Gl. Galloway et al., PHYLOGENETIC UTILITY OF THE NUCLEAR GENE ARGININE DECARBOXYLASE - AN EXAMPLE FROM BRASSICACEAE, Molecular biology and evolution, 15(10), 1998, pp. 1312-1320
Arginine decarboxylase (ADC) is an important enzyme in the production
of putrescine and polyamines in plants. It is encoded by a single or l
ow-copy nuclear gene that lacks introns in sequences studied to date.
The rate of Ade amino acid sequence evolution is similar to that of nd
hF for the angiosperm family studied. Highly conserved regions provide
several target sites for PCR priming and sequencing and aid in nucleo
tide and amino acid sequence alignment across a range of taxonomic lev
els, while a variable region provides an increased number of potential
ly informative characters relative to ndhF for the taxa surveyed. The
utility of the Ade gene in plant molecular systematic studies is demon
strated by analysis of its partial nucleotide sequences obtained from
13 representatives of Brassicaceae and 3 outgroup taxa, 2 from the mus
tard oil clade (order Capparales) and 1 from the related order Malvale
s. Two copies of the Adc gene, Adc1 and Adc2, are found in all members
of the Brassicaceae studied to date except the basal genus Aethionema
. The resulting Ade gene tree provides robust phylogenetic data regard
ing relationships within the complex mustard family, as well as indepe
ndent support for proposed tribal realignments based on other molecula
r data sets such as those from chloroplast DNA.