Identification of the first glyphosate transporter by genomic adaptation

Abstract

Summary The soil bacterium Bacillus subtilis can get into contact with growth‐inhibiting substances, which may be of anthropogenic origin. Glyphosate is such a substance serving as a nonselective herbicide. Glyphosate specifically inhibits the 5‐enolpyruvyl‐shikimate‐3‐phosphate (EPSP) synthase, which generates an essential precursor for de novo synthesis of aromatic amino acids in plants, fungi, bacteria and archaea. Inhibition of the EPSP synthase by glyphosate results in depletion of the cellular levels of aromatic amino acids unless the environment provides them. Here, we have assessed the potential of B. subtilis to adapt to glyphosate at the genome level. In contrast to Escherichia coli, which evolves glyphosate resistance by elevating the production and decreasing the glyphosate sensitivity of the EPSP synthase, B. subtilis primarily inactivates the gltT gene encoding the high‐affinity glutamate/aspartate symporter GltT. Further adaptation of the gltT mutants to glyphosate led to the inactivation of the gltP gene encoding the glutamate transporter GltP. Metabolome analyses confirmed that GltT is the major entryway of glyphosate into B. subtilis. GltP, the GltT homologue of E. coli also transports glyphosate into B. subtilis. Finally, we found that GltT is involved in uptake of the herbicide glufosinate, which inhibits the glutamine synthetase.

Resistance to serine in Bacillus subtilis: identification of the serine transporter YbeC and of a metabolic network that links serine and threonine metabolism

“…On the other hand, many permeases have a relatively weak substrate specificity, i.e. they are able to transport multiple amino acids, as shown for BcaP or GltT (Belitsky, 2015; Zaprasis et al ., 2015; Wicke et al ., 2019).…”

Identification of the main glutamine and glutamate transporters inStaphylococcus aureusand their impact on c-di-AMP production

“…However, none of the transporters (AlsT, SAUSA300_0914 and GlnPQ) investigated so far plays a major role in glutamate uptake under our growth conditions. In B. subtilis GltT, belonging to the dicarboxylate/amino acid cation symporter (DAACS) family of proteins, is a major high-affinity Na + -coupled glutamate/aspartate symporter and can also mediate the uptake of glyphosate (Wicke et al ., 2019). An additional two paralogs, DctP and GltP are found in B. subtilis of which GltP has also been shown to be a glutamate transporter (Tolner et al ., 1995).…”

Complete Genome Sequence of the Prototrophic Bacillus subtilis subsp. subtilis Strain SP1

“…The tryptophan prototrophy in the B. subtilis strain SP1 was restored by transforming strain 168 with a DNA fragment containing the wild-type trpC gene of the B. subtilis Marburg strain ATCC 6051 ( 9 ). The simplified medium requirements make strain SP1 suitable for industrial applications like vitamin production ( 9 , 10 ) and basic research like examining the influence of substances that inhibit the biosynthesis of the aromatic amino acids phenylalanine, tryptophan, and tyrosine ( 11 ). To uncover all sequence variations between strain 168 and strain SP1 that might have occurred during the construction of SP1 ( 9 ), we have sequenced its genome.…”