Enhanced virulence of Fusarium species associated with spear rot of oil palm following recovery from osmotic stress

5Citations
Citations of this article
16Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

Fusarium spp., which are common inhabitants of oil palm leaves, are weak pathogens of common spear rot (CSR). We investigated the influence of osmotic stress on the growth, virulence, and activity of cell wall-degrading enzymes of CSR fungi, using potato dextrose agar (PDA) supplemented with KCl or sucrose (hyperosmotic medium). Hyperosmotic stress significantly inhibited mycelial growth, but growth rapidly recovered when mycelia were transferred to control medium. When inoculated into oil palm spear leaflets, Fusarium sp., and F. incarnatum precultured on 1.0 and 1.5 M KCl-hyperosmotic medium induced lesions that were two to four times larger than those in non-stressed cultures, suggesting enhanced virulence of the weak pathogens. Lesion size was not greatly affected in hyperosmotic cultures of moderately virulent F. sacchari. No activity of pectin lyase was detected in liquid cultures of the Fusarium isolates. All isolates except F. incarnatum BT48 secreted polygalacturonase (PG), which was active in both liquid cultures and inoculated leaves. Significantly increased PG activity (5–32-fold) was observed on leaves inoculated with hyperosmotic cultures of Fusarium sp. and F. sacchari. These findings suggest that Fusarium sp., F. incarnatum, and F. sacchari exhibit an adaptive physiological plasticity to hyperosmotic stress that results in enhanced virulence.

Cite

CITATION STYLE

APA

Suwandi, S., Akino, S., & Kondo, N. (2018). Enhanced virulence of Fusarium species associated with spear rot of oil palm following recovery from osmotic stress. Mycology, 9(1), 20–28. https://doi.org/10.1080/21501203.2017.1336497

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free