PHOTOSYNTHETICA

Photosynthetica 2022, 60(2):240-250 | DOI: 10.32615/ps.2022.012

Leaf structure and photosynthesis in Populus alba under naturally fluctuating environments

X.Y. LIN^{1, 2, 3}, X.X. WANG³, Q.Y. ZENG^{1, 2, 3}, Q. YANG^{3, 4}

¹ State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China

² University of Chinese Academy of Sciences, 100049 Beijing, China

³ State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, 100091 Beijing, China

⁴ State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, 311300 Zhejiang, China

The ability to modulate photosynthesis is essential for plants to adapt to fluctuating growing conditions. Populus species show high tolerance to various and highly variable environments. To understand their response strategies against fluctuating environments, this study investigated the morphological and physiological differences of white poplar (Populus alba) leaves when grown in a phytotron, glasshouse, and field. Our results show that the palisade cells were elongated in the field, which would enhance intercellular CO₂ exchange. Photosynthetic capacity was the highest in the field leaves, as shown by higher electron transport rates (1.8 to 6.5 times) and carbon assimilation rates (2.7 to 4.2 times). The decrease of PSI acceptor-side limitation and increase of PSI donor-side limitation suggests changes in PSI redox status may contribute to photoprotection. This plasticity of white poplar allows adjusting its structure and photosynthesis under fluctuating conditions, which may partly enable its outstanding tolerance against environmental changes.

Additional key words: fluctuating conditions; photoinhibition; photosynthesis; plasticity; Populus alba.

Received: October 18, 2021; Revised: February 23, 2022; Accepted: February 23, 2022; Prepublished online: March 28, 2022; Published: May 2, 2022  Show citation