Gall-formers are parasitic organisms that manipulate plant traits for their own benefit. Galls have been shown to protect their inhabitants from natural enemies such as predators and parasitoids by various chemical and mechanical means. Little attention, however, has been given to the possibility of defense against microbial pathogens in the humid and nutrient-rich gall environment. We found that the large, cauliflower-shaped, galls induced by the aphid Slavum wertheimae on buds of Pistacia atlantica trees express antibacterial and antifungal activities distinct from those found in leaves. Antibacterial activity was especially profound against Bacillus spp (a genus of many known insect pathogen) and against Pseudomonas aeruginosa (a known plant pathogen). Antifungal activity was also demonstrated against multiple filamentous fungi. Our results provide evidence for the protective antimicrobial role of galls. This remarkable antibacterial and antifungal activity in the galls of S. wertheimae may be of agricultural and pharmaceutical value.
Bibliographical noteFunding Information:
weight was 49 (±5) mg. Cultures were allowed to grow for 24 to 48 h at 30°C, and growth inhibition was estimated by measuring three randomly selected diameters around the disk. All experiments were performed in triplicate, except for the experiments The authors thank Dr. Tamar Keasar and Prof. Ido Izhaki for fruitful discussions and assistance with the statistical analysis. We also thank Dr. Shai Markman for valuable comments on the manuscript. This research was supported by The Israel Science Foundation (grant No. 940/08 to M.I.) and by the Oranim college seed money grant program.
- Multiple defenses
- Secondary metabolites
- Slavum wertheimae
ASJC Scopus subject areas
- Plant Science