Fig. 2.

The effect of PsbS on the amount of quenching. $\mathrm{\Delta }{\tau }_{avg,wt,npq\mathit{4}}$ (black) and $\mathrm{\Delta }{\tau }_{avg,npq\mathit{1},npq\mathit{1}npq\mathit{4}}$ (red) are shown. $\mathrm{\Delta }{\tau }_{avg,wt,npq\mathit{4}}$ is calculated by subtracting the average fluorescence lifetime of npq4 from that of wild type, and $\mathrm{\Delta }{\tau }_{avg,npq\mathit{1},npq\mathit{1}npq\mathit{4}}$ is calculated by subtracting the average fluorescence lifetime of npq1 npq4 from that of npq1. When the value of $\mathrm{\Delta }{\tau }_{avg,wt,npq\mathit{4}}$ or $\mathrm{\Delta }{\tau }_{avg,npq\mathit{1},npq\mathit{1}npq\mathit{4}}$ equals 0 (shown by the dashed line), it indicates no difference in average lifetime between the two genotypes. A negative value of $\mathrm{\Delta }{\tau }_{avg,wt,npq\mathit{4}}$ means that wild type has a shorter average fluorescence lifetime, i.e., stronger quenching, than npq4, and a negative value of $\mathrm{\Delta }{\tau }_{avg,npq\mathit{1},npq\mathit{1}npq\mathit{4}}$ means that npq1 has stronger quenching than npq1 npq4. (Insets) Zoomed-in portions of the $\mathrm{\Delta }{\tau }_{avg,wt,npq\mathit{4}}$ and $\mathrm{\Delta }{\tau }_{avg,npq\mathit{1},npq\mathit{1}npq\mathit{4}}$. Leaves were illuminated with 500 μmol photons⋅m⁻²⋅s⁻¹ actinic light.