Ulvan long-term biostimulant effects on Arabidopsis thaliana seed treatment via medium supplementation

Abstract This study investigates the long-term effects of ulvan, a sulfated polysaccharide extracted from the green seaweed Ulva , on the growth and yield of Arabidopsis thaliana . While previous studies have demonstrated the short-term biostimulant effects of ulvan, well characterised ulvan long-term impact on plant development and seed yield remains unclear. The effects of a well-characterized crude ulvan extract on early germination, photosynthetic efficiency, root and shoot development, and final seed yield were determined. The results indicate that ulvan application at the time of sowing significantly enhances root elongation, shoot area, and photosynthetic activity, ultimately leading to a 43% increase in seed yield, suggesting a role in modulating metabolic pathways. Proteomic analysis further reveals significant upregulation of stress-related and growth-associated proteins, suggesting ulvan role in modulating metabolic pathways. Additionally, a comparative analysis of ulvan extracted two years apart demonstrates its biochemical consistency, reinforcing its potential for agricultural applications. These findings highlight ulvan promise as a sustainable biostimulant capable of reducing dependency on synthetic fertilizers while improving crop performance. Further research is needed to explore its efficacy across different crops and environmental conditions to optimize its integration into sustainable agricultural practices.