Physiological and Transcriptomic Analysis of Bread Wheat MicroRNAs in Response to Zinc Availability

Area of Science:

• Plant Biology
• Molecular Biology
• Agricultural Science

Background:

• Zinc (Zn) is vital for plant growth, but soil deficiency or excess impairs crop yields.
• MicroRNAs (miRNAs) are known regulators of abiotic stress responses, yet their role in wheat zinc homeostasis is unexplored.

Purpose of the Study:

• To investigate miRNA expression profiles in bread wheat (Triticum aestivum L.) roots under varying zinc (Zn) supply.
• To identify key miRNAs and their target genes involved in Zn homeostasis and stress response in wheat.

Main Methods:

• High-throughput sequencing of miRNA expression in wheat roots under different Zn conditions.
• Phenotypic, physiological, and bioinformatics analyses including target gene prediction and pathway enrichment.

Main Results:

• Identified 798 miRNAs (70 known, 728 novel), with 132 differentially expressed.
• Key miRNAs (e.g., miR397-5p, miR398) showed differential regulation under low, high, and excess Zn.
• Target genes were enriched in processes like zinc transport, detoxification, glutathione metabolism, and ABC transporters.

Conclusions:

• Identified specific miRNAs crucial for managing both Zn deficiency and toxicity in wheat.
• Revealed distinct regulatory pathways for target genes under different Zn availabilities.
• These findings offer valuable miRNA candidates for breeding wheat with enhanced zinc utilization efficiency.