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The purpose of this research was to obtain recombinant violaxanthin de-epoxidases (VDEs) from two species. The first one was VDE of Arabidopsis thaliana (L.) Heynh. (WT Columbia strain) (AtVDE) which in vivo catalyzes conversion of violaxanthin (Vx) to zeaxanthin (Zx) via anteraxanthin (Ax). The
Violaxanthin de-epoxidase (VDE) is localized in the thylakoid lumen and catalyzes the de-epoxidation of violaxanthin to form antheraxanthin and zeaxanthin. VDE is predicted to be a lipocalin protein with a central barrel structure flanked by a cysteine-rich N-terminal domain and a glutamate-rich
The photosynthetic apparatus of higher plants acclimates to irradiance. Among the features which are changing is the pool size of the pigments belonging to the violaxanthin cycle, in which zeaxanthin is formed. In high light grown leaves, the violaxanthin cycle pool size is up to five times larger
Chlorophyll triplet excited states are by-products of photosynthetic processes that can indirectly harm biological membranes by forming highly reactive oxygen species. A crucial photoprotective mechanism evolved by plants to counter this threat involves the triplet energy transfer from chlorophylls
This study compares Photosystem II (PS II) chlorophyll (Chl) a fluorescence yield changes of Arabidopsis thaliana L. nuclear gene mutants, thoughtfully provided by the authors of Pogson et al. (1998 Proc Natl Acad Sci USA 95: 13324-13329). One single mutant (npq1) inhibits the violaxanthin
In response to conditions of excess light energy, plants induce non-photochemical quenching (NPQ) as a protective mechanism to prevent over reduction of photosystem II and the generation of reactive oxygen species (ROS). The xanthophyll cycle, which contributes significantly to reversible NPQ to
When exposed to saturating light conditions photosynthetic eukaryotes activate the xanthophyll cycle where the carotenoid violaxanthin is converted into zeaxanthin by the enzyme violaxanthin de-epoxidase (VDE). VDE protein sequence includes 13 cysteine residues, 12 of which are strongly conserved in
Plants are often exposed to saturating light conditions, which can lead to oxidative stress. The carotenoid zeaxanthin, synthesized from violaxanthin by Violaxanthin De-Epoxidase (VDE) plays a major role in the protection from excess illumination. VDE activation is triggered by a pH reduction in the
The enzyme violaxanthin de-epoxidase (VxDE) is localized in the thylakoid lumen and catalyzes the de-epoxidation of membrane-bound violaxanthin (Vx) to zeaxanthin. De-epoxidation from the opposite, stroma side of the membrane has been investigated in the npq1 mutant from Arabidopsis thaliana (L.)
Abscisic acid (ABA), a plant hormone synthesized from carotenoids, functions in seed germination and abiotic stress responses. ABA is derived from the cleavage of 9-cis isomers of violaxanthin and neoxanthin, which are oxygenated carotenoids, also called xanthophylls. Although genes encoding enzymes
When light energy absorbed by plants becomes excessive relative to the capacity of photosynthesis, the xanthophyll violaxanthin is reversibly deepoxidized to zeaxanthin (violaxanthin cycle). The protective function of this phenomenon was investigated in a mutant of Arabidopsis thaliana, npq1, that
The light-harvesting chlorophyll a/b complex of photosystem II (LHCII) is able to switch to multiple functions under different light conditions (i.e. harvesting solar energy for photosynthesis and dissipating excess excitation energy for photoprotection). The role of the different carotenoids bound
Violaxanthin de-epoxidase (VDE) activates the dissipation of excessive light energy as heat and protects the photosynthetic apparatus from photo-damage. Here we quantitatively analyzed the expression characteristics of cucumber violaxanthin de-epoxidase (CsVDE) promoter using the 1983 bp upstream
The eukaryotic translation initiation factor (eIF) 4G is a scaffold protein that organizes the assembly of those initiation factors needed to recruit the 40 S ribosomal subunit to an mRNA. Plants, like many eukaryotes, express two eIF4G isoforms. eIFiso4G, one of the isoforms specific to plants, is
To investigate the protective mechanism of violaxanthin de-epoxidase (VDE) zeaxanthin in Cerasus humilis under drought and salt-stress conditions, we cloned the entire cDNA sequence of ChVDE from C. humilis and generated ChVDE-overexpression (OE) and