Plants can adapt to many different difficulties and challenges, but so far there have been less known abilities of plants to take advantage of environmental information related to stress from neighboring plants. In a study recently published in PLoS one and entitled “Rumor Has It…: Relay Communication of Stress Cues in Plants” carried out at the Jacob Blaustein Institutes for Desert Research (BIDR) by the research group of Prof. Ariel Novoplansky of the Mitrani Department of Desert Ecology in collaboration with Dr. Omer Falik and Yonat Mordoch of the same Department, and Lydia Quansah and Dr. Aaron Fait of the French Associates Institute for Agriculture and Biotechnology of Dryland, the researchers exposed plants to different stresses such as drought or salt and found that shortly after exposure to stress, their neighbors who were not exposed reacted as if exposed to stress themselves.
Evidence demonstrates that plants are able not only to perceive and adaptively respond to external information but also to anticipate forthcoming perils and stresses, according to Novoplansky. “We tested the hypothesis that unstressed plants are able to respond to stress cues emitted from their stressed neighbors and, in turn, induce stress responses in additional unstressed plants located further away from the stressed plants,” he says.
Pisum sativum (garden pea) plants were subjected to drought with neighboring rows of unstressed plants on either side, with which they could exchange different cue combinations. On one side, the stressed plant and its unstressed neighbors did not share their rooting volumes (unshared) and thus were limited to shoot communication. On its other side, the stressed plant shared one of its rooting volumes with its nearest unstressed neighbor and all plants shared their rooting volumes with their immediate neighbors (shared), allowing both root and shoot communication.
Fifteen minutes following drought induction, significant stomatal closure was observed in both the stressed plants and their nearest unstressed shared neighbors, and within one hour, all shared neighbors closed their stomata. Stomatal closure was not observed in the unshared neighbors. “The results demonstrate that unstressed plants are able to perceive and respond to stress cues emitted by the roots of their drought-stressed neighbors and, via ‘relay cuing’, elicit stress responses in further unstressed plants. Further work is underway to study the underlying mechanisms of this new mode of plant communication and its possible adaptive implications for the anticipation of forthcoming abiotic stresses by plants,” he says.
For further reading: Rumor Has It