To optimise the reaction we compared two E. coli K-12 strains (MC4100 and MG1655) and their ompR234 mutants, which overproduce the adhesin curli (PHL644 and PHL628).
Engineered biofilm generation was tested for four E. coli strains: wild type K-12 strains MG1655 and MC4100; and their isogenic ompR234 mutants, which overproduce curli (adhesive protein filaments) and thus accelerate biofilm formation (Vidal et al. 1998).
The eto1-1 mutant, which overproduces ethylene, displayed mild resistance to the inhibitory effects of ABA on seed germination.
Since the BL21∆luxS mutant eliminated endogenous AI-2, the LsrB (BL21∆luxS) mutant, which was overproduced in strain BL21∆luxS, had no AI-2 activity upon denaturation, but could bind to exogenous AI-2.
In addition, the Dam-overproducing luxS mutant strain was not altered in its ability to induce lethality in a mouse model of infection when compared to the parental strain which overproduced Dam.
Surprisingly, overproducing YafQ did not affect cell viability at all (Figure 1A); even in defined M9 medium, in which overproducing the other four toxins caused drastic reductions in cell viability, overproducing YafQ had no effect (Figure S1).
Strains containing plasmid pSU5024 [ 6], which overproduces Eex_R388, were used as controls of poor recipient ability.
This is in agreement with the results of Rate and Greenberg, and is also supported by their finding that plants which overproduce NPR1 exhibit a weaker HR.
Nevertheless, the observation that homoplasmic COXI mutant cells, which do not overproduce ROS, fail to upregulate mitochondrial biogenesis suggests that ROS may play an important role.
Rupp et al.[ 41] found an increase in the transcription level of KNAT1 in the cytokinin-overproducing mutant amp1, which might occur by acting through the activation of KNAT1.
