Transparent testa phenotype

In order to compare mutation frequency induced by 220-MeV C ions with that by low-LET radiation (electrons), Arabidopsis visible phenotype loci were chosen as follows transparent testa tt) whose seed coat is transparent because of lack of pigment glaborous gl), which have no hair on their leaves and stems and long hypocotyl hy) whose hypocotyl is longer than that of the wild type in the light condition. Mutation frequencies of tt, gl, and hy induced by carbon ions were 8- to 34-fold higher than those by electrons (Table 2). In this study, irradiation doses for the induction of mutation were determined from the RBE of carbon ions compared with that of electrons on the survival of plants, which was approximately 5. Both doses are at three-quarters of the shoulder dose of each survival curve [104]. 

Carey, C.C. et al.. Mutations in the pale aleurone color 1 regulatory gene of the Zea mays anthocyanin pathway have distinct phenotypes relative to the functionally similar TRANSPARENT TESTA GLABRAl gene in Arabidopsis thaliana. Plant Cell, 16, 450, 2004. 

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