Reference gene identification for gene expression analysis in rice under different metal stress

Area of Science:

• Plant Molecular Biology
• Environmental Stress Physiology
• Biotechnology

Background:

• Accurate quantification of gene expression changes is vital for understanding plant responses to environmental stimuli.
• Real-time quantitative polymerase chain reaction (RT-qPCR) is a widely used method for gene expression analysis.
• Selection of appropriate internal reference genes is critical for normalizing RT-qPCR data and ensuring reliable results.

Purpose of the Study:

• To identify and validate stable reference genes for gene expression analysis in rice seedlings exposed to various heavy metal stresses.
• To compare the expression stability of candidate reference genes with a commonly used housekeeping gene (OsUBQ5).
• To provide reliable reference genes for accurate gene expression studies under specific heavy metal stress conditions in rice.

Main Methods:

• Identification of 10 candidate reference genes with stable expression from public RNA-Seq data.
• Inclusion of the housekeeping gene OsUBQ5 for comparative analysis.
• Determination of expression stability using two independent software tools: NormFinder and geNorm.

Main Results:

• The identified candidate reference genes exhibited higher expression stability compared to OsUBQ5 under heavy metal stress.
• Genes LOC_Os03g16690 (OsOBP) and LOC_Os01g56580 (OsCK1a.3) were found to be the most stably expressed across tested conditions.
• Expression stability varied depending on the specific heavy metal stress applied.

Conclusions:

• Specific reference genes are recommended for specific heavy metal stress conditions in rice, rather than a single universal reference gene.
• The identified reference genes (OsOBP and OsCK1a.3) are valuable tools for accurate gene expression normalization in rice under heavy metal stress.
• This research enhances the reliability of RT-qPCR-based gene expression studies in plants facing heavy metal challenges.