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Comparative study on the evolution of chloroplast ribosomal 5 S RNA of a living fossil plant, Cycas revoluta Thunb
Author(s) -
Zhou Xue-qiong,
Liu Wang-yi,
Wang Ming-qi
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)81228-6
Subject(s) - chloroplast , biology , ribosomal rna , botany , homology (biology) , 18s ribosomal rna , green algae , phylogenetic tree , algae , genetics , gene
The complete nucleotide sequence of Cycas revoluta Thunb chloroplast 5 S rRNA was determined. It consists of 122 nucleotides. This is the only known 5 S rRNA sequence in Gymnospermae. It is highly homologous with chloroplast 5 S rRNA of higher plants (92–97%), but less homologous (about 54%) with those of lower plants. There is however 67% homology between Cycas and a procaryote A. nidulans . The chloroplast 5 S rRNAs of Angiospermae are nearly identical with each other (95–97%). S. oligorhize and L. minor have 100% homology among themselves. We have constructed a phylogenic tree of 5 S rRNA sequences from fifteen plant chloroplasts. The result suggests that the emergence of algae occurred at an early stage of plant chloroplast evolution and that green plants originated from green algae. This is in agreement with the classical view and other theories of molecular evolution. However there is no common ancestor in the case of Bryophyta and ferns. Among the Angiospermae, a precise evolutionary process cannot be deduced because the K nuc values among the species are very close to each other.