Glucosinolate and phenylpropanoid biosynthesis are linked by proteasome‐dependent degradation of PAL

• DOI: 10.1111/nph.16108
• Publication Date: 2019-08-13T20:59:00Z
• Authors: Jeong Im Kim; Xuebin Zhang; Pete E. Pascuzzi; Chang‐Jun Liu; Clint Chapple
• Keywords: Phenylpropanoid; Degradation

Summary Plants produce several hundreds of thousands secondary metabolites that are important for adaptation to various environmental conditions. Although different groups synthesized through unique biosynthetic pathways, plants must orchestrate their production simultaneously. Phenylpropanoids and glucosinolates two classes apparently independent pathways. Genetic evidence has revealed the accumulation glucosinolate intermediates limits phenylpropanoid in a Mediator Subunit 5 ( MED 5)‐dependent manner. To elucidate molecular mechanism underlying this process, we analyzed transcriptomes suite Arabidopsis thaliana glucosinolate‐deficient mutants using RNA seq identified misregulated genes rescued by disruption 5. The expression group Kelch Domain F‐Box KFB s) function PAL degradation is affected biosynthesis these s restores deficiency mutants. Our study suggests glucosinolate/phenylpropanoid metabolic crosstalk involves transcriptional regulation initiate enzyme phenylalanine ammonia‐lyase, which catalyzes first step pathway. Nevertheless, mutant remain partially sensitive pathway mutations, suggesting other mechanisms link pathways also exist.