GALAXY is our proprietary high-throughput screening platform at Moa: the first step in how we find new herbicides that will help farmers protect their harvests from herbicide-resistant weeds. With GALAXY, we have been able to screen 750,000 compounds and identify over 70 new mode of action areas in the last three years: a massive industry breakthrough in speed, reliability and accuracy.
As one of the scientists working in the GALAXY team, I like to think I may be the first person ever to see the next big herbicide that will help to protect the world’s crops in a few years’ time.
But why me?
There are many parts to our process, but the team I work in is involved right at the start. We treat special miniaturised whole plants (grown in our own labs) with thousands of different synthetic and naturally occurring compounds, and then record images of them. We compare how the miniaturised plants treated with our compounds appear in the images – a response we call a phenotype – to images of plants treated with commercial herbicides. If they look different, we know there’s a good chance we’ve found a compound that acts in a novel way and it will move on to our other proprietary platforms to be investigated further.
Our process is based on recognising known modes of action in images we take of the plants. To obtain these crucial images of our test plants, we use a technique called high-content fluorescence microscopy. When we shine red light on chlorophyll, it absorbs light then re-emits it, fluorescing at a different wavelength. We can filter out the wavelengths of light that we shone onto the plant, and only image the wavelengths that chlorophyll emits. Since chlorophyll is naturally fluorescent, we don’t need to genetically modify our plants or use dyes to see chlorophyll and therefore the chloroplasts. However, we still have the option of using dyes and reporter lines to study other biological processes, should we wish to.
How accurate is this method? Our team has been tested in our capability to decipher mode of action compounds blindly. In these tests, we were given compounds with known mode of actions to screen in GALAXY, without being told what they are or how they work. Using only our phenotypic assay, we scored about 96% accuracy in those blinded tests, and I would like to think we have since improved as we have become more and more experienced with this process!