Dissecting the nutrient partitioning mechanism in rice grain using spatially resolved gene expression profiling

Area of Science:

• Plant Biology
• Molecular Biology
• Genomics

Background:

• Rice grain nutrient content varies across different tissues.
• Molecular mechanisms of nutrient partitioning in rice are not well understood.

Purpose of the Study:

• To investigate the molecular mechanisms of nutrient partitioning in rice grain tissues.
• To identify genes and regulatory elements controlling nutrient accumulation.

Main Methods:

• Optimized rapid laser capture microdissection (LCM) to isolate pericarp, aleurone, embryo, and endosperm.
• RNA-Seq analysis to identify differentially expressed genes (DEGs).
• Promoter sequence analysis to identify cis-elements.

Main Results:

• Identified 7760 DEGs across four distinct rice grain tissues.
• Discovered known and novel cis-elements regulating grain filling and seed development.
• Mapped spatial gene expression pathways for starch, protein, lipid, and iron accumulation.
• Revealed a gradient in seed storage protein accumulation and transcriptional regulation of mineral transporters, like iron.

Conclusions:

• Provides novel insights into rice grain nutrient partitioning mechanisms.
• Highlights the role of transcriptional control in mineral distribution.
• Offers a valuable interactive online resource for functional genomics research to enhance rice grain quality and seed development.