Plants can recognize their siblings

Washington, October 15 (ANI): In a new study led by a scientist of Indian origin, it has been determined that plants may not have eyes and ears, but they can still recognize their siblings.

The study was led by Harsh Bais, assistant professor of plant and soil sciences at the University of Delaware, US.

Earlier, in 2007, Canadian researchers found that sea rocket, a common seashore plant, can recognize its siblings - plants grown from seeds from the same mother.

Susan Dudley, an evolutionary plant ecologist at McMaster University in Hamilton, Ontario, and her colleagues observed that when siblings are grown next to each other in the soil, they "play nice" and don't send out more roots to compete with one another.

Bais, who has conducted a variety of research on plant signaling systems, read Dudley's study and wanted to find the mechanism behind the sibling recognition.

"Plants have no visible sensory markers, and they can't run away from where they are planted," Bais said. "It then becomes a search for more complex patterns of recognition," he added.

Working in his laboratory at the Delaware Biotechnology Institute, a major center for life sciences research at UD, Bais and doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.

They utilized wild populations to avoid issues with this common laboratory-bred species, which "always has cousins floating around in the lab," Bais said.

In a series of experiments, young seedlings were exposed to liquid media containing the root secretions or "exudates" from siblings, from strangers (non-siblings), or only their own exudates.

The length of the longest lateral root and of the hypocotyl, the first leaf-like structure that forms on the plant, were measured.

Additionally, in one experiment, the root exudates were inhibited by sodium orthovanadate, which specifically blocks root secretions without imparting adverse growth effects on roots.

The exposure of plants to the root exudates of strangers induced greater lateral root formation than exposure of plants to sibling exudates.

Stranger recognition was abolished upon treatment with the secretion inhibitor.

Strangers planted next to each other are often shorter, Bais notes, because so much of their energy is directed at root growth.

Because siblings aren't competing against each other, their roots are often much shallower.

Bais said that he and his colleagues also have noticed that as sibling plants grow next to each other, their leaves often will touch and intertwine compared to strangers that grow rigidly upright and avoid touching. (ANI)