The Impact of OsERF34 on Rice Grain-Processing Traits and Appearance Quality

Area of Science:

• Plant Molecular Biology
• Crop Quality Improvement
• Agricultural Science

Background:

• Head rice rate is crucial for rice quality but is often limited.
• ETHYLENE RESPONSIVE FACTOR34 (OsERF34), an APETALA2 (AP2/ERF) transcription factor, is implicated in plant development.
• Understanding OsERF34's role is key to enhancing rice processing quality.

Purpose of the Study:

• To characterize the function of OsERF34 in rice grain morphology and processing quality.
• To investigate the effects of OsERF34 knockout and overexpression on rice physicochemical properties.

Main Methods:

• CRISPR/Cas9-mediated knockout (Oserf34) and overexpression (OsERF34-OE) in japonica rice (ZH11).
• Analysis of grain morphology, chalkiness, starch properties, and milling resistance.
• Evaluation of head rice rate and processing breakage.

Main Results:

• Oserf34 mutants showed increased chalkiness, disordered starch granules, reduced amylose, and diminished milling resistance, leading to higher breakage and lower head rice rates.
• Both mutants and OE lines exhibited grain narrowing, but OE lines displayed enhanced mechanical robustness.
• OsERF34-OE lines achieved significantly higher head rice rates (6.5-7.1%) and improved milling quality.

Conclusions:

• OsERF34 acts as a dual-function regulator, influencing grain appearance and processing quality.
• Overexpression of OsERF34 enhances grain mechanical properties and improves processing efficiency.
• OsERF34 is a promising target for precision breeding to improve rice quality and processing.