Recently, a mechanism for the energy-dependent component (qE) of non-photochemical quenching (NPQ), the fundamental photo-protection mechanism in green plants, has been suggested. Replacement of violaxanthin by zeaxanthin in the binding pocket of the major light harvesting complex LHC-II may be sufficient to invoke efficient chlorophyll fluorescence quenching. Our quantum chemical calculations, however, show that the excited state energies of violaxanthin and zeaxanthin are practically identical when their geometry is constrained to the naturally observed structure of violaxanthin in LHC-II. Therefore, since violaxanthin does not quench LHC-II, zeaxanthin should not either. This theoretical finding is nicely in agreement with experimental results obtained by femtosecond spectroscopy on LHC-II complexes containing violaxanthin or zeaxanthin.
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http://dx.doi.org/10.1016/j.jinorgbio.2007.09.013 | DOI Listing |
Commun Biol
December 2024
Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, USA.
Tolerance of chilling dictates the geographical distribution, establishment, and productivity of C crops. Chilling reduces enzyme rate, limiting the sink for the absorbed light energy leading to the need for quick energy dissipation via non-photochemical quenching (NPQ). Here, we characterize NPQ upon chilling in three Miscanthus accessions representing diverse chilling tolerance in C grasses.
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March 2025
Department of Tea Science, College of Food Science, Southwest University, Chongqing 400715, China.
Albino tea cultivars with distinct leaf colors have rarely been used to explore the metabolic mechanism of leaf color formation. Carotenoids and chlorophyll are primary pigments affecting leaf color with differential metabolic mechanisms in albino tea resources. TEM analysis showed that in albino stage, much less chloroplasts with abnormal structure were observed in white and yellow tea leaves, which corresponded to the significant reduction of total chlorophyll, Chl a and Chl b, and increase of Chl a/b, resulting in tea leaves to lose their green color.
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November 2024
Crops Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of Crop Genetic Improvement, Guangzhou 510640, China.
Individual carotenoids provide significant health benefits to humans, and potatoes are recognized as some of the most stable crops, distinguished by their substantial carotenoid content. To elucidate the accumulation patterns of individual carotenoids in potatoes, we quantified the carotenoid content in yellow- and white-fleshed genotypes across five developmental stages using LC-MS/MS. A total of 22 carotenoids were identified in yellow potatoes, whereas 18 were detected in white potatoes.
View Article and Find Full Text PDFNew Phytol
January 2025
Laboratory of Biophysics, Wageningen University, 6708WE, Wageningen, the Netherlands.
Photoprotection in plants includes processes collectively known as nonphotochemical quenching (NPQ), which quench excess excitation-energy in photosystem II. NPQ is triggered by acidification of the thylakoid lumen, which leads to PsbS-protein protonation and violaxanthin de-epoxidase activation, resulting in zeaxanthin accumulation. Despite extensive study, questions persist about the mechanisms of NPQ.
View Article and Find Full Text PDFBMC Plant Biol
October 2024
College of Biological and Agricultural Sciences, Honghe University, Mengzi, 661100, China.
Temperature is an important limiting factor in the counter-seasonal cultivation of pepper. Currently, there are no studies on transcriptomic analysis of 'cold stress memory' in pepper. In this study, in order to understand the mechanism of 'cold stress memory' in pepper (Capsicum annuum L.
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