Focal correlations of
previous analyses are not robust to new data.
Points with black outlines are from ref (6), and dashed gray lines represent the best fit
to FI Rubisco data. Histograms for kcat,C, SC/O, and KC are plotted on parallel axes. Panel A plots kcat,C against SC/O. kcat,C and SC/O correlate with
an R of approximately −0.6 among FI Rubiscos
as compared to ≈0.9 previously.5,6 The 95% confidence
intervals are (−4.0, −2.0) for the fit exponent and
(3 × 104, 2 × 108) for the prefactor
(slope and intercept on a log–log scale, respectively), indicating
that the form of kcat,C–SC/O correlation is very uncertain. Notably, SC/O displays very limited variation overall
and especially within physiological groupings with sufficient data.
Median SC/O values are 177 for red algae
(σ* = 1.2; N = 6), 98 for C3 plants
(σ* = 1.1; N = 162), 80 for C4 plants
(σ* = 1.1; N = 35), and 48 for cyanobacteria
(σ* = 1.1; N = 16). Panel B plots kcat,C against KC. Here, the R is ≈0.5 as compared to ≈0.9 previously.6 This fit is more robust, with 95% confidence
intervals of (0.3, 0.5) and (0.8, 1.5) for the fit exponent and prefactor,
respectively.