AA	Amino Acids
ABA	Abscisic Acid
AtCPA	Arabidopsis thaliana Cation proton antiporter gene
BraCPA	Brassica rapa Cation proton antiporter gene
BRAD	Brassica database
Cd	Cadmium
Chr(s)	Chromosome(s)
CHX	Cation/H+ exchanger
CPA	Cation proton antiporter
Cr	Chromium
DD	Dispersed duplication
GA3	Gibberellin A3
GRAVY	Grand average of hydropathicity
HM	Heavy metal
HMM	Hidden Markov Model
KEA	K+ efflux antiporter
MCScanX	Multiple Collinearity Scan toolkit
MeJA	Methyl Jasmonate
MEME	Multiple Em for Motif Elicitation
MW	Molecular weight
NHX	Na+/H+ exchanger family
NJ	Neigbor-joining
ORF	Open reading frame
Pb	Lead
PD	Proximal duplicatio
pI	Theoretical isoelectric point
PlantDGD	Plant Duplicate Gene Database
RGD	Radish Genome Database
RPKM	Reads per kilobase per million reads
RsCPA	Raphanus sativus Cation proton antiporter gene
RT–qPCR	Real-Time Quantitative Polymerase Chain Reaction
TD	Tandem duplication
TMHMM	TransMembrane prediction was analyzed by Hidden Markov Models
TRD	Transposed duplication
TYMV	Turnip yellow mosaic virus
UTR	Untranslated region
VIGS	Virus-induced gene silencing
WGD	Whole-genome duplication
WT	Wide type