Many of the photosynthetic genes are conserved among all higher plants, indicating that there is strong selective pressure to maintain the genes of each protein. However, mutants of these genes often lack visible growth phenotypes, suggesting that they are important only under certain conditions or have overlapping functions. To assess the importance of specific genes encoding the light-harvesting complex (LHC) proteins for the survival of the plant in the natural environment, we have combined two different scientific traditions by using an ecological fitness assay on a set of genetically modified Arabidopsis plants with differing LHC protein contents. The fitness of all of the LHC-deficient plants was reduced in some of the growth environments, supporting the hypothesis that each of the genes has been conserved because they provide ecological flexibility, which is of great adaptive value given the highly variable conditions encountered in nature.
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http://dx.doi.org/10.1104/pp.103.033324 | DOI Listing |
J Phys Chem Lett
December 2024
Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
Light-harvesting complex II (LHCII), the most abundant membrane protein in photosystem II, plays dual roles, i.e., efficient light harvesting and energy transfer to the reaction center under low light conditions and dissipating excess energy as heat to prevent photodamage under high irradiation conditions.
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigo-Naka, Myodaiji, Okazaki, Aichi 444-8585, Japan.
The light-harvesting complex II (LHCII) in green plants exhibits highly efficient excitation energy transfer (EET). A comprehensive understanding of the EET mechanism in LHCII requires quantum chemical, molecular dynamics (MD), and statistical mechanics calculations that can adequately describe pigment molecules in heterogeneous environments. Herein, we develop MD simulation parameters that accurately reproduce the quantum mechanical/molecular mechanical energies of both the ground and excited states of all chlorophyll (Chl) molecules in membrane embedded LHCII.
View Article and Find Full Text PDFCommun Biol
December 2024
Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Purple phototrophic bacteria produce two kinds of light-harvesting complexes that function to capture and transmit solar energy: the core antenna (LH1) and the peripheral antenna (LH2). The apoproteins of these antennas, encoded respectively by the genes pufBA and pucBA within and outside the photosynthetic gene cluster, respectively, exhibit conserved amino acid sequences and structural topologies suggesting they were derived from a shared ancestor. Here we present the structures of two photosynthetic complexes from Roseospirillum (Rss.
View Article and Find Full Text PDFJ Phys Chem B
December 2024
Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy.
Light-harvesting complexes (LHCs) play a critical role in modulating energy flux within photosynthetic organisms in response to fluctuating light. Under high light conditions, they activate quenching mechanisms to mitigate photodamage. Despite their importance, the molecular mechanisms underlying these photoprotective processes remain incomplete.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
Department of Chemistry, IIT Jodhpur, Jodhpur, Rajasthan 342037, India.
The plant thylakoid membrane hosting the light-harvesting complex (LHCII) is the site of oxygenic photosynthesis. Contrary to the earlier consensus of a protein-driven single lamellar phase of the thylakoid, despite containing 40% non-bilayer-forming lipids, recent experiments confirm the polymorphic state of the functional thylakoid. What, then, is the origin of this polymorphism and what factors control it? The current Letter addresses the question using a total of 617.
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