RESUMO
Citrus canker, which is caused by Xanthomonas citri, is a severe disease that affects citrus plants worldwide. This paper aimed to compare, for the first time, the chemical composition and anti-Xanthomonas citri activities of essential oils from Schinus molle fresh and dry leaves (EO-FL and EO-DL, respectively). Anti-X. citri activity of spathulenol, the major constituent of oils, was also evaluated. Activities were screened by the broth microdilution method on 96-well culture plates. Three major constituents were identified in EO-FL and EO-DL by GC-MS and GC-FID: spathulenol, ß-caryophyllene and caryophyllene oxide. EO-DL (MIC = 31.25 µg/mL), EO-FL (MIC = 62.5 µg/mL) and spathulenol (MIC = 100 µg/mL) were active against X. citri strains (resistant, tolerant and sensitive to copper). Even though results showed that in vitro potential of EO-FL, EO-DL and spathulenol against X. citri, further in vivo studies are needed to prove their applicability to the biocontrol of citrus canker.
RESUMO
Infection of wMel Wolbachia in Aedes aegypti imparts two signature features that enable its application for biocontrol of dengue. First, the susceptibility of mosquitoes to viruses such as dengue and Zika is reduced. Second, a reproductive manipulation is caused that enables wMel introgression into wild-type mosquito populations. The long-term success of this method relies, in part, on evolution of the wMel genome not compromising the critical features that make it an attractive biocontrol tool. This study compared the wMel Wolbachia genome at the time of initial releases and 1-7 years post-release in Cairns, Australia. Our results show the wMel genome remains highly conserved up to 7 years post-release in gene sequence, content, synteny and structure. This work suggests the wMel genome is stable in its new mosquito host and, therefore, provides reassurance on the potential for wMel to deliver long-term public-health impacts.