C3 photosynthetic activity in ephemeral leaflets of the constitutive CAM species Opuntia ficus-indica.

Ephemeral leaflets of Opuntia ficus-indica perform C3 photosynthesis, contributing about 20% of carbon to early cladode growth during water pulses.

• Why it matters: Understanding how different plant organs contribute to carbon fixation is crucial for revealing adaptive strategies in arid environments, especially in CAM species.
• What they did: Researchers used gas exchange, stomatal analysis, acidity assays, isotope discrimination, and pulse-labeling on 50+ leaflets to determine their photosynthetic pathway and contribution to carbon economy.
• The result: Findings show leaflets operate via C3 photosynthesis, supplying roughly 0.12 g C per cladode daily, and their removal significantly hampers cladode growth, highlighting their role in rapid biomass accumulation.