Comparative Small RNA Profiling and Functional Exploration on Wheat With High- and Low-Cadmium Accumulation

Area of Science:

• Environmental Science
• Plant Biology
• Molecular Biology

Background:

• Cadmium (Cd) is a toxic metal pollutant prevalent in industrial settings and agricultural soils, posing risks to food safety through crops like wheat.
• Understanding plant responses to heavy metal stress at the molecular level is crucial for developing strategies to mitigate cadmium accumulation in food sources.
• MicroRNA (miRNA) research has emerged as a key area for investigating plant stress responses, offering insights into gene regulation.

Purpose of the Study:

• To investigate the microRNA profiles in contrasting wheat cultivars with high and low cadmium accumulation.
• To identify differentially expressed small RNAs and their target genes involved in cadmium stress response in wheat roots and leaves.
• To explore the potential of identified miRNAs as biomarkers for selecting low-cadmium-accumulating wheat.

Main Methods:

• Small RNA sequencing was employed to analyze microRNA expression profiles in high-cadmium-accumulating (Annong9267) and low-cadmium-accumulating (Qian 102032) wheat cultivars.
• Wheat cultivars were treated with cadmium (Cd) for 2 hours to observe immediate molecular responses in root and leaf tissues.
• Differential expression analysis and functional enrichment analysis of miRNA target genes were performed to identify key regulatory pathways.

Main Results:

• Specific microRNAs, including tae-miR9663-5p and tae-miR6201, were identified as potentially involved in cadmium accumulation mechanisms.
• Differentially expressed small RNAs related to cadmium accumulation were found in both wheat roots and leaves.
• Functional enrichment analysis revealed known and novel miRNAs and their target genes associated with cadmium stress in different plant tissues and cultivars.

Conclusions:

• The study identified key microRNAs and their target genes that play roles in cadmium accumulation in wheat.
• The identified differentially expressed miRNAs can serve as potential biomarkers for screening wheat varieties with low cadmium accumulation capacity.
• This research contributes to understanding molecular mechanisms of cadmium tolerance in plants and improving crop safety.