Abstract: The albino and green mutants of Pleioblastus fortunei were derived from ⁶⁰Co γ radiation and long-term proliferation in vitro. To study the ultrastructure of the mutation and gene regulation in the aberrant chloroplasts, we investigated growth characteristics, transmission electronic microscopy data, and copy number of 15 chloroplast-encoded genes and their expression. The albino mutants showed differentiation ability of the bud and adventitious root. The chloroplasts of albino mutants were flawed or their anatomy was incomplete in mesophyll cells. Gene copy number did not differ between the albino and wild-type explants. However, transcription level of most genes was reduced in albino mutants except that the expression of psbA was increased. The color of leaves of the green mutants showed stable inheritance. The chloroplast grana lamella quantity of the green mutants was less than that of the wild type, and the anatomy in the green-sector cells was much looser than that of the wild type. The gene copy number was not higher in green mutants than in wild-type explants, and the expression of most genes, except atpI, in the green mutants seemed to decline compared with that in the wild type. The expression of atpI was higher in green mutants than in the wild type. Moreover, psaA was not expressed in the two kinds of mutants and was only weakly expressed in the wild type.

Key words: chloroplast genes, gene expression, mutant