Associate Professor, Biology
Affiliate, Molecular and Cellular Biochemistry
Myers Hall 330
Lab website
Photosynthesis is of critical importance, as it provides the energy that drives food, feedstock and biofuel production and mitigates climate change. The balance of light harvesting and dissipation by photosynthetic organisms is key for protection against photodamage and its manipulation can lead to gains in biomass. My group seeks to understand how this balance is established by studying the molecular mechanisms of photoprotection. We use genetics, molecular biology, biochemistry, structural biology and biophysics to discover new biological regulation of energy dissipation and its photophysical properties. Energy dissipation through processes referred to as nonphotochemical quenching of chlorophyll fluorescence protects photosynthetic organisms from excess light. Previously in Arabidopsis, we have identified factors which modulate a sustained form of energy dissipation that we termed qH. Its activation requires the plastid lipocalin (LCNP) whereas suppressor of quenching1 (SOQ1) inhibits LCNP and a short-chain dehydrogenase reductase is involved in the relaxation of qH (ROQH1). Strikingly qH-deficient plants bleach under excess light while constitutive activation of qH causes severe light-limitation and a stunted phenotype. We are investigating the function of these factors, and newly identified ones, in repressing, turning on or off qH at the transcriptional, structural and post-translational levels. Specifically our research advances knowledge of: 1) protein translocation, redox regulation and post translational regulation within the thylakoid lumen, 2) light harvesting protein structure-function, membrane protein insertion and remodeling, and 3) underexplored chloroplast pathways including trans-thylakoid thiol-metabolism and sugar-mediated feedback on photoprotection.
Genomics and Bioinformatics
Plant Molecular Biology
Supramolecular Complexes
Chemical + Physical Biology
Bru P, Steen CJ, Park S, Amstutz CL, Sylak-Glassman EJ, Lam L, Fekete A, Mueller MJ, Longoni F, Fleming GR, Niyogi KK & Malnoë A* (2022) The major trimeric antenna complexes serve as a site for qH-energy dissipation in plants. Journal of Biological Chemistry 298(11):102519
Yu G, Hao J, Pan X, Shi L, Zhang Y, Wang J, Fan H, Xiao Y, Yang F, Lou J, Chang W, Malnoë A* & Li M* (2022) Structure of Arabidopsis SOQ1 lumenal region unveils C-terminal domain essential for negative regulation of photoprotective qH. Nature Plants 8:840–855
Amstutz C, Fristedt R, Schultink A, Merchant S, Niyogi KK*, & Malnoë A* (2020) An atypical short chain dehydrogenase/reductase functions in the relaxation of photoprotective qH in Arabidopsis. Nature Plants 6:154–166
Malnoë A*, Schultink A, Shahrasbi S, Rumeau D, Havaux M, & Niyogi KK* (2018) The plastid lipocalin LCNP is required for sustained photoprotective energy dissipation in Arabidopsis. The Plant Cell 30:196-208
Malnoë A, Wollman FA, de Vitry C, & Rappaport F (2011) Photosynthetic growth despite a broken Q-cycle. Nature Communications 2:301-306
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