GroundCoverTM writer Catherine Norwood with a vial of infected leaf.
1. Clip a one-centimetre piece of the potentially infected plant matter and add it to a vial containing a buffer that helps to extract the plant pathogen’s DNA. When you shake the vial, which also contains a ball bearing, this breaks down the plant matter and releases the DNA.
Researchers from Victoria’s Centre for Agribioscience (AgriBio) demonstrated the simplicity of loop-mediated isothermal amplification (LAMP) technology at the recent Plant Biosecurity Cooperative Research Centre (PBCRC) Science Exchange.
LAMP tests have been used widely overseas and Australian researchers are developing tests to identify viral, bacterial and fungal infections affecting Australian crops.
2. Take a small sample of the mix and add it to another vial containing purified water to dilute it.
Once the DNA of a plant pathogen has been isolated and the appropriate LAMP assays have been developed, the LAMP process can be done quickly and effectively in the lab or in the field. It takes just a few minutes to prepare the sample and then run the test on a highly portable OptiGene machine, producing a diagnosis in about 30 minutes.
3. Take an even smaller sampler of the diluted liquid and add it to the testing vials that contain the LAMP assay to amplify the DNA.
4. Put the testing vials in the OptiGene machine, which holds the temperature at 65ºC for 30 minutes. The temperature is key to the optimal performance of the enzyme in the LAMP assay. The machine then produces a print-out that identifies whether the target virus is present.
Tests for bacterial and fungal pathogens with DNA genomes are simpler to develop than those for viruses with RNA genomes, as RNA is less stable than DNA and more difficult to extract. Most LAMP tests developed or adopted for use in Australia so far target horticultural bacterial pathogens. The test developed by AgriBio’s Dr Linda Zheng for barley yellow dwarf virus is Australia’s first LAMP test for a plant virus.
Smart surveillance on the move
Blackleg in pink