Cell-Type-Specific and Variety-Specific Responses to Salt Stress in Wheat Root Revealed by Single-Cell...

Area of Science:

• Plant Biology
• Genomics
• Molecular Biology

Background:

• Soil salinization negatively impacts wheat yield and quality.
• Understanding root cell-type-specific responses to salt stress is crucial for improving crop tolerance.
• Previous research has not fully elucidated these specific mechanisms.

Purpose of the Study:

• To investigate cell-type-specific responses in wheat roots under salt stress.
• To identify molecular mechanisms underlying salt tolerance in different wheat varieties.
• To create the first single-cell atlas of salt-stressed wheat roots.

Main Methods:

• Single-nucleus RNA sequencing (snRNA-seq) of wheat root tips from salt-sensitive and salt-tolerant varieties.
• Profiling of over 188,000 high-quality root cells to identify 17 distinct cell types.
• Comparative gene expression analysis, pseudotime analysis, and subgenomic analysis.

Main Results:

• Root hair cells showed the strongest association with salt stress, with variety-specific transcriptional differences contributing to salt tolerance.
• Salt-sensitive varieties prioritized stress signaling and osmolyte accumulation, while salt-tolerant varieties focused on metabolic reprogramming and cellular repair.
• TaGSTU1-5B was identified as a key gene for salt tolerance, mediating ROS scavenging.
• Salt stress induced asymmetric homeolog expression in polyploid wheat roots.

Conclusions:

• This study provides the first single-cell atlas of salt-stressed wheat roots, revealing cell-type- and variety-specific responses.
• Identified TaGSTU1-5B as a potential target for enhancing wheat salt tolerance.
• Offers novel insights into the molecular basis of salt adaptation and tolerance in wheat, crucial for food security.