Host plants communicate warning signals through a parasite network, when insects attack

A team of scientists from the Kunming Institute of Botany in China and the Max Planck Institute for Chemical Ecology in Jena has discovered that parasitic plants of the genus Cuscuta (dodder) not only deplete nutrients from their host plants, but also function as important “information brokers” among neighboring plants, when insects feed on host plants. Dodder, a parasitic vine, grows rapidly, entwining and parasitizing its host plants by inserting haustoria (a special organ that only parasitic plants have and functions somewhat similarly as roots) into the host plants’ stems. The dodder vines can often connect different host plants together forming a network. If any plant in the network is attacked by herbivores, expressions of defense genes in the unattacked neighboring plants are activated. The plants are now on alert and become more resistant to their enemies.