Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Mar 17.
doi: 10.1111/tpj.14751. Online ahead of print.

Light Regulation of Light-Harvesting Antenna Size Substantially Enhances Photosynthetic Efficiency and Biomass Yield in Green Algae


Light Regulation of Light-Harvesting Antenna Size Substantially Enhances Photosynthetic Efficiency and Biomass Yield in Green Algae

Sangeeta Negi et al. Plant J. .


One of the major factors limiting biomass productivity in algae is the low thermodynamic efficiency of photosynthesis. The greatest thermodynamic inefficiencies in photosynthesis occur during the conversion of light into chemical energy. At full sunlight the light-harvesting antenna captures photons at a rate nearly 10 times faster than the rate-limiting step in photosynthetic electron transport. Excess captured energy is dissipated by non-productive pathways including the production of reactive oxygen species. Substantial improvements in photosynthetic efficiency have been achieved by reducing the optical cross-section of the light-harvesting antenna by selectively reducing chlorophyll b levels and peripheral light-harvesting complex subunits. Smaller light-harvesting antenna, however, may not exhibit optimal photosynthetic performance in low or fluctuating light environments. We describe a translational control system to dynamically adjust light-harvesting antenna sizes for enhanced photosynthetic performance. By expressing a chlorophyllide a oxygenase (CAO) gene having a 5' mRNA extension encoding a Nab1 translational repressor binding site in a CAO knockout line it was possible to continuously alter chlorophyll b levels and correspondingly light-harvesting antenna sizes by light-activated Nab1 repression of CAO expression as a function of growth light intensity. Significantly, algae having light-regulated antenna sizes had substantially higher photosynthetic rates and two-fold greater biomass productivity than the parental wild-type strains as well as near wild-type ability to carry out state transitions and non-photochemical quenching. These results have broad implications for enhanced algae and plant biomass productivity.

Keywords: Chlamydomonas; algae; biofuels; chlorophyll; light-harvesting antenna; non-photochemical quenching; photosynthesis; thylakoid.

Similar articles

See all similar articles


    1. Allen, J.F. and Forsberg, J. (2001) Molecular recognition in thylakoid structure and function. Trends Plant Sci. 6, 317-326.
    1. Arnon, D.I. (1949) Copper enzymes in isolated chloroplasts. Polyphenoloxidase in Beta Vulgaris. Plant Physiol. 24, 1-15.
    1. Ballottari, M., Mozzo, M., Croce, R., Morosinotto, T. and Bassi, R. (2009) Occupancy and functional architecture of the pigment binding sites of photosystem II antenna complex Lhcb5. J. Biol. Chem. 284, 8103-8113.
    1. Barber, J. and Chow, W.S. (1979) A mechanism for controlling the stacking and unstacking of chloroplast thylakoid membranes. FEBS Lett. 105, 5-10.
    1. Beckmann, J., Lehr, F., Finazzi, G., Hankamer, B., Posten, C., Wobbe, L. and Kruse, O. (2009) Improvement of light to biomass conversion by de-regulation of light-harvesting protein translation in Chlamydomonas reinhardtii. J. Biotechnol. 142, 70-77.

LinkOut - more resources