OsLPR5 Encoding Ferroxidase Positively Regulates the Tolerance to Salt Stress in Rice.

Area of Science:

• Plant Biology
• Molecular Biology
• Abiotic Stress Research

Background:

• Salinity significantly impacts rice yield.
• Low phosphate roots (LPRs) are involved in phosphate deficiency but their role in salt tolerance is unclear.
• Ferroxidase activity is a known function of LPRs.

Purpose of the Study:

• To investigate the function of LPRs, specifically OsLPR5, in rice salt stress response and tolerance.
• To determine the molecular mechanisms underlying OsLPR5's role in salinity tolerance.

Main Methods:

• Gene expression analysis under NaCl stress.
• Phenotypic analysis of wild-type, OsLPR5 overexpressing lines, and lpr5 mutants under salt stress.
• Measurement of ferroxidase activity, chlorophyll content, MDA levels, osmotic adjustment substances, ROS-scavenging enzyme activities, and ion content (Na+, K+).

Main Results:

• OsLPR5 expression is induced by NaCl stress.
• Overexpression of OsLPR5 enhances salt tolerance, indicated by increased ferroxidase activity, higher chlorophyll, lower MDA, and improved osmotic adjustment and ROS scavenging.
• The lpr5 mutant exhibits reduced ferroxidase activity and increased sensitivity to salt stress, with higher Na+ accumulation and Na+/K+ ratios.

Conclusions:

• OsLPR5 positively regulates salt stress tolerance in rice.
• OsLPR5's ferroxidase activity is crucial for its function in salt tolerance.
• This study reveals a novel link between ferroxidase activity and plant salt tolerance in rice.