Leaf anatomy mediates coordination of leaf hydraulic conductance and mesophyll conductance to CO in Oryza.

Leaf hydraulic conductance (K ) and mesophyll conductance (g ) both represent major constraints to photosynthetic rate (A), and previous studies have suggested that K and g is correlated in leaves. However, there is scarce empirical information about their correlation. In this study, K , leaf hydraulic conductance inside xylem (K ), leaf hydraulic conductance outside xylem (K ), A, stomatal conductance (g ), g , and anatomical and structural leaf traits in 11 Oryza genotypes were investigated to elucidate the correlation of H O and CO diffusion inside leaves. All of the leaf functional and anatomical traits varied significantly among genotypes. K was not correlated with the maximum theoretical stomatal conductance calculated from stomatal dimensions (g ), and neither g nor g were correlated with K . Moreover, K was linearly correlated with g and both were closely related to mesophyll structural traits. These results suggest that K and g are related to leaf anatomical and structural features, which may explain the mechanism for correlation between g and K .