Previous transient absorption spectroscopy experiments to elucidate the biophysical mechanism(s) of NPQ were complicated by the occurrence of exciton-exciton annihilation. Former Ph.D. student Dhruv Patel-Tupper and Fleming lab Ph.D. students Tsung-Yen Lee and Lam Lam co-led this study published in PNAS in which they were able to obtain annihilation-free signals showing that excitation energy transfer from chlorophyll to zeaxanthin is indeed associated with NPQ in Nicotiana benthamiana thylakoids.