The Natural Product Citral Can Cause Significant Damage to the Hyphal Cell Walls of Magnaporthe grisea

Abstract

Abstract:In order to find a natural alternative to the synthetic fungicides currently used against the devastating rice blast fungus, Magnaporthe grisea, this study explored the antifungal potential of citral and its mechanism of action. It was found that citral not only inhibited hyphal growth of M. grisea, but also caused a series of marked hyphal morphological and structural alterations. Specifically, citral was tested for antifungal activity against M. grisea in vitro and was found to significantly inhibit colony development and mycelial growth with IC 50 and IC 90 values of 40.71 and 203.75 μg/mL, respectively. Furthermore, citral reduced spore germination and germ tube length in a concentration-dependent manner. Following exposure to citral, the hyphal cell surface became wrinkled with folds and cell breakage that were observed under scanning electron microscopy (SEM). There was damage to hyphal cell walls and membrane structures, loss of villous-like material outside of the cell wall, thinning of the cell wall, and discontinuities formed in the cell membrane following treatment based on transmission electron microscopy (TEM). This increase in chitinase activity both supports the morphological changes seen in the hyphae, and also suggests a mechanism of action. In conclusion, citral OPEN ACCESSMolecules 2014, 19 10280 has strong antifungal properties, and treatment with this compound is capable of causing significant damage to the hyphal cell walls of M. grisea.

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“…Citral was able to inhibit conidia germination, suppress germ tube elongation, restrain mycelium growth, and prevent colony development in a concentration-dependent manner in vitro. After exposure to citral, the surface of mycelium cells observed under a scanning electron microscope (SEM) became wrinkled, the mycelium cell wall became thin, the cell membran was impaired, and the villus-like material outside the cell wall was lost (29). Sha et al studied the interactions between two B. subtilis strains SYX04 and SYX20 and M. oryzae.…”

Natural plant volatiles as an alternative approach to control stem‐end rot in avocado cultivars

“…Li et al. () demonstrated that citral was capable of inhibiting mycelial growth, conidial formation and germination, appressorium formation and damaging the hypha cell walls of M. grisea . Tao, Jia, et al.…”

“…Each treatment contained four replicates and at least 100 spores per treatment were examined under the light microscope (Leica DM 3,000, Leica microsystem, Germany) at 40 × magnification after each exposure to the plant volatile and the number of germinated spores per replicate was determined. The germination and inhibition percentage was calculated as described by Li, Wu, Yin, Liang, and Li () using the formula: where Sc is the average number of spore germinated in the control trials and St is the average number of spore germinated in the treated trials.…”

Isolation, identification, and optimal cultivation of a marine bacterium antagonistic to Magnaporthe grisea

“…The disease can cause harm to rice throughout the year and can occur on various parts of the plant. Global annual rice yield losses caused by M. grisea range from 11 to 30% (Tang et al, 2013;Li et al, 2014;Zhu et al, 2014;Shanmugapackiam et al, 2015), and infection can even cause crop failure. Spores are mainly responsible for infection (Choi et al, 2013;Motallebi et al, 2013;Li et al, 2014;Nehls and Dietz, 2014;Babu et al, 2015).…”