Table S2.

Oligonucleotide primers used in this study

Primer name	Primer sequence	Target and purpose
pQBR57_TrfA_F	AGACGTGACCCTGGAATTGG	pQBR57_0001, identifying plasmid presence
pQBR57_TrfA_R	TGGTCGGATTTGAACCGTCG
pQBR57_UvrD_F	CTTCGAAGCACACCTGATG	pQBR57_0131, identifying plasmid presence
pQBR57_UvrD_R	TGAAGGTATTGGCTGAAAGG
Tn5042_MerA_F	TGCAAGACACCCCCTATTGGAC	merA, identifying presence of mercury reductase
Tn5042_MerA_R	TTCGGCGACCAGCTTGATGAAC
KT2440_F	ATGGCAATGTCCGCAATCC	ISPpu10, identifying P. putida KT2440 (48)
KT2440_R	CGGAAGCCTCTGAACACG
SBW25_F	ACTGCATTCAAAACTGACTGA	16S DNA, identifying P. fluorescens SBW25 (49)
SBW25_R	AATCACACCGTGGTAACCG

All PCRs were performed with the following thermocycling program: 5 min at 95 °C, followed by 30 cycles of 30 s at 95 °C, 30 s at 58 °C, and 1 min at 72 °C, followed by final extension for 5 min at 72 °C.