Mechanisms of plant defence priming using seed treatments

Lead Research Organisation: Rothamsted Research
Department Name: Unlisted

Abstract

This project will establish the science underpinning our recent discovery that soaking seeds of plants in plant defence hormones confers long-lasting pest resistance in plants grown from these seeds. It will investigate the fundamental mechanisms behind priming of defence against pests and diseases by seed treatments with jasmonic acid (JA) and the nonprotein amino acid, beta-aminobutyric acid (BABA). The primary objectives are:
1. To determine the extent to which JA and BABA seed treatments directly stimulate defence even without any biotic attack, and the extent to which they act via priming. This objective will be achieved by investigating (i) transcriptional profiles, and (ii) profiles of volatile emissions, in control and seed-treated plants before and after pest attack.

2. To examine the contribution of chromatin remodelling and DNA methylation to the priming of defence-related genes in seed-treated plants.

3. To investigate the impacts of seed treatments with JA and BABA on (i) direct defences against herbivores, (ii) indirect defences against herbivores, and (iii) pathogen resistance.

4. To test the hypothesis that JA and BABA act independently, providing additive (or even synergistic) effects on defence when used as a combined seed treatment.

The project will generate data relating to plant responses to JA and BABA seed treatments at three levels: gene expression, volatile emission and susceptibility to insect attack. Molecular and biochemical changes will be compared between primed and un-primed plants with and without subsequent infestation by insects. Insect bioassays will put the observed changes in gene expression and volatile emission in an ecological context, both in terms of interactions with herbivores and in terms of tritrophic interactions with natural enemies of the herbivores.

Publications

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