Tuning growth/defense trade-offs in plants by dissecting their molecular basis: grow and defend?

Summary

Because plants are sessile, their survival depends on rapidly adapting to unfavorable conditions. They need to defend themselves against pathogens and herbivores, and at the same time grow large enough to compete with neighboring plants for light and nutrients. However, plant defense reduces growth and vice versa through molecular and hormonal cross-talk. Uncoupling this growth/defense trade-off will increase crop yield by improving plant defense and growth.

When plants are attacked by insects or pathogens, they produce the hormone Jasmonic acid (JA). Once produced, JA triggers a defense response in plants but also inhibits their growth. Preliminary data indicate that in Arabidopsis, the transcriptional regulator JACKDAW (JKD) mediates JA response by modulating the expression of JA-responsive genes. Mutation of JKD increased resistance to the pathogen Botrytis cinerea. Interestingly, the enhanced resistance does not appear to inhibit growth: the mutant even has larger leaves. While JKD’s role in root development is well-established, no role in defense or growth of above-ground organs has yet been attributed.

I will study the role of JKD in plant defense through identification of target genes in roots and leaves. In addition, I will evaluate whether growth of the mutant is in any way compromised. This research will initially focus on the model species Arabidopsis, but crop species could also benefit from JKD mutations because JKD-type proteins are conserved within the plant kingdom. To test this, I will investigate the effects of JKD mutations in tomato. I will use the novel, revolutionary CRISPR/Cas9 technology to create tomato jkd mutants. My expertise on plant development and transcriptional regulation makes me the right person for this project.

I will unravel the regulatory mechanisms that connect plant defense and growth. My findings will be used to improve crop yield by enhancing resistance while maintaining or promoting plant growth.

Details

Project number

15891

Main applicant

Dr. A. Horstman

Affiliated with

Wageningen University & Research, Wageningen Plant Research, Ontwikkelingsbiologie

Duration

01/05/2018 to 31/08/2021