Chitosan primes plant defence mechanisms against Botrytis cinerea, including expression of Avr9/Cf‐9 rapidly elicited genes

• DOI: 10.1111/pce.13921
• Publication Date: 2020-10-23T10:54:09Z
• Authors: Daniel De Vega; Nicola Holden; Pete E Hedley; Jenny Morris; Estrella Luna; Adrian Newton
• Keywords: name=Physiology; Nicotiana; /dk/atira/pure/subjectarea/asjc/1300/1314; 570; Blotting, Western; /dk/atira/pure/subjectarea/asjc/1100/1110; Arabidopsis; Solanum lycopersicum (tomato); induced resistance; transcriptomics; 03 medical and health sciences; Solanum lycopersicum; 615; Cloning, Molecular; Glucans; Solanaceae; Disease Resistance; Plant Diseases; 2. Zero hunger; Chitosan; 0303 health sciences; Microscopy, Confocal; Gene Expression Profiling; Original Articles; Plants, Genetically Modified; Botrytis cinerea (Grey mould); Botrytis; chitosan; defence priming; name=Plant Science; callose

AbstractCurrent crop protection strategies against the fungal pathogen Botrytis cinerea rely on a combination of conventional fungicides and host genetic resistance. However, due to pathogen evolution and legislation in the use of fungicides, these strategies are not sufficient to protect plants against this pathogen. Defence elicitors can stimulate plant defence mechanisms through a phenomenon known as defence priming. Priming results in a faster and/or stronger expression of resistance upon pathogen recognition by the host. This work aims to study defence priming by a commercial formulation of the elicitor chitosan. Treatments with chitosan result in induced resistance (IR) in solanaceous and brassicaceous plants. In tomato plants, enhanced resistance has been linked with priming of callose deposition and accumulation of the plant hormone jasmonic acid (JA). Large‐scale transcriptomic analysis revealed that chitosan primes gene expression at early time‐points after infection. In addition, two novel tomato genes with a characteristic priming profile were identified, Avr9/Cf‐9 rapidly elicited protein 75 (ACRE75) and 180 (ACRE180). Transient and stable over‐expression of ACRE75, ACRE180 and their Nicotiana benthamiana homologs, revealed that they are positive regulators of plant resistance against B. cinerea. This provides valuable information in the search for strategies to protect Solanaceae plants against B. cinerea.