Effect of Spp overproduction from TnRH1 on growth (a) and alginate production (b) in P. fluorescens. Strains included NCIMB10525 (□ in panel a; alginate deficient), NCIMB10525::TnRH1 (■ in panel a; alginate deficient), Pf201 (♢ in panel a; horizontal stripes in panel b), Pf201::TnRH1 (◆ in panel a; solid blue bar in panel b), Pf201ΔalgC::TnKB60 (○ in panel a; diagonal stripes in panel b), and Pf201ΔalgC::TnKB60::TnRH1 (● in panel a; solid red bar in panel b). The growth values represent the means from at least two independent biological replicates, and standard deviations are indicated using error bars.