Multiple Forms of Vector Manipulation by a Plant-Infecting Virus: Bemisia tabaci and Tomato Yellow Leaf Curl Virus

Abstract

e For many insect-vectored plant viruses, the relationship between feeding behavior and vector competence may prove integral to an understanding of the epidemiology of the resulting plant disease. While plant-infecting viruses are well known to change host plant physiology in a way that makes them more attractive to vectors, viral manipulation of the vectors themselves has only recently been reported. Previous research suggested that the rapid spread of Tomato yellow leaf curl virus (TYLCV) throughout China has been facilitated by its primary vector, the whitefly Bemisia tabaci. We conducted two experiments testing the impact of TYLCV infection of the host plant (tomato) and vector (B. tabaci biotypes B and Q) on whitefly feeding behavior. Whiteflies of biotypes B and Q both appeared to find TYLCV-infected plants more attractive, probing them more quickly and having a greater number of feeding bouts; this did not, however, alter the total time spent feeding. Viruliferous whiteflies fed more readily than uninfected whiteflies and spent more time salivating into sieve tube elements. Because vector salivation is essential for viral transmission, this virally mediated alteration of behavior should provide TYLCV a direct fitness benefit. This is the first report of such manipulation by a nonpropagative virus that belongs to an exclusively plant-infecting family of viruses (Geminiviridae). In the context of previous research showing that feeding on TYLCV-infected plants harms biotype B but helps biotype Q, the fact that both biotypes were equally affected by TYLCV also suggests that the virus may alter the biotype B-biotype Q competitive interaction in favor of biotype Q.

Insecticides promote viral outbreaks by altering herbivore competition

“…In addition, we found a positive relationship between TYLCV infection in tomato and the percentage of TYLCV-infected MED; in contrast, there was no relationship between plant health and the percentage of TYLCV-infected MEAM1. In sum, our findings are in accord with previous surveys (Pan et al 2012, Park et al 2012) and experimental work (Jiang et al 2000, Liu et al 2013a indicating that vector-plant transmission of TYLCV in Asia is predominantly associated with MED.…”

Rapid Spread of a Recently Introduced Virus (Tomato Yellow Leaf Curl Virus) and Its Vector <I>Bemisia tabaci</I> (Hemiptera: Aleyrodidae) in Liaoning Province, China

“…This hypothesis is supported by laboratory experiments (Pan et al 2012 and Þeld investigations (Chu et al 2007(Chu et al , 2010aSun et al 2009). In the laboratory, Pan et al (2012) and Liu et al (2013) found that TYLCV acquisition and transmission were greater with B. tabaci Q than with B. tabaci B. Field data concerning TYLCV and B. tabaci species in Shandong Province, China, are also consistent with our hypothesis that the rapid spread of TYLCV in China can be explained at least in part by the introduction and rapid spread of B. tabaci Q in China.…”

Novel resistance mechanisms of a wild tomato against the glasshouse whitefly

“…Tjallingii and Esch (1993)) and evidence for this is provided by elegant work using legume forisomes . That whiteflies utilise the same method has also been suggested in work by Liu et al (2013). The authors reported that B. tabaci infected with Tomato yellow leaf curl virus showed extensive salivation into sieve elements, which was interpreted as the virus affecting the ability of the whitefly to prevent sieve element occlusion to enhance the virus' transmission in watery saliva.…”