DTA

Digital Theses Archive

 

Tesi etd-10062023-201505

Type of thesis
Corso Ordinario Secondo Livello
Author
GHIGI, ANDREA
URN
etd-10062023-201505
Title
The regulation of ascorbic acid by blue light receptors
Structure
Cl. Sc. Sperimentali - Agraria
Course
SCIENZE AGRARIE E BIOTECNOLOGIE - SCIENZE AGRARIE E BIOTECNOLOGIE
Committee
Tutor Prof. SEBASTIANI, LUCA
Membro Prof.ssa GIUNTOLI, BEATRICE
Membro Prof. FERNIE, ALISDAIR ROBERT
Membro Dott.ssa PELLEGRINO, ELISA
Membro Prof. PERATA, PIERDOMENICO
Membro Prof. TONUTTI, PIETRO
Membro Prof.ssa MENSUALI, ANNA
Keywords
  • ascorbic acid
  • cryptochromes
  • high light acclimation
  • PAS-LOV protein
Exam session start date
15/12/2023;
Availability
parziale
Abstract
Ascorbic acid, or vitamin C, is one of the most abundant molecules in plant cells and plays an essential role in multiple processes, including ROS scavenging, cell signalling and enzyme catalysis. Here, we aimed at identifying and characterizing the genes which are involved in the regulation of ascorbic acid levels in Arabidopsis thaliana. For this purpose, ascorbic acid concentration in the leaves of 300 different accessions of A. thaliana was measured by HPLC and a genome-wide association study (GWAS) was performed. Some of the most statistically significant polymorphisms were located in the gene sequence of a putative blue light receptor. Two distinct splice variants, PLPA and PLPB, were shown to interact in vitro and in vivo with VITAMIN C DEFECTIVE 2 (VTC2), a critical enzyme involved in ascorbic acid biosynthesis. Furthermore, plp knockout mutants were characterized by 1.5- to 1.7- fold higher ascorbate levels than wild type. Additionally, the knockout mutant of the blue light receptor CRYPTOCHROME1 and CRYPTOCHROME2 displayed an increase and a decrease in ascorbate levels, respectively. In conclusion, our results collectively indicate that PLP and other blue light receptors play a critical role in the regulation of ascorbate levels, which is a signature response of high light acclimation.
Files