Plant prompts mice to spit, spread seeds

A desert plant in Israel uses toxins to make mice spit out seeds when eating its fruit, making them seed spreaders to help the plant reproduce, researchers say. The plant in the Negev Desert, known as sweet mignonette or taily weed, uses a toxic "mustard oil bomb" to cause the desert's spiny mouse to spit out the seeds, U.S. and Israeli researchers said. "It's fascinating that these little mice are doing analytical chemistry, assaying the fruit for toxic compounds" and learning not to bite into the seed, study co-author Denise Dearing, a professor of biology at the University of Utah, said. "It adds a new dimension to our understanding of the ongoing battle between plants and animals," she said in a Utah release Thursday. "In this case, the plants have twisted the animals to do their bidding, to spread their progeny." The study is the first known case within a single species of what is known as the "directed deterrence" hypothesis in which "the fruit is trying to have itself eaten by the right consumer -- one that will spread its seeds," Dearing said. "The plant produces a fruit to deter a class of consumers that would destroy its seeds."