Adaptation strategies of forage soybeans cultivated on acidic soils under cool climate
Muhammad Nadeem*, Thu Huong Pham, Ashley Nieuwenhuis, Waqas Ali, Muhammad Zaeem, Waqar Ashiq, Syed Shah Mohioudin Gillania, Charles Manful, Oludoyin Adeseun Adigun, Lakshman Galagedara, Mumtaz Cheema* and RaymondThomas*.
Plant Science, Volume 283, June 2019, Pages 278-289 https://doi.org/10.1016/j.plantsci.2019.03.014
• Forage soybean produced less biomass at neutral pH compared to acidic pH.
• Soybean plants produced similar forage quality at different pH in podzolic soils.
• Four major lipid species; PC, PE, PA and AGIcSiE were observed in soybean roots.
• Forage soybean roots remodeled membrane lipid profile under different pH in podzolic soils.
• Soybean roots tend to bring membrane lipid profile close to neutral pH when grown in acidic soils.
Boreal soils tend to be podzols characterized by acidic pH, which can further limit forage crop growth and production. It is unclear, how forage soybeans adopt to produce forage with high nutritional quality when cultivated on podzols in boreal climate. To answer this question, we cultivated forage soybeans on agricultural podzols at 3 farm sites with varied soil pH (6.8, 6.0 or 5.1), and assessed the root membrane lipidome remodeling response to such climatic conditions. Contrary to our expectations, significantly lower biomass was observed at pH 6.8 compared to 6.0 and 5.1. However, surprisingly the plants produced similar forage quality at 6.8 and 5.1 pH. Three major lipid classes including phospholipids, glycolipids and phytosterols were observed in roots irrespective of soil pH. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA), and acylated glucosyl betasitosterol ester (AGlcSiE) accounted for 95% of the root lipidome, and expressed significant changes in response to cultivation across the three soil pH levels. These lipids were also observed to have strong correlations with forage production, and forage quality. Therefore, soybean genotypes with higher abilities to remodel PC, PE, PA, and AGlcSiE could be better suited for producing higher quality forage in acid podzolic soils characteristics of boreal ecosystems.