Genomic DNA-based absolute quantification of gene expression in Vitis

Area of Science:

• Molecular Biology
• Plant Science
• Genomics

Background:

• Gene expression studies commonly use relative quantification against a reference gene (RG).
• This method relies on assumptions of RG stability and equal reaction efficiencies, which are often inaccurate.
• Experimental determination of RG variability and reaction efficiencies is rarely performed.

Purpose of the Study:

• To develop a rapid and robust method for absolute gene expression quantification in Vitis.
• To assess the variability of a reference gene (VvUbi) using absolute quantification.
• To compare absolute quantification with traditional relative quantification methods.

Main Methods:

• Absolute quantification of gene expression using polymerase chain reaction (PCR) in Vitis.
• Construction of standard curves with varying concentrations of genomic DNA for absolute quantification.
• Validation of a reference gene (VvUbi) and quantification of a gene of interest (GOI) across different tissues and studies.

Main Results:

• Reference gene (VvUbi) expression varied significantly between studies and among samples.
• Absolute quantification consistently reduced coefficients of variation for genes of interest by over 50%.
• Differences in statistical significance were observed, with absolute quantification sometimes altering fundamental results.

Conclusions:

• Genomic DNA-based absolute quantification is a fast and efficient method for Vitis gene expression analysis.
• This methodology enhances accuracy and statistical power by eliminating errors from RG stability and efficiency assumptions.
• Absolute quantification provides a more reliable assessment of gene expression compared to relative methods.