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Tobacco plants were transformed by Agrobacterium rhizogenes infection during their evolution
Author(s) -
Suzuki Kenji,
Yamashita Ichiro,
Tanaka Nobukazu
Publication year - 2002
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2002.01468.x
Subject(s) - agrobacterium , nicotiana tabacum , biology , nicotiana , dna , gene , genetics , genome , plasmid , phylogenetic tree , nuclear dna , botany , microbiology and biotechnology , solanaceae , transformation (genetics) , mitochondrial dna
Summary We discovered that the origin of cT‐DNA in the genome of wild‐type Nicotiana glauca is the T‐DNA of the mikimopine‐type Ri plasmid (pRi) harbored in Agrobacterium rhizogenes . The cT‐DNA was inserted into the genomic DNA of N. glauca from the position corresponding to the right border of mikimopine‐type pRi. The cT‐DNA contained two mikimopine synthase gene ( mis ) homologs, Ng mis L and Ng mis R, both of which were transcribed at low level in all N. glauca organs. NgMisR protein expressed in Escherichia coli has preserved Mis activity, which converts l ‐histidine and α‐ketoglutaric acid to mikimopine. The mis homolog was also found in the genome of three other Nicotiana species: N. tomentosa , N. tomentosiformis , and N. tabacum ; however, the site of insertion differed from that in N. glauca , suggesting that A. rhizogenes harboring mikimopine‐type pRi independently infected the ancestors of some Nicotiana plants. This is the first clear evidence of a host–parasite relationship during the early evolution of Nicotiana plants. We propose that a new phylogenetic approach using opine type cT‐DNA is applicable for presuming divergence in the genus Nicotiana .