Interest is running high in the potential to protect crops from pests and diseases by triggering the plants' natural defence mechanisms with elicitors. Effective elicitors would help growers counter the impact of pests and pathogens developing resistance to chemical pesticides, products being withdrawn from the market or new pests and pathogens that may emerge. There is a need for more information about how elicitors work in the plant and the consequences of their use.
In AHDB project CP 105, PhD student Daniel De Vega Perez is investigating which elicitors can effectively induce resistance in tomato crops against Botrytis cinerea and identifying any drawback to the crop of this induced resistance, such as a reduction in growth or yield.
Experiments in the first two years of his studentship established that the plant hormone derivative methyl-jasmonate and the natural polysaccharide chitosan could elicit Botrytis resistance in tomato crops with no negative impact on growth or development.
While synthetic elicitor BABA (B-amino butyric acid) was shown in early experiments to induce long-lasting protection against Botrytis, it also caused a significant reduction in growth in both tomato varieties tested so was not investigated further.
Both methyl-jasmonate and chitosan have been shown to have a similar action, activating genes involved in the production of stress-signalling hormone jasmonic acid. This in turn switches on other genes that control plants' early-stage defences, such as the deposition of callose into cell walls to strengthen them and the production of natural "disinfectant" hydrogen peroxide in tissues around an infection site. You can find out more about this project on our website.
For details on all AHDB Horticulture activity, see horticulture.ahdb.org.uk