It occurs before the three hydroxylation steps in prokaryotes, whereas in eukaryotes, decarboxylation occurs after a hydroxylation step and an O -methylation step. Such an effect was not observed in the tocopherol-deficient vte2 mutant that contains normal levels of plastochromanol Carotenoids are considered to be the first line of defense against 1 O 2 toxicity because of their high efficiency of 1 O 2 quenching and their localization in close proximity with the chlorophyll molecules in the light-harvesting complexes and the reaction centers of the photosystems 4
For each compound, values were normalized to the control value at time 0. Genes encoding HSTs have only reported in C. Moreover, those changes in plastoquinone-9 content appeared to follow the changes in PSII photochemical efficiency, with PSII photoinhibition plastoqunione accompanied by plats loss of plastoquinone-9 and PSII recovery being paralleled by increasing concentrations of plastoquinone The reduction state of plastoquinone-9 increased very slightly in the SPS1oex leaves Supplementary Fig. Genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis in photosynthetic organisms. Amino acids are not only metabolized in peroxisomes but also broken down in mitochondria, which provide carbon skeletons for biosynthesis of many important compounds, such as vitamins, amino acids, and lipids Sweetlove et al.It is concluded that the plant leaf Golgi membranes contain the enzymes for both UQ and PQ biosynthesis and that a specific transport and. Official Full-Text Paper (PDF): Plant tolerance to excess light energy and photooxidative damage relies on plastoquinone biosynthesis. Official Full-Text Paper (PDF): Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering.