Figure 7.

Relation between epidermal screening and UV absorption of phenolics. Data of individual leaves are shown. In A and B, we plot epidermal transmittance for UV-A radiation (T_UV-A) against transmittance of extracted leaf phenolics at 360 nm (T₃₆₀), and epidermal UV-B transmittance (T_UV-B) against transmittance of extracted leaf phenolics at 314 nm (T₃₁₄), respectively (extracted phenolics correspond to peaks 1–10 in Fig. 2). In A and B, the bold line results from linear regression to solid circles, that is for T₃₆₀ > 3% and T₃₁₄ > 3%. In A and B, coefficients of determinations are r² = 0.874 and r² = 0.750, and equations resulting from regression analyses are T_UV-A = 11 + 0.72 × T₃₆₀ and T_UV-B = 8 + 1.22 × T₃₆₀, respectively. White circles (T₃₆₀ or T₃₁₄ < 3%) are also shown at amplified scales in inserts (ordinate, 0%–12%; abscissa, 0%–3%).