ABSTRACT
As an invasive weed, Mikaniamicrantha Kunth has caused serious damage to natural forest ecosystems in South China in recent years. Mikania micrantha wilt virus (MMWV), an isolate of the Gentian mosaic virus (GeMV), is transmitted by Myzuspersicae (Sulzer) in a non-persistent manner and can effectively inhibit the growth of M. micrantha. To explore the MMWV-M. micrantha-M. persicae interaction and its impact on the invasion of M. micrantha, volatile compounds (VOCs) emitted from healthy, mock-inoculated, and MMWV-infected plants were collected, and effects on host preference of the apterous and alate aphids were assessed with Y-shaped olfactometers. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that MMWV infection changed the VOC profiles, rendering plants more attractive to aphids. Clip-cages were used to document the population growth rate of M.persicae fed on healthy, mock-inoculated, or MMWV-infected plants. Compared to those reared on healthy plants, the population growth of M. persicae drastically decreased on the MMWV-infected plants. Plant host choice tests based on visual and contact cues were also conducted using alate M.persicae. Interestingly, the initial attractiveness of MMWV-infected plants diminished, and more alate M. persicae moved to healthy plants. Taken together, MMWV appeared to be able to manipulate its plant host to first attract insect vectors to infected plants but then repel viruliferous vectors to promote its own dispersal. Its potential application for invasive weed management is discussed.
Subject(s)
Aphids/physiology , Fabavirus/growth & development , Feeding Behavior/drug effects , Host Microbial Interactions , Host Specificity/drug effects , Mikania/virology , Pheromones/metabolism , Animals , Aphids/drug effects , China , Insect Vectors/drug effects , Insect Vectors/physiology , Plant Diseases/virology , Volatile Organic Compounds/metabolismABSTRACT
The complete RNA genomic sequence of a new virus infecting Mikania micrantha, designated as Mikania micrantha wilt virus (MMWV), has been determined. The genomic sequence and the predicted gene products of MMWV were similar to those of the other viruses of the genus Fabavirus. The MMWV nucleotide sequence showed 75.6% identity to that of gentian mosaic virus, 56.6 and 57% identity to those of two Broad bean wilt virus 1 isolates, and between 55.7 and 58% identity to those of seven Broad bean wilt virus 2 isolates. Our results suggested that MMWV represents a distinct isolate of the candidate species Gentian mosaic virus.