New DNA analysis method reveals plant immunity
22 Dec 2016 by Evoluted New Media
A new, improved method to capture longer fragments of DNA will allow researchers to understand more about the genes that provide plants with immunity to disease.
A new, improved method to capture longer fragments of DNA will allow researchers to understand more about the genes that provide plants with immunity to disease.
Currently, Resistance gene enrichment sequencing (RenSeq) is used to sequence resistance (R) genes that confer disease resistance in plants. This new method allows food scientists to distinguish R genes that encode proteins that provide disease resistance in plants.Dr Matt Clark, from the Earlham Institute and lead author of the study, said: “In this study, by optimising multiple steps in the library construction, we can identify the protein-coding sequences and the neighbouring regulatory regions; indeed in many cases, we can reconstruct the entire DNA region even if it contains many similar genes which normally are too hard to tell apart. This means we can identify the exact gene that confers resistance to a certain infection, and used in breeding programmes.”
Work by scientists from the EI, The Sainsbury Laboratory (SL) and the James Hutton Institute (JHI), has enabled up to 7000 DA bases to be analysed. Each plant carried hundreds of potential R gene sequences, identified by the presence of specific sequence motifs – short, recurring DNA patterns believe to have a biological function.
When a pathogen invades a plant, it uses effector molecules to weaken it. The R gene proteins recognise these molecules and signal the plant to kill cells around the infection site to prevent it spreading. Combining PacBio, a programme able to read longer sequences of DNA, with Renseq provides information on R genes as well as promoters and terminators – the regulatory DNA regions that signal when to start and stop making a protein.Dr Ingo Hein, from the JHI and co-author, said: "The ability to capture and sequence long genomic DNA fragments that contain full-length R genes enables the rapid identification of novel, functional resistance genes from wild species. These genes, if introgressed into new cultivars via breeding or alternative routes, could significantly reduce the dependency on pesticides for crop production."
The paper is published in BioTechniques.