Table 1 List of the bacteria and plasmids used in this study.

E. coli

Top10 mcrA (mrr-hsdRMS-mcrBC) 80lacZM15 lacX74 recA1 araD139(araleu)7697galU galK rpsL(Strr) endA1 nupG

Invitrogen

BL21(DE3)

F ompT hsd SB(rB mB) dcm gal(DE3)

Novagen

BL/pET-28a

BL21(DE3) with pET-28a; Km^r

This study

BL/pET-hfq

BL21(DE3) with pET-hfq; Km^r

This study

Pf-5

Rhizosphere isolate; Ap^r

32

PfΔhfq

hfq derivative of Pf-5; Ap^r

This study

PfΔrsmY

rsmY derivative of Pf-5; Ap^r

This study

PfΔhfqΔrsmY

Hfq and rsmY derivative of Pf-5; Ap^r

This study

Pf-5F3

pJQ003 conjugated into Pf-5; Gm^r

This study

Pf-5F4

pJQ004 conjugated into Pf-5; Gm^r

This study

PfΔhfqF3

pJQ003 conjugated into PfΔhfq; Gm^r

This study

PfΔhfqF4

pJQ004 conjugated into PfΔhfq; Gm^r

This study

PfΔrsmYF3

pJQ003 conjugated into PfΔrsmY; Gm^r

This study

PfΔrsmYF4

pJQ004 conjugated into PfΔrsmY; Gm^r

This study

PfΔhfqΔrsmYF3

pJQ003 conjugated into PfΔhfqΔrsmY; Gm^r

This study

PfΔhfqΔrsmYF4

pJQ004 conjugated into PfΔhfqΔrsmY; Gm^r

This study

Triparental mating, pRK2073

Helper plasmid for triparental mating;Sp^r

33

pJQ200SK

Suicide vector with sacB counterselectable marker used for homologous recombination; Gm^r

34

pJQΔhfq

pJQ200SK carrying a 1.9-kb XbaI/HindIII insert with a deletion in the coding region of hfq; Gm^r

This study

pJQΔrsmY

pJQ200SK carrying a 1.7-kb XbaI/HindIII insert with a deletion in the coding region of rsmY; Gm^r

This study

pBBR1MCS-5

Broad-host-range vector; Gm^r

35

pBBR1Km

NcoI-BgIII-digested kanamycin resistance cassettesubcloned in pBBR1MCS-5 digested with the same endonucleases

This study

pBBRKm

pBBR1Km with a 1,280-bp BamHI/XbaI fragment harboring lacI ^q-P _lac ; Km^r

This study

pBBR-hfq

pBBR1MCS-5 with a 547-bp BamHI/HindIII fragment harboring the codingregion of hfq; Km^r

This study

pBBR-rsmX

pBBR1MCS-5 carrying a 183-bp BamHI/HindIII fragment harboring the coding region of rsmX; Km^r

This study

pBBR-rsmY

pBBR1MCS-5 carrying a 135-bp BamHI/HindIII fragment harboring the coding region of rsmY; Km^r

This study

pBBR-rsmZ

pBBR1MCS-5 carrying a 145-bp BamHI/HindIII fragment harboring the coding region of rsmZ; Km^r

This study

pBBRK-hfq

pBBRKm with a 547-bp BamHI/HindIII fragment harboring the coding region of hfq; Km^r

This study

pBBRK-rsmX

pBBRKm carrying a 183-bp BamHI/HindIII fragment harboring the coding region of rsmX; Km^r

This study

pBBRK-rsmY

pBBRKm carrying a 135-bp BamHI/HindIII fragment harboring the coding region of rsmY; Km^r

This study

pBBRK-rsmZ

pBBRKm carrying a 145-bp BamHI/HindIII fragment harboring the coding region of rsmZ; Km^r

This study

pET-28a

Expression vector carrying an N-terminal His tag thrombin-T7 tag configuration plus an optional C-terminal His tag sequence; Km^r

Novagen

pET-hfq

pET-28a carrying a 305-bp NdeI-HindIII fragment harboring the coding region of hfq; Km^r

This study

pBBR01

pBBR1MCS-5 derivative with a translational lipA′-′lacZ fusion; Gm^r

This study

pBBR02

pBBR1MCS-5 derivative with a transcriptional lipA-lacZ fusion; Gm^r

This study

pBBR03

pBBR1MCS-5 derivative with a translational rsmA′-′lacZ fusion; Gm^r

This study

pBBR04

pBBR1MCS-5 derivative with a translational rsmE′-′lacZ fusion; Gm^r

This study

pBBR05

pBBR1MCS-5 derivative with a translational rsmY′-′lacZ fusion; Gm^r

This study

pBBR06

pBBR1MCS-5 derivative with a translational rsmZ′-′lacZ fusion; Gm^r

This study

pBBR07

pBBR1MCS-5 derivative with a translational phrs′-′lacZ fusion; Gm^r

This study

pJQ003

pJQ200SK derivative with a translational lipA′-′lacZ fusion; Gm^r

This study

pJQ004

pJQ200SK derivative with a transcriptional lipA-lacZ fusion; Gm^r

This study