Light quality shapes mesophyll conductance in cucumber leaves in association with coordinated anatomical changes.

Blue-enriched light spectra (25B, 75B, 100B) increase mesophyll conductance and photosynthetic rate in cucumber leaves compared to red light, with 75B showing the highest performance.

• Why it matters: Understanding how light quality influences leaf anatomy and internal CO2 diffusion is crucial for optimizing photosynthesis and crop productivity in controlled environments.
• What they did: The study examined how different red and blue light ratios affected leaf anatomical traits, mesophyll conductance, and photosynthesis in cucumber, using measurements and modeled diffusion resistance.
• The result: Findings reveal that blue-enriched spectra promote anatomical features associated with higher mesophyll conductance, with cell wall and chloroplast stromal resistances being key factors, and mesophyll limitation remaining dominant across treatments.