Fulvic acid application increases rice seedlings performance under low phosphorus stress

Area of Science:

• Agricultural Science
• Plant Physiology
• Soil Science

Background:

• Low phosphorus fertilizer utilization efficiency is a major agricultural challenge.
• Fulvic acid is known to enhance plant growth and interact with phosphate fertilizers.
• The precise mechanisms by which fulvic acid alleviates phosphorus deficiency remain unclear.

Purpose of the Study:

• To investigate the impact of varying fulvic acid concentrations on rice growth under low phosphorus stress.
• To elucidate the physiological and molecular mechanisms underlying fulvic acid's effects on rice phosphorus uptake and stress tolerance.

Main Methods:

• Rice plants were grown in a hydroponic system under varying concentrations of fulvic acid (0, 40, 60, 80, 120 mg/L) and low phosphorus stress.
• Evaluated rice growth phenotypes, biomass, root morphology, and phosphorus uptake.
• Assessed changes in the rhizosphere environment, including organic acid concentration and gene expression of key transporters and enzymes.

Main Results:

• Optimal fulvic acid concentrations (40 and 60 mg/L) significantly increased rice biomass and stimulated root development.
• Fulvic acid treatments up-regulated phosphate transporter genes, enhancing phosphorus absorption and accumulation.
• Elevated organic acid concentration in roots and up-regulated plasma membrane H+-ATPase genes were observed, facilitating organic acid secretion and alleviating phosphorus stress.

Conclusions:

• Exogenous fulvic acid application is concentration-dependent in its effect on rice physiological indicators under low phosphorus stress.
• Fulvic acid enhances rice performance and reduces reliance on phosphorus fertilizer by improving phosphorus uptake and root development.
• Fulvic acid represents a promising eco-friendly tool for mitigating low phosphorus stress in rice cultivation.