Functional characterization of transporter genes in rice node at single-cell resolution through multi-omics...

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Rice nodes are vital for distributing essential mineral nutrients like manganese (Mn).
• Understanding cell-type-specific transporters in rice nodes is crucial for Mn translocation and distribution.
• Molecular mechanisms of Mn transport in rice remain largely unknown.

Purpose of the Study:

• To identify cell types and transporter genes in rice nodes.
• To profile transporter gene expression across rice node cell types.
• To elucidate the role of specific transporters in Mn uptake and distribution.

Main Methods:

• Single-nucleus RNA sequencing (snRNA-seq) to characterize rice node cell types.
• Spatial ionomics to identify element deposition-linked transporters.
• Functional characterization of OsMTP7, including knockout and expression analysis.

Main Results:

• 11 distinct cell types and 1,144 transporter genes were profiled in rice nodes.
• Six candidate transporters for tissue-specific element deposition were identified.
• OsMTP7, a plasma membrane-localized Mn efflux transporter, was functionally characterized.
• OsMTP7 knockout impaired Mn uptake, translocation, and distribution, reducing biomass and yield.
• OsMTP7 knockout led to oxidative stress and reduced fertility in rice spikelets.

Conclusions:

• Precise cell types and enriched transporter genes in rice nodes were revealed.
• Candidate transporters for elemental deposition in rice nodes were identified.
• A novel Mn efflux transporter, OsMTP7, critically mediates Mn uptake, translocation, and distribution for improved rice growth and yield.