Engineered DNA polymerase improves PCR results for plastid DNA

Area of Science:

• Molecular Biology
• Plant Science
• Biotechnology

Background:

• Plant extracts contain secondary metabolites that inhibit PCR and sequencing.
• DNA polymerase inhibitor tolerance is crucial for successful amplification from difficult samples like herbarium specimens.

Purpose of the Study:

• To develop and evaluate a novel DNA polymerase engineered for enhanced tolerance to plant-derived PCR inhibitors.
• To optimize PCR parameters for improved DNA amplification from diverse plant species.

Main Methods:

• Directed evolution was used to engineer a DNA polymerase with improved inhibitor tolerance.
• PCR parameters were optimized for three plant species using the engineered enzyme.
• The engineered enzyme and optimized protocol were tested on an additional 31 species, compared to standard Taq polymerase.

Main Results:

• The engineered DNA polymerase achieved a 96% success rate for rbcL and 79% for matK amplification.
• Standard Taq polymerase yielded only 29% for rbcL and 21% for matK.
• High-quality sequence data was obtained for a significantly higher percentage of samples using the engineered enzyme.

Conclusions:

• The engineered DNA polymerase offers a substantial improvement for DNA amplification and sequencing from inhibitor-rich plant samples.
• This technology is particularly beneficial for analyzing DNA from silica-dried and herbarium plant materials.
• The developed system enhances the efficiency and success rate of molecular analyses in plant science.