'Smart' Plant Virus Helps Host To Reproduce More

Plant viruses usually infect the host and kill the plant host eventually, but this discovery by Dr. John Carr and fellow scientists from the University of Cambridge described a bizarre strategy of cucumber mosaic virus that helps the host plant to reproduce more.

The cucumber mosaic virus helps stimulate the host tomato plant to produce chemical signals that attract more insect vectors, in this case aphids. However, it was observed by Dr. Carr's team that aphids is not the only arthropod affected by the chemical signals, insect pollinators also displayed altered foraging behavior. This chemical signals specifically appeal to the bumble bee species, a major pollinator of the tomato plant. This chemical signals alters the behavior of bumble bees to trick them to be more "attracted" to the infected plants than the healthy ones.

This way, just before the plant dies, the plant can spread its pollen to other plants. The virus however is not transmitted through pollination but the quality of the seed and the plant that will germinate may be reduced since the pollen came from an infected plant. Infection to plant hosts are very much harder as compared to animals since plants are non-motile and viruses can only be transmitted through insect vector bites. The virulence or the virus' ability to kill the host is not really a sustainable way for plant viruses to survive since if they are not capable of reproducing to another host, they will more likely be eradicated. This strategy ensures the survival of the virus for more generations to come.

The authors of the research suggested that the virus might be improving the pollination success of the plant that might eventually lead to reproduction success as a way to "compensate" to the low yield caused by the infection.

The researchers are currently studying the implications of the research to understand more about the behavioral patterns of insect pollinators and vectors based on the blend of chemical signals that come from the plants as well as the viral strategies of other plant viruses and how it manipulates the plant's cellular machinery to its benefit.