The OsWRKY15-OsSUT3 Regulatory Module Enhances Rice Pollen Fertility by Mediating Sucrose Allocation to Anthers

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Sucrose transport and starch accumulation are vital for rice pollen maturation and fertility.
• The precise molecular regulation of these processes during rice pollen development is not fully understood.

Purpose of the Study:

• To elucidate the molecular mechanisms controlling sucrose transport and starch accumulation in rice pollen.
• To identify key genes and regulatory pathways involved in rice pollen development and fertility.

Main Methods:

• Map-based cloning and CRISPR/Cas9 mutagenesis to identify and characterize the sfp10 variant.
• Transcriptome analysis to identify regulatory factors.
• Yeast one-hybrid, EMSA, dual-luciferase reporter, and ChIP-seq assays to confirm gene interactions.

Main Results:

• The OsSUT3 gene encodes a sucrose transporter essential for sucrose uptake into pollen for starch synthesis.
• OsWRKY15, a transcription factor, directly binds to the OsSUT3 promoter and upregulates its expression.
• Disruption of OsWRKY15 or OsSUT3 impairs pollen fertility and seed setting, with combined mutations exacerbating the defects.

Conclusions:

• The OsWRKY15-OsSUT3 regulatory module is critical for sucrose transport and starch accumulation during late rice pollen development.
• This pathway is essential for ensuring rice pollen viability, fertility, and ultimately, grain production.