Abstract
BACKGROUND: Biostimulants positively impact plant growth, yield, and chemical composition while enhancing tolerance to biotic and abiotic stress. Phosphite (Phi), a phosphate analog, has been proposed as a biostimulant due to its advantages over traditional phosphate fertilizers and herbicides. METHODS: This study evaluated the effects of Phi on sugarcane seedlings (CP 72-2086) under conventional (non-stress) and osmotic stress conditions during in vitro multiplication. Seedlings were treated with Phi at 0.1, 0.3, and 0.5 mM (derived from H(3)PO(3)) for 30 days, followed by 7 days of osmotic stress induced with 10% polyethylene glycol 6000 (PEG). RESULTS: Phi significantly increased leaf length, width, and number, as well as shoot count. Additionally, it enhanced foliar concentrations of chlorophylls a and b, sugars, and amino acids under both conventional and osmotic stress conditions. In conclusion, Phi serves as an effective inorganic biostimulant for sugarcane (CP 72-2086) during in vitro multiplication, stimulating seedling growth and modulating essential biomolecule concentrations.