Analysis of the Role of <i>Bradysia impatiens</i> (Diptera: Sciaridae) as a Vector Transmitting Peanut Stunt Virus on the Model Plant <i>Nicotiana benthamiana</i>

• Main Authors: Marta Budziszewska, Patryk Frąckowiak, Aleksandra Obrępalska-Stęplowska
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Cells
• Subjects: virus transmission; cucumovirus; fungus gnat; plant-insect-virus interactions; virus detection; virus vector
• Online Access: https://www.mdpi.com/2073-4409/10/6/1546

<i>Bradysia</i> species, commonly known as fungus gnats, are ubiquitous in greenhouses, nurseries of horticultural plants, and commercial mushroom houses, causing significant economic losses. Moreover, the insects from the <i>Bradysia</i> genus have a well-documented role in plant pathogenic fungi transmission. Here, a study on the potential of <i>Bradysia impatiens</i> to acquire and transmit the peanut stunt virus (PSV) from plant to plant was undertaken. Four-day-old larvae of <i>B. impatiens</i> were exposed to PSV-P strain by feeding on virus-infected leaves of <i>Nicotiana benthamiana</i> and then transferred to healthy plants in laboratory conditions. Using the reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR (RT-qPCR), and digital droplet PCR (RT-ddPCR), the PSV RNAs in the larva, pupa, and imago of <i>B. impatiens</i> were detected and quantified. The presence of PSV genomic RNA strands as well as viral coat protein in <i>N. benthamiana</i>, on which the viruliferous larvae were feeding, was also confirmed at the molecular level, even though the characteristic symptoms of PSV infection were not observed. The results have shown that larvae of <i>B. impatiens</i> could acquire the virus and transmit it to healthy plants. Moreover, it has been proven that PSV might persist in the insect body transstadially. Although the molecular mechanisms of virion acquisition and retention during insect development need further studies, this is the first report on <i>B. impatiens</i> playing a potential role in plant virus transmission.