. monococcum(genome AA) is known to produce only Pu I Fernandez de Caleyaet al. (1976) Genetics 83: 687], we conclude that the threeiso-purothionins, Pu I, Pu II and Pu III in hexaploidal wheat,T. aestivum (genomes AABBDD), are encoded by the genes of genomesA, B and D, respectively. (Received June 28, 1982; Accepted September 24, 1982)