Effect of Si on P-Containing Compounds in Pi-Sufficient and Pi-Deprived Wheat

Addition of fertilizers has become a common practice to combat phosphate scarcity in agriculture. Food requirements of increasing human population need to be addressed, but by using less resources and by avoiding nutrient losses. There is consequently an increasing interest in the amelioration of the utilization of phosphate, and in this regard, biostimulants remain a promising strategy. Biostimulant properties of silicon have started to be disclosed during the last years, but no effects have been described to date in the plant phosphorus-containing metabolites. Here, we treated wheat plants with and without phosphate and silicon throughout 30 days and we performed different analyses including phosphorus concentration measurements, gene expression, and UPLC-MS/MS analyses, to characterize the phosphate status of plants and their phospho-metabolome profiles. Interestingly, we found that plants grown with no addition of external phosphate and supplemented with silicon showed higher levels of phosphate after 30 days. Metabolomic approaches allowed us to identify that this phosphate was recycled from phosphorus-containing metabolites in shoots (sugar phosphates, phospholipids, and nucleotides). We demonstrate that silicon may effectively promote phosphate recycling from phospho-metabolites in phosphate-deprived wheat.

Automated summary

The study showed that under conditions of external phosphate deprivation, the addition of silicon can promote wheat plants to recycle phosphate from phospho-metabolites, leading to increased phosphate absorption and utilization efficiency.