Virus infection usually makes a plant sick and inhibits its growth. Nevertheless, virus infection may also offer a surprising boost for reproduction.
Scientists newly find that infected plants release a smell different from healthy ones. This unique smell can attract more bees to their flowers and make more seeds. The finding is published in PLOS Pathogens.
In the study, researchers examined the impact of virus (Cucumber mosaic virus) on tomato plants.
The result showed that virus infection caused changes in plant smell emission. This made tomato flowers more attractive to bumblebees. Bumblebees are important pollinators for tomato plants (pollinators are insects that fertilize a plant with pollen).
Although tomato flowers could give rise to seed through self-fertilization, bumblebees enhanced fertilization and increased the number of seeds produced per fruit.
Mathematical analyses showed that when infected tomato plants had higher self-fertilization and their pollen transfer increased, they had better reproduction than competitors.
Researchers suggest that under natural conditions, when virus infects a plant, it may “payback” the plant by encouraging insects to fertilize the plant. This can enhance competitiveness of the plant and inhibit resistant plant strains.
Usually, viral infected plants yield less seeds than healthy plants. But with the “payback” of the virus, the plants can produce more seeds than before, which compensates for the loss.
Citation: Groen SC et al. (2016). Virus Infection of Plants Alters Pollinator Preference: A Payback for Susceptible Hosts? PLoS Pathogens, 12: e1005790. doi: 10.1371/journal.ppat.1005790.
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