Plant protectors – how scientists save our crops

7th June 2022

Article by Josie Elliott, edited Ashely Baldwin.


As obvious as it sounds, plants can’t move. This means that when times get tough plants just have to stick it out and defend themselves as best as they can. Droughts, floods, and frosts can destroy plants. Weeds can steal light and nutrients. Insects and other pests eat away at leaves and stalks. Fungi, bacteria, and viruses can attack the plant and cause disease. These losses can have big economic effects, for example, last year floods and droughts cost the agricultural sector $21 billion and $37 billion respectively1.

However, plants aren’t helpless, and many have their own defences. Thorns on roses and stingers on nettles can put off an animal trying to eat these plants. Scientists have even found evidence that plants actually know when they’re being injured or eaten and can send distress signals to other leaves around the plant2. This is despite plants not actually having a nervous system like we do!

Even with their own defences, we want to protect plants from damage and loss because we need plants for clothes, medicine, fuel etc. What can we do to protect our plants? There are three main types of solutions:

Firstly, there’s pesticides, these are synthetically made chemicals that are applied to plants to kill unwanted insects, pathogens and weeds. Pesticides can be super useful because they kill a broad range of pests and disease-causing pathogens. However, that’s also part of their downside as they can contaminate areas and kill off animals and plants that aren’t pests at all.

What if we could harness biology and ecology to help us control pests instead of synthetic chemicals? Biocontrol uses living things to reduce the numbers of pests and pathogens. For example, Whiteflies can cause havoc around gardens and greenhouses, sucking up the sap of plants and leaving behind a sticky substance called honeydew which makes a perfect home for the growth of moulds. However, wasps can come to a farmer’s or gardener’s aid. The parasitic wasp Encarsia formosa lay their eggs inside Whitefly larvae, which causes the pest to die and become a host and food source for the baby wasps to feast upon as they grow. Gross, but useful.


White fly, Credit U.S. Department of Agriculture, 6.9.22

However, biocontrol can take a while to work and may mess with the food webs of the local area. What if instead we made plants better at protecting themselves? We can breed plants to become more resistant to drought, disease, or pests. However, this process can be slow and there can be trade-offs in productivity. This is where genetically modified (GM) plants can be helpful. Scientists can take bits of DNA that code for useful traits, like resistance or even production of vitamins, and put them into crop species. For example, researchers have been able to make GM potatoes that have been given a version of a gene from their wild relatives that makes them resistant to the late blight disease.

How would you design plant protection? Can you solve everything with GM? Become a plant protector with us at the SWBio teams’ Festival of Nature stall and let us know how you’d save our crops!

The SWBio team is a group of PhD researchers around the South West of the UK who work on a range of important biological questions, including how to help sick plants and better protect our crops into the future. We will be presenting a stall at the Festival of Nature Family Nature Party at Bristol Beacon on Sunday 12th June 10am - 4pm.

Who will be at Festival of Nature 2022 from SWBio?

Erika Kroll – Erika works on one of world most important crops – wheat. She dives into their genes and molecules to try and figure out how to protect them against pathogens.

Elliot Stanton – Elliot is at the frontline of research in how to protect the world against the antimicrobial resistance crisis. He harnesses computers and statistics to learn about the impact of antimicrobial drugs in agriculture.

Ellie Fletcher – Ellie is working to try and make sure we all have enough food to eat as the world’s population expands. She tinkers with plants not at the level of the leaf, or even the cell, instead she’s re-engineering the components inside of plant cells, and making them work better for us.

Ryan Biscocho – Ryan combines being both a biological and computer wizard to read the genetic code deeply enough so that he can try and understand how it evolved. Particularly how this code allowed agricultural domestication of the animals we rely on as food today.

Dunia Gonzales – Dunia is a bumblebee psychologist. She researchers how these plucky pioneers that pollinate our plants are able to navigate the world and create memories. You can also add drone pilot to the list as Dunia’s science includes using drones to take aerial footage of the bees habitats.


Activity

Would you be a good plant? This game from University of Bristol researcher Ashley Pridgeon (@AJPridgeon) gives you an insight into their work on microscopic plant pores, called stomata.
whatstomata.com

Learn more

This blog post was inspired by: https://www.bspp.org.uk/wp-content/uploads/2019/02/BSPP_SOP_Intro_A3.pdf

Learn more about pesticides: https://www.bspp.org.uk/wp-content/uploads/2019/02/BSPP_SOP_Pesticides_A4.pdf

Learn more about biocontrol: https://www.bspp.org.uk/wp-content/uploads/2019/02/BSPP_SOP_BioCon_A4.pdf

Lean more about GM plants: https://www.bspp.org.uk/wp-content/uploads/2019/02/BSPP_SOP_GM_A4.pdf

References

1 – Food and Agriculture Organisation of the United Nations, 2021 https://www.fao.org/resources/digital-reports/disasters-in-agriculture/en/

2 – Tech times, 14 September 2018 https://www.techtimes.com/articles/234321/20180914/look-plants-send-out-distress-signals-in-response-to-threats-such-as-being-eaten.html