skip to main content


Title: Down-regulation of kelch domain-containing F-box protein in Arabidopsis enhances the production of (poly)phenols and tolerance to ultraviolet radiation

Phenylpropanoid biosynthesis in plants engenders myriad phenolics with diverse biological functions. Phenylalanine ammonia-lyase (PAL) is the first committed enzyme in the pathway, directing primary metabolic flux into a phenylpropanoid branch. Previously, we demonstrated that the Arabidopsis Kelch-domain containing F-box proteins, AtKFB01, -20, and -50, function as the negative regulators controlling phenylpropanoid biosynthesis via mediating PAL’s ubiquitination and subsequent degradation. Here, we reveal that Arabidopsis KFB39, a close homolog of AtKFB50, also interacts physically with PAL isozymes and modulates PALs' stability and activity. Disturbing the expression of KFB39 reciprocally affects the accumulation/deposition of a set of phenylpropanoid end products, suggesting that KFB39 is an additional post-translational regulator responsible for the turnover of PAL and negatively controlling phenylpropanoid biosynthesis. Furthermore, we discover that exposure of Arabidopsis to UV-B radiation suppresses the expression of all four KFB genes while inducing the transcription of PAL isogenes; these data suggest that Arabidopsis consolidates both transcriptional and post-translational regulation mechanisms to maximize its responses to UV stress. Simultaneous down-regulation of all four identified KFBs significantly enhances the production of (poly)phenols and the plant’s tolerance to UV irradiation. This study offers a biotechnological approach for engineering the production of useful phenolic chemicals and for increasing a plant’smore » resistance to environmental stress.« less
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States); Shanxi Agriculture Univ., Taigu, Shanxi (People's Republic of China); Stony Brook Univ., Stony Brook, NY (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0032-0889; R&D Project: BO-169; KC0304020
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Plant Physiology (Bethesda)
Additional Journal Information:
Journal Name: Plant Physiology (Bethesda); Journal Volume: 167; Journal Issue: 2; Journal ID: ISSN 0032-0889
American Society of Plant Biologists
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; biochemical processes and macromolecular structures
OSTI Identifier: