Fungitoxic effect of scopolin and related coumarins on Sclerotinia sclerotiorum. A way to overcome sunflower head rot

Authors: Prats, E.; Bazzalo, M.; León, A.; Jorrín, J.

Source: Euphytica, Volume 147, Number 3, February 2006 , pp. 451-460(10)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

Abstract:

The content of coumarins, as probable phytoalexins, was analysed in four sunflower genotypes that ranged in responses to head rot from highly susceptible to highly resistant. Low levels of all coumarins (scopolin, scopoletin and ayapin) were detected in the three most susceptible genotypes irrespective of time after inoculation. However, in the resistant genotype there was a clear time-dependent disease-induced increase of all coumarins that reached a maximum after 10-14 days. Detailed comparison of the most susceptible and the resistant genotype showed that in the resistant but not the susceptible, scopoletin peroxidase activity increased during the course of the experiment. Results confirmed a clear negative correlation between coumarin content and disease symptoms and in particular for scopolin. Furthermore we show for the first time that scopolin is inhibitory to Sclerotinia at similar doses to scopoletin. As scopolin is known to be less phytotoxic than ayapin and scopoletin, its accumulation may well confer head rot resistance with minimal plant damage and might be one of the bases for resistance to Sclerotinia.

Keywords: coumarins; Helianthus annuus L.; phytoalexins; Sclerotinia sclerotiorum; sunflower

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s10681-005-9045-8

Affiliations: 1: Email: bb2prpee@uco.es

Publication date: 2006-02-01