Interaction between sulfur and selenium in agronomic biofortification of cowpea plants under field conditions

• Published in: Plant and soil 2023-05, Vol.486 (1-2), p.69-85
• Main Authors: Silva, Vinícius Martins, Wilson, Lolita, Young, Scott D., Broadley, Martin R., White, Philip J., Reis, André Rodrigues dos
• Format: Article
• Language: English
• Subjects: Agriculture; Amino acids; Analysis; Assimilation; biofortification; Biomedical and Life Sciences; Biosynthesis; Cowpea; Cowpeas; Design of experiments; Ecology; Experimental design; Growth; Leaves; Life Sciences; Metabolic pathways; Metabolism; Plant growth; Plant Physiology; Plant Sciences; Plant tissues; Proteins; Research Article; Seeds; selenates; Selenium; soil; Soil Science & Conservation; Storage proteins; Sucrose; Sugar; sulfates; Sulfur; Vigna unguiculata
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-022-05480-8

Aims Selenium (Se) as selenate shares similarities with sulfate in transport and assimilation by plants. Uptake and assimilation of Se might be affected by S and vice-versa, which could affect Se and S concentration in plant tissues, and metabolic pathways such as biosynthesis of sugars, amino acids, and storage proteins. This study aimed to evaluate Se and S combination on cowpea plants under field conditions. Methods The experimental design was a 4 × 4 interaction between four rates of Se (0, 10, 25, and 50 g ha − 1 ) and four rates of S (0, 15, 30, and 60 kg ha − 1 ) in two consecutive years of cowpea cultivation. Concentrations of Se, S, total sugars, sucrose, total free amino acids, and storage proteins in plant tissue were measured. Results The Se x S interaction did not affect cowpea yield or growth. Antagonistic effects of S on Se concentrations in leaves and seeds were observed mainly for the second crop season. Selenium did not decrease S concentrations in leaves and seeds of cowpea plants. The combination of 25 g Se ha − 1 and 30 kg S ha − 1 provided the greater concentrations of total sugars. Interaction between Se and S was associated with greater sucrose, amino acids, and storage proteins concentrations in cowpea seeds. Conclusions The Se and S interaction did not impair plant growth but application of S decreased Se content in cowpea. Further studies are needed to better understand the physiological roles of Se and S combination in producing primary metabolic compounds.