The entry reaction of the plant shikimate pathway is subjected to highly complex metabolite-mediated regulation

• DOI: 10.1093/plcell/koaa042
• Publication Date: 2021-01-01T04:13:05Z
• Authors: Ryo Yokoyama; Marcos V V de Oli...; Bailey Kleven; Hiroshi A Maeda
• Keywords: Shikimate pathway; Shikimic acid

Abstract The plant shikimate pathway directs bulk carbon flow toward biosynthesis of aromatic amino acids (AAAs, i.e. tyrosine, phenylalanine, and tryptophan) numerous phytochemicals. microbial is feedback inhibited by AAAs at the first enzyme, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DHS). However, generally do not inhibit DHS activities from extracts how plants regulate remains elusive. Here, we characterized recombinant Arabidopsis thaliana DHSs (AthDHSs) found that tyrosine tryptophan AthDHS2, but AthDHS1 or AthDHS3. Mixing AthDHS2 with 3 attenuated its inhibition. AAA phenylpropanoid intermediates chorismate caffeate, respectively, strongly all AthDHSs, while arogenate intermediate counteracted inhibition chorismate. activity in young seedlings, where highly expressed, mature leaves, predominantly expressed. dhs1 dhs3 knockout mutants were hypersensitive to tryptophan, dhs2 was resistant tyrosine-mediated growth also had reduced anthocyanin accumulation under high light stress. These findings reveal complex regulation entry reaction lay foundation for efforts control production diverse natural products plants.