Transcriptome Analysis of Two Near-Isogenic Lines with Different NUE under Normal Nitrogen Conditions in Wheat

Area of Science:

• Plant Molecular Biology
• Agricultural Science
• Genetics

Background:

• Nitrogen (N) is crucial for crop yield, but nitrogen use efficiency (NUE) declines with increased N application.
• Molecular mechanisms underlying genotypic differences in wheat NUE are not well understood.

Purpose of the Study:

• To investigate the molecular mechanisms of genotypic differences in wheat nitrogen use efficiency (NUE).
• To compare the transcriptome profiles of high-NUE and low-NUE wheat near-isogenic lines (NILs) under normal nitrogen conditions.

Main Methods:

• RNA-Sequencing (RNA-Seq) was employed to analyze flag leaf transcriptomes at anthesis in two wheat NILs (1Y: high-NUE, 1W: low-NUE).
• Differential gene expression analysis was performed under normal nitrogen conditions (300 kg N ha^-1).

Main Results:

• 7023 differentially expressed genes (DEGs) were identified between the high-NUE (1Y) and low-NUE (1W) lines.
• Genes in the glutamine synthetase (GS) and glutamate synthase (GOGAT) families were upregulated in the high-NUE line.
• Enhanced carbon metabolism and key transcription factor families (ERF, WRKY, NAC, MYB) were implicated in NUE differences.

Conclusions:

• Transcriptional regulatory mechanisms differ between wheat genotypes with varying NUE.
• Upregulation of GS/GOGAT and enhanced carbon metabolism in high-NUE wheat contribute to efficient nitrogen utilization.
• Identified candidate genes offer insights into genotypic variations in wheat NUE.