website of the Society of Plant Signaling and Behavior

 Passage 115 adapted from the website of the Society of Plant Signaling and Behavior. 0 2015 by the Society of Plant Signaling and Behavior. Passage 2 is adapted from Michael Pollan. “The Intelligent Plant.” 0 by Conde Nast. Both passage discuss plant neurobiology, the study of the sensory adaptive behavior of plants.

Passage 1

For a better understanding of the world around us, it is important that we develop and share the growing understanding of plants as dynamic and highly sensitive organisms. No longer can plants be viewed and portrayed as passive entities merely subject to environmental forces, as ‘automata’-like organisms based only on reflexes and optimised solely for accumulation of photosynthate. With a fuller understanding of signaling and communication within and among plants, it becomes clear that these sensitive biological organisms actively and competitively forage for limited resources, both above and below ground. In addition, plants accurately compute their circumstances, use sophisticated cost benefit analysis, and they take tightly controlled actions to mitigate and control diverse environmental stressors. Plants also emerge as capable of discriminating positive and negative experiences, and ‘learning’ from their past experiences. Plants use this cognitively acquired information to update their behavior in order to survive present and future challenges of their environment. Moreover, plants are also capable of refined recognition of self and non-self, and are territorial in behavior.

This Plant Neurobiological view sees plants as information-processing organisms with complex communications of various types occurring throughout the individual plant. What we need to find out is how their information is gathered and processed, what routes do data take, and how are adaptive responses integrated and coordinated, how are these events ‘remembered’ in order to allow realistic predictions of future using past experiences.

Last but not least, plants are as sophisticated in behavior as animals but this potential has been masked effectively because it operates on time scales many orders of magnitude slower than in animals. At the very least, this quality should make it easier for experimental plant scientists to uncover the mysteries of their neurobiological function and behavioral responses.

Passage 2

Many plant scientists have pushed back hard against the nascent field of plant neurobiology, beginning with a tart, dismissive letter signed by thirty-six prominent plant scientists and published Trends in Plant Science. “We begin by stating simply that there is no evidence for structures such as neurons, synapses or a brain in plants:’ the authors wrote. No such claim had actually been made—the plant neurobiology advocates had spoken only of “homologous” structures’—but the use of the word “neurobiology” in the absence of actual neurons was apparently more than many scientists could bear.

“Yes, plants have both short- and long-term electrical signalling, and they use some neurotransmitter-like chemicals as chemical signals:’ says Lincoln Taiz, an emeritus professor of plant physiology at U.C. Santa Cruz and one of the signers of the letter. “But the mechanisms are quite different from those of true nervous systems?’ Taiz says that the writings of the plant neurobiologists suffer from “over-interpretation of data, teleology, anthropomorphizing, philosophizing, and wild speculations?’ He is confident that eventually the plant behaviors we can’t yet account for will be explained by the action of chemical or electrical pathways, without recourse to “animism.” Clifford Slayman, a professor of cellular and molecular physiology at Yale, who also signed the letter, was even more blunt. ” ‘Plant intelligence’ is a foolish distraction, not a new paradigm:’ he wrote in a recent e-mail. Slayman has referred to the letter as “the last serious confrontation between the scientific community and the nuthouse on these issues?’ Scientists seldom use such language when talking about their colleagues to a journalist, but this issue generates strong feelings, perhaps because it smudges the sharp line separating the animal kingdom from the plant kingdom. The controversy is less about the remarkable discoveries of recent plant science than about how to interpret and name them: whether behaviors observed in plants which look very much like learning, memory, decision-making, and intelligence deserve to be called by those terms or whether those words should be reserved exclusively for creatures with brains.