Environmental plant physiology

• Limitations in photosynthesis

• Light• Carbon dioxide

Limitations

• Optimal PS requires• Rubisco acitivity• Regeneration of RuBP• Metabolism of Triose phosphates

Sun and shade leavesSun leaf Shade leaf

• Sun leaves thicker, palisade cells elongated, more rubisco, more xanthophyll cycle components

• Shade leaves thinner, more total chlorophyll per reaction center, more chl b,

Sun and shade plants

Light levels

Carbon Dioxide Levels

C3 vs C4

CAM plants

C3 and C4 plants

Comparison of photosynthetic characteristics

Isotope discrimination