Morphological and Transcriptomic Analyses Provide New Insights into Linseed (Linum usitatissimum L.) Seedling Roots...

Area of Science:

• Plant Biology
• Agronomy
• Genetics

Background:

• Nitrogen (N) is a critical macronutrient for plant growth, but its inefficient use increases crop costs and environmental pollution.
• Developing N-efficient crops requires understanding plant adaptation mechanisms under N stress.

Purpose of the Study:

• To assess phenotypic and gene expression responses of contrasting linseed genotypes to N stress.
• To identify candidate genes involved in N stress adaptation in linseed.

Main Methods:

• Phenotypic analysis of twelve traits in two linseed accessions under N stress.
• RNA sequencing (RNA-Seq) for root gene expression profiling.
• Differential gene expression analysis to identify DEGs.

Main Results:

• Nine out of twelve phenotypic traits were significantly affected by N stress, including root and shoot biomass and N content.
• An N-efficient (NE) genotype consistently outperformed an N-inefficient (NI) genotype under both N stress and normal conditions.
• Transcriptome analysis revealed 1034 differentially expressed genes (DEGs), with notable representation from ERF, MYB, NAC, and WRKY transcription factor families.

Conclusions:

• Linseed genotypes exhibit distinct responses to N stress at both phenotypic and transcriptomic levels.
• Candidate genes related to N absorption, transport, root development, and antioxidant activity are implicated in N stress adaptation.
• The identified genes provide a foundation for breeding N-efficient linseed cultivars with enhanced root systems.