Plants as agents: senome, electrome and the making of a plant semiosphere

For most of the history of biology, plants were treated as passive machines…

The conceptual shift described in the article sits within a broader movement that has been gathering momentum for several decades. What was once dismissed as anecdotal observation—the ability of plants to respond adaptively to stimuli, to alter their behavior based on past experience, to coordinate resources across organs—has gradually accumulated into a body of experimental work that is difficult to reconcile with a purely mechanical account of plant life. The authors’ framing of this tension is not merely rhetorical. They are pointing to a genuine epistemological problem: if the classical model of the plant as a passive automaton is inadequate, what replaces it? Their answer draws on three distinct intellectual traditions—Cellular Cognitive Biology, Biosemiotics, and Phenomenology—and the synthesis they propose is worth examining in some detail, because each tradition contributes something the others alone cannot supply.

Cellular Cognitive Biology provides the biophysical grounding. The central claim is that agency does not first appear at the level of the whole organism and then get distributed downward; rather, it is present from the very beginning, in the single cell, and is sustained by what the authors call the senome. This term, introduced in earlier work by Baluška and colleagues, refers to the totality of a cell’s sensory apparatus—the membrane receptors, ion channels, cytoskeletal elements, and associated signaling networks that together allow the cell to register and evaluate its surroundings. Crucially, the senome is described as analog and multimodal rather than digital and unimodal. This distinction matters. Digital signaling, of the kind familiar from molecular genetics, encodes information in discrete symbols that require interpretation by a downstream reader. Analog signaling, by contrast, operates through continuous variation in electrical potential, chemical concentration, and mechanical tension, allowing the cell to integrate many simultaneous inputs into a graded, real-time assessment of its situation. The senome, on this view, is not a relay station but an evaluative interface—one that already embodies a primitive form of what might be called sentience, understood not as conscious experience but as the capacity to discriminate, weigh, and respond in ways that serve the cell’s persistence.

The electrome is the second pillar of this elementary grounding. The term refers to the full complement of endogenous bioelectric activity in an organism—the resting potentials, action potentials, variation potentials, and slower electrical oscillations that propagate through membranes, plasmodesmata, and vascular tissues. Research over the past two decades has shown that these electrical dynamics are not merely byproducts of cellular metabolism but play active roles in coordinating development, wound responses, and long-distance signaling. In plants, action potentials travel through phloem and xylem-associated tissues at speeds sufficient to communicate damage from a wounded leaf to distant organs within seconds. Variation potentials, which are slower and longer-lasting, carry information about the nature and severity of the insult. Slow wave potentials and electrical oscillations in the root zone have been implicated in nutrient foraging and in the coordination of growth between root and shoot. The authors’ point is that these electrical phenomena, when integrated with mechanical and electromagnetic dynamics through the senome, constitute the physical substrate on which plant sentience operates. Without the electrome, there would be no fast, integrative, organism-wide channel of communication; with it, the plant acquires something like a nervous system’s functional equivalent, even in the absence of neurons.

The third pillar, and the one that gives the synthesis its distinctive character, is semiotics. The authors argue that bioelectric and mechanical perturbations, on their own, are just physical events—voltage changes, pressure waves, chemical gradients. They become meaningful only when they cross what the authors call a semiotic threshold, at which point they are interpreted as signs by the living system. This is where Jakob von Uexküll’s concept of the Umwelt becomes relevant. Uexküll, writing in the early twentieth century, argued that every organism inhabits a subjective world constituted by the signs that are meaningful to it. A tick, in his famous example, lives in a world composed of three signals: the smell of butyric acid, the warmth of a mammal, and the shape of a hairless surface. Everything else is irrelevant. The authors extend this insight to plants, arguing that a root tip navigating through soil does not merely respond to nutrient gradients as a physicochemical system would; it actively constructs a meaningful world—a plant Umwelt—out of the cues it encounters, organized around its metabolic needs and its ongoing project of self-maintenance. Each growth increment, on this reading, is not just a mechanical extension but a semiotic act, a step in the continuous expansion of the plant’s domain of significance.

This framing has consequences for how one understands plant behavior. If the plant is engaged in sense-making rather than mere stimulus-response, then the classical distinction between perception and action begins to blur. The root tip is simultaneously a sensory organ and a motor organ; it senses by growing, and it grows by sensing. This is what the authors mean when they describe plant cognition as embodied and enactive. The term enactivism, drawn from the work of Varela, Thompson, and Rosch, holds that cognition is not the passive reception of pre-given information but the active generation of meaning through the organism’s ongoing engagement with its environment. Applied to plants, this means that the plant does not first perceive the world and then act on it; rather, perceiving and acting are two aspects of a single process by which the plant brings forth its world. The authors’ use of the term ‘primordial metabolic concern’ captures this: the plant is not a neutral observer of its surroundings but a being whose very existence depends on finding and securing the resources—light, water, nutrients—that ‘complete’ it. This concern, they argue, is the root of intentionality in plants, understood not as conscious deliberation but as goal-directedness grounded in metabolic necessity.

The question of how agency scales from the cell to the whole organism is addressed through the concept of decentralized modular organization. Plants are not centralized systems in the way animals are. There is no command center, no single point from which all behavior is orchestrated. Instead, the plant is best understood as a federation of semi-autonomous modules—shoot apices, root tips, leaves, flowers—each with its own senome, its own capacity for local sensing and local action, and each communicating with its neighbors through electrical, chemical, and mechanical channels. The authors describe this as an integrative emergence: the agency of the whole plant is not the sum of the agencies of its parts, but something that arises from their coordination. This is a claim about the nature of biological organization that has parallels in other domains of biology, from the self-organizing properties of bacterial biofilms to the collective behavior of slime molds. In each case, the key insight is that decentralized systems can exhibit coherent, adaptive behavior without centralized control, provided that the components are capable of communicating and coordinating with one another.

The extension of this framework to the level of the holobiont—the plant together with its associated microbiome—is perhaps the most ambitious part of the synthesis. The authors introduce the concept of the N-space episenome to describe the biophysical infrastructure that enables communication between the plant and its microbial partners. At this scale, individual senomes are linked into what they call a distributed hypersenome, a network of sensing and signaling that spans multiple organisms and gives rise to what they term relational agency. The idea here is that the plant and its microbiome do not merely interact; they participate in a shared process of sense-making and decision-making that serves the survival of the whole consortium. This is consistent with a growing body of research on plant-microbe signaling, including the role of root exudates in recruiting beneficial microbes, the electrical and chemical communication that occurs within the rhizosphere, and the ways in which the plant’s immune system is modulated by its microbial partners. The holobiont concept, originally developed by Lynn Margulis and later elaborated by others, has gained traction in recent years as a way of understanding organisms as multispecies assemblages rather than isolated individuals. The authors’ contribution is to frame this assemblage in cognitive and semiotic terms, suggesting that the holobiont is not just a metabolic partnership but a distributed cognitive system.

The final section of the article turns to ethics, and this is where the synthesis moves from science into philosophy. The authors argue that if plants are agents—if they affirm their own existence as an intrinsic good—then this has implications for how humans ought to relate to them. The claim is not that plants have rights in the same sense that humans do, but that the recognition of plant agency demands a reconsideration of the moral status of the living world. This is a position that has been gaining ground in environmental philosophy, where thinkers such as Robin Wall Kimmerer, Andreas Weber, and others have argued for a more relational and less instrumental view of nature. The authors’ specific contribution is to ground this ethical claim in the biology of agency itself: if sentience and agency are intrinsic attributes of life, present from the cellular level upward, then the distinction between beings that matter morally and beings that do not becomes harder to draw. The authors advocate for the legal recognition of nature, a position that has been adopted in various forms by several countries and jurisdictions in recent years, including the granting of legal personhood to rivers, forests, and other ecosystems. Whether or not one accepts the full implications of this argument, it is clear that the biological claims on which it rests are not merely academic. They have the potential to reshape how we think about agriculture, conservation, and the place of humans in the living world.

It is worth noting that the synthesis proposed here is theoretical rather than experimental. The authors are not reporting new data; they are offering a framework for interpreting existing findings. This is a legitimate and important contribution, but it also means that the framework is open to challenge and refinement. Some biologists will resist the language of sentience and cognition when applied to organisms without nervous systems, arguing that it risks anthropomorphism or that it conflates functional responsiveness with genuine agency. Others will argue that the framework is too broad, that it risks dissolving the concept of cognition into a synonym for life itself. These are serious objections, and the authors are aware of them. Their response is to insist that the distinction between reactive and agentic systems is not a matter of complexity but of organization—that what matters is not the number of parts but the way in which those parts are coordinated to sustain a self-maintaining identity. Whether this distinction holds up under further scrutiny is a question that will require both theoretical refinement and empirical investigation. What is clear is that the framework offers a coherent and biologically grounded alternative to the mechanistic paradigm that has dominated plant science for centuries, and that it opens new avenues for research into the cellular and organismal bases of plant behavior.

Subject of Research: Theoretical framework proposing that plant agency arises from cellular sentience, bioelectric signaling and distributed cognition across scales.

Article Title: Plant agency: from senome and electrome to plant semiosphere

Article References: Basso, L. F., Baluška, F., & Souza, G. M. (2026). Plant agency: from senome and electrome to plant semiosphere. Frontiers in Plant Physiology, 4, Article 1861112. https://doi.org/10.3389/fphgy.2026.1861112

Image Credits: AI Generated

DOI: 10.3389/fphgy.2026.1861112

Keywords: plant physiology, biosemiotics, plant cognition, electrome, holobiont, environmental ethics, Plant, agency, senome, semiosphere, scientific research