Responses of the green algal foliose lichen Platismatia glauca to increased nitrogen supply
Article first published online: 17 MAY 2006
Volume 171, Issue 2, pages 343–356, July 2006
How to Cite
Palmqvist, K. and Dahlman, L. (2006), Responses of the green algal foliose lichen Platismatia glauca to increased nitrogen supply. New Phytologist, 171: 343–356. doi: 10.1111/j.1469-8137.2006.01754.x
- Issue published online: 17 MAY 2006
- Article first published online: 17 MAY 2006
- Received: 16 January 2006 Accepted: 16 March 2006
- ammonium and nitrate;
- carbon (polyols);
- Trebouxia sp
- • Nitrogen (N) availability and light exposure were manipulated under field conditions to study responses to altered resource supply in the green algal lichen Platismatia glauca.
- • The lichen was fertilized with different concentrations and frequencies of ammonium, nitrate or glutamine under different light regimes for 2–3 months. Responses were followed from the intact thallus to the cellular level.
- • Despite significant differences in overall light exposure, light conditions were not significantly different among treatments when the lichens were wet and active. Ammonium was the preferred N source, followed by glutamine and then nitrate. Thallus N concentration as well as the chlorophyll a (Chl a) concentration increased 3–4-fold at the highest ammonium concentration, while the mycobiont ergosterol concentration remained unaltered. Growth was significantly enhanced by the enhanced N supply, with the increase in dry weight varying from 3 to 30%. Variation in Chl a concentration explained 31% of this variation, suggesting a causal link to the increased growth rate.
- • Platismatia glauca responded to increased N availability by increasing its growth rate and carbon assimilation capacity through increased investments in the photobiont cells. This suggests a tight regulation of resource investments and metabolic pathways between the symbionts of this lichen.