Gender-specific physiological plasticity and photosynthetic adaptation in Populus cathayana and Salix babylonica under strontium stress: Implications for phytoremediation and environmental resilience

Abstract

This study investigates the gender-specific response mechanisms of Populus cathayana and Salix babylonica to strontium (Sr) stress using controlled pot experiments. The research focused on Sr enrichment traits and physiological reactions under varying Sr²⁺ concentrations. Results indicated that the translocation coefficient was higher in S. babylonica than in P. cathayana, particularly in females. The value in female S. babylonica (3.026) was 1.36 times that in P. cathayana. Gender-based differences in translocation were significant in both species. Under high Sr²⁺ stress (100 mg·L⁻¹), leaf area was inhibited in both species, whereas the height of P. cathayana was promoted, with males growing 1.22 times taller than females. Low Sr²⁺ treatment (10 mg·L⁻¹) enhanced stomatal conductance (Gs), transpiration rate (E), and net photosynthetic rate (A) in females of both species. Antioxidant enzyme activities in male P. cathayana and female S. babylonica showed an initial increase followed by a decrease with rising Sr²⁺ levels. The PLS-PM model further elucidated the relationships among biological enrichment, osmotic regulators, soil enzyme activities, and photosynthetic parameters. These findings provide a theoretical basis for breeding Sr-resistant woody plants and contribute to understanding the interaction between plant gender and environmental stress.

Graphical abstract