Mikania Micrantha Wilt Virus Alters Insect Vector's Host Preference to Enhance Its Own Spread.

Wang Wang,Elzaki Elzaki,Zhang Zhang,Huang Huang,Chen Chen,Liu Liu,Zhu-Salzman Zhu-Salzman,Ma Ma

doi:10.3390/v11040336

Abstract

As an invasive weed, Mikania micrantha 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 Myzus persicae (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.

Highlights

Mikania micrantha Kunth (Asteraceae), commonly known as mile-a-minute weed, is a perennial vine
Odor from Mikania micrantha wilt virus (MMWV)-Infected Plants is More Attractive to Aphids
To determine the potential of volatiles in host preference of M. persicae, healthy, mock-inoculated, or MMWV-infected plants were evaluated in choice tests using a Y-tube olfactometer

Summary

Introduction

Mikania micrantha Kunth (Asteraceae), commonly known as mile-a-minute weed, is a perennial vine. Native to Central and South America, it has become an important invasive weed in the Southeast Asia and Pacific regions [1]. Among the 10 worst weeds in the world, M. micrantha is a serious threat to the functioning local ecosystems and global biodiversity [1,2,3,4]. Due to its rapid growth, wide ecophysiological tolerance, strong reproduction, high phenotypic plasticity, and allelopathic inhibitory effect on neighboring plants [1,5], M. micrantha invasion in Southern China has caused substantial damage to natural ecosystems [1,2,5]. No single method can effectively reduce the losses caused by M. micrantha [1,2,3]

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Conclusion