Förster resonance energy transfer (FRET) rate constants were calculated based on FRET theory (Ref.1). The FRET rate constants (kFRET) were defined as kFRET = (C∙𝜅2)/(n4∙R6), where C is a factor calculated from spectral overlap integral between the two Chls, 𝜅2 is the dipole orientation factor, n is the refractive index and R is the distance between two Chls. The applied C values for Chl a→Chl a, Chl a→Chl b, Chl b→Chl a and Chl b→Chl b were 32.26, 1.11, 9.61 and 14.45, respectively, which were estimated in Gradinaru et al. (Ref.2). 𝜅2 was defined as 𝜅2 = [ûD∙ûA−3∙(ûD∙R̂DA)∙(ûA∙R̂DA)]2, where ûD and ûA are the dipole unit vectors of donor and acceptor Chls driven from the vectors from the coordinates of NB and ND atoms, and R̂DA is the unit vector of the vector from the magnesium of the donor Chl to the magnesium of the acceptor Chl. The value of n was 1.55 taken from Gradinaru et al. (Ref.2). R was taken from the distance between central magnesium atoms of two Chls. References 1. Mazor, Y., Borovikova, A., Caspy, I. & Nelson, N. Structure of the plant photosystem I supercomplex at 2.6 Å resolution. Nat. Plants 3, 17014 (2017). 2. Gradinaru, C. C., Ozdemir, S., Gülen, D., van Stokkum, I. H., van Grondelle, R., & van Amerongen, H. The flow of excitation energy in LHCII monomers: implications for the structural model of the major plant antenna. Biophys. J. 75, 3064-3077 (1998).