Plants can see, smell, and cry?

Israeli plant geneticist Daniel Chamovitz believes that plants are more similar to humans than previously realized and even have similar senses. Chamovitz is Director of Tel Aviv University’s Manna Center for Plant Biosciences, and has written a new book called What a Plant Knows detailing his findings, which may lead us to rethink what we know about biology with implications for research into food security and human diseases.

While investigating how plants respond to light, Chamovitz found a group of genes that allow plants to tell whether they are in the light or the dark. Surprisingly, these genes were later identified in humans and animals. “First, they control the circadian rhythm, the biological clock that helps our bodies keep a 24-hour schedule,” he explained. “Second, they control the cell cycle—which means we can learn more about mutations in these genes that lead to cancer.”

According to Chamovitz, plants “see” light signals, including color, direction, and intensity, and use this information to decide on a behavioral response, such as opening their leaves to absorb nutrients.

Plants also exhibit a sense of smell. For instance, a ripening fruit releases a pheromone which nearby unripe fruit can detect, triggering them to ripen too.

Plants and humans have other proteins and genes in common, such as the genes that cause breast cancer. They are therefore a potential biological model, and could be used instead of or alongside animal models for research into some human diseases.
 
In addition, eggs of insect pests deposited on plants trigger the production of scents by plants that affect different plant community members probably helping the plant to get rid of the pest before it becomes harmful. The results are reported the journal PLoS ONE.
 
Butterfly egg deposition triggers highly specific chemical and structural changes in the plant that attract different parasitic wasps attacking either butterfly eggs or caterpillars but repel egg-laying butterflies.