Legume-based selenium bioavailability for crop and human nutrition: A global meta-analysis

Area of Science:

• Agricultural Science
• Plant Physiology
• Nutritional Science

Background:

• Selenium (Se) is vital for plant growth and human nutrition, but its narrow safety margin poses risks in legume-based food systems.
• Understanding precise Se application is essential for sustainable agriculture and biofortification of legumes.

Purpose of the Study:

• To conduct a meta-analysis and machine learning assessment of Se effects on legume growth, physiology, and biofortification.
• To determine optimal Se application rates and factors influencing its impact on legumes.

Main Methods:

• Meta-analysis of 1644 pair-wise observations (2009-2024).
• Analysis using machine learning models: Random Forest (RF), XGBoost, and Support Vector Machines (SVM).
• Evaluation of Se fertilizer type, concentration, exposure duration, application method, and growth medium.

Main Results:

• Se application ≤2.5 mg/kg^-1 enhanced shoot dry weight, yield, chlorophyll, and antioxidant enzymes (SOD, POD, CAT, APX), while reducing oxidative stress (H₂O₂).
• Higher Se levels (>2.5 mg/kg^-1) negatively impacted yield, germination, antioxidant defenses, and increased oxidative damage.
• Se accumulation in grains varied by exposure medium, with hydroponics showing the highest accumulation, followed by soil.

Conclusions:

• Precise Se application at ≤2.5 mg/kg^-1 optimizes legume performance and nutritional quality.
• Machine learning identified Se concentration, fertilizer type, and exposure matrix as key factors influencing Se impact.
• This research supports sustainable legume production and biofortification strategies globally.