"The same group of proteins that plants use to decide if they are in the light or dark is also used by animals and humans," Prof. Chamovitz says. "For example, these proteins control two seemingly separate processes. First, they control the circadian rhythm, the biological clock that helps our bodies keep a 24 hour schedule. Second, they control the cell cycle which means we can learn more about mutations in these genes that lead to cancer." In experiments with fruit flies who had a mutated version of one of these genes, Prof. Chamovitz and his fellow researchers observed that the flies not only developed a fly form of leukemia, but also that their circadian rhythm was disrupted, leading to a condition somewhat like permanent jet-lag.
Plants use light as a behavioral signal, letting them know when to open their leaves to gather necessary nutrients. This response to light can be viewed as a rudimentary form of sight, contends Prof. Chamovitz, noting that the plants "see" light signals, including color, direction, and intensity, then integrate this information and decide on a response. And plants do all this without the benefit of a nervous system.
And that's not the limit of plant "senses." Plants also demonstrate smell a ripe fruit releases a "ripening pheromone" in the air, which is detected by unripe fruit and signals them to follow suit as well as the ability to feel and taste. To some degree, plants also have different forms of "memory," allowing them to encode, store, and retrieve information.
Just like us
Beyond the genes that regulate responses to light, plants and humans share a bevy of other proteins and genes for example, the genes that cause cystic fibrosis and breast cancer. Plants might not come down with these diseases, but the biological basis is the same, says Prof. Chamovitz. Because of this, plants are an excellent first stop when looking for a
|Contact: George Hunka|
American Friends of Tel Aviv University