Cucumber, melon, pumpkin, and squash: are rules of editing in flowering plants chloroplast genes so well known indeed?

The similarities and differences in the chloroplast genes editing patterns of four species from one family (and two genera), which is the first-ever attempt at comparison of such data in closely related species, is discussed. The effective use of the chloroplast genes editing patterns in evolutionary studies, especially in evaluating the kinship between closely related species, is thereby proved. The results indicate that differences in editing patterns between different genera (Cucumis and Cucurbita) exist, and some novel editing sites can be identified even now. However, surprising is the fact of finding editing in the codon for Arg (in flowering plants detected before only in Cuscuta reflexa chloroplast genome, Funk et al.,[Funk H.T., Berg S., Krupinska K., Maier U.G. and Krause K., 2007. Complete DNA sequences of the plastid genomes of two parasitic flowering plants species, Cuscuta reflexa and Cuscuta gronovi. BMC Plant Biol. 7:45, doi: 10.1186/1471-2229-7-45.]), which was believed to have been lost during evolution before the emergence of angiosperms. In addition, the existence of silent editing in plant chloroplasts has been confirmed, and some probable reasons for its presence are pointed out herein.