Teleosemantics is the view that semantic classification is a species of functional classification. While it is plausible, I think, that there are semantic functions in the natural world, I want to suggest that not all semantic states are functional. An assumption commonly endorsed by the teleosemantist is that there is a distinction between accidental or incidental contributory effects and functions. However, endorsing that distinction, I will suggest, implies the theoretical possibility of nonfunctional semantics. In fact, plant-to-plant signaling (...) might be an actual instance of that theoretical possibility. (shrink)

There is an urgent need for novel protection strategies to sustainably secure crop production under changing climates. Studying microbial effectors, defined as microbe‐derived proteins that alter signalling inside plant cells, has advanced our understanding of plant immunity and microbial plant colonisation strategies. Our understanding of effectors in the establishment and beneficial outcome of plant symbioses is less well known. Combining functional and comparative interaction assays uncovered specific symbiont effector targets in highly interconnected plant signalling networks (...) and revealed the potential of effectors in beneficially modulating plant traits. The diverse functionality of symbiont effectors differs from the paradigmatic immuno‐suppressive function of pathogen effectors. These effectors provide solutions for improving crop resilience against climate stress by their evolution‐driven specification in host protein targeting and modulation. Symbiont effectors represent stringent tools not only to identify genetic targets for crop breeding, but to serve as applicable agents in crop management strategies under changing environments. (shrink)

Steroid hormones are signaling molecules important for normal growth, development and differentiation of multicellular organisms. Brassinosteroids (BRs) are a class of polyhydroxylated steroids that are necessary for plant development. Molecular genetic studies in Arabidopsis thaliana have led to the cloning and characterization of the BR receptor, BRI1, which is a transmembrane receptor serine/threonine kinase. The extracellular domain of BRI1, which is composed mainly of leucine‐rich repeats, can confer BR responsivity to heterologous cells and is required for BR binding. (...) Although downstream components of BR action are mostly unknown, multiple genes whose expression are regulated by BRs have been identified and suggest mechanisms by which BRs affect cell elongation and division. BioEssays 23:1028–1036, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

The exploration of plant behavior on a cellular scale in a minimal invasive manner is key to understanding plant adaptations to their environment. Plant hormones regulate multiple aspects of growth and development and mediate environmental responses to ensure a successful life cycle. To monitor the dynamics of plant hormone actions in intact tissue, we need qualitative and quantitative tools with high temporal and spatial resolution. Here, we describe a set of biological instruments (reporters) for the analysis (...) of the distribution and signaling of various plant hormones. Furthermore, we provide examples of their utility for gaining novel insights into plant hormone action with a deeper focus on the drought hormone abscisic acid. (shrink)

Volatile compounds, such as nitric oxide and ethylene gas, play a vital role as signaling molecules in organisms. Ethylene is a plant hormone that regulates a wide range of plant growth, development, and responses to stress and is perceived by a family of ethylene receptors that localize in the endoplasmic reticulum. Constitutive Triple Response 1 (CTR1), a Raf‐like protein kinase and a key negative regulator for ethylene responses, tethers to the ethylene receptors, but undergoes nuclear translocation upon (...) activation of ethylene signaling. This ER‐to‐nucleus trafficking transforms CTR1 into a positive regulator for ethylene responses, significantly enhancing stress resilience to drought and salinity. The nuclear trafficking of CTR1 demonstrates that the spatiotemporal control of ethylene signaling is essential for stress adaptation. Understanding the mechanisms governing the spatiotemporal control of ethylene signaling elements is crucial for unraveling the system‐level regulatory mechanisms that collectively fine‐tune ethylene responses to optimize plant growth, development, and stress adaptation. (shrink)

We analyse managerial discourse in corporate communication (‘CEO-speak’) during a 6-month period following a legitimacy-threatening event in the form of an incident in a German nuclear power plant. As discourses express specific stances expressed by a group of people who share particular beliefs and values, they constitute an important means of restoring organisational legitimacy when social rules and norms have been violated. Using an analytical framework based on legitimacy as a process of reciprocal sense-making and consisting of three levels (...) of analysis which capture the relationship between text and context, we investigate the discourse used by CEOs in their initial and subsequent accounts of the incident. We find that CEOs aim to negotiate a resolution between their initial account and organisational audiences’ incongruent interpretations of the event by adopting an ad hoc normative attitude to stakeholders. This manifests itself in the strategic use of the discourse of stakeholder engagement as a means of signalling change, yet maintaining the status quo. It suggests that CEOs strategically use discourse to manufacture organisational audiences’ consent regarding the continued operation of the nuclear power plant affected by the incident. Our findings contribute to the critical corporate communication literature which regards corporate narrative reporting as a means of consolidating the private interests of corporations, rather than increasing transparency and accountability. (shrink)

‘Plant neurobiology’ has emerged in recent years as a multidisciplinary endeavor carried out mainly by steady collaboration within the plant sciences. The field proposes a particular approach to the study of plant intelligence by putting forward an integrated view of plant signaling and adaptive behavior. Its objective is to account for the way plants perceive and act in a purposeful manner. But it is not only the plant sciences that constitute plant neurobiology. Resources (...) from philosophy and cognitive science are central to such an interdisciplinary project, if plant neurobiology is to maintain its target well-focused. This manifesto outlines a road map for the establishment and development of a new subject—the Philosophy of Plant Neurobiology—, a new field of research emerging at the intersection of the philosophy of cognitive science and plant neurobiology. The discipline is herewith presented, introducing challenges and novel lines of engagement with the empirical investigation, and providing an explanatory framework and guiding principles that will hopefully ease the integration of research on the quest for plant intelligence. (shrink)

‘Plant neurobiology’ has emerged in recent years as a multidisciplinary endeavor carried out mainly by steady collaboration within the plant sciences. The field proposes a particular approach to the study of plant intelligence by putting forward an integrated view of plant signaling and adaptive behavior. Its objective is to account for the way plants perceive and act in a purposeful manner. But it is not only the plant sciences that constitute plant neurobiology. Resources (...) from philosophy and cognitive science are central to such an interdisciplinary project, if plant neurobiology is to maintain its target well-focused. This manifesto outlines a road map for the establishment and development of a new subject—the Philosophy of Plant Neurobiology—, a new field of research emerging at the intersection of the philosophy of cognitive science and plant neurobiology. The discipline is herewith presented, introducing challenges and novel lines of engagement with the empirical investigation, and providing an explanatory framework and guiding principles that will hopefully ease the integration of research on the quest for plant intelligence. (shrink)

Darwin1 introduced the idea that ornamental secondary sexual traits have evolved in response to female preferences for showy males. Among such traits, yellow and red carotenoid‐based ornaments have been considered as particularly good candidates for explaining why and how females would benefit from mating with showy partners. Because carotenoids can be used for promotion of both health and appearance, colourful male ornaments should honestly reveal the vigour of the bearers. Two recent experiments with birds2,3 now show how allocation of bodily (...) carotenoids to sexual signalling is traded off against the use of carotenoids for boosting immune function. BioEssays 25:746–747, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Numerous and diverse reports indicate the efficacy of shamanic plant adjuncts (e.g., iboga, ayahuasca, psilocybin) for the care and treatment of addiction, post-traumatic stress disorder, cancer, cluster headaches, and depression. This article reports on a first-person healing of lifelong asthma and atopic dermatitis in the shamanic context of the contemporary Peruvian Amazon and the sometimes digital ontology of online communities. The article suggests that emerging language, concepts, and data drawn from the sciences of plant signaling and behavior (...) regarding “plant intelligence” provide a useful heuristic framework for comprehending and actualizing the healing potentials of visionary plant “entheogens” (Wasson 1971) as represented both through first-person experience and online reports. Together with the paradigms and practices of plant signaling, biosemiotics provides a robust and coherent map for contextualizing the often reported experience of plant communication with ayahuasca and other entheogenic plants. The archetype of the “plant teachers” (called Doctores in the upper Amazon) is explored as a means for organizing and interacting with this data within an epistemology of the “hallucination/perception continuum (Fischer 1975). “Ecodelic” is offered as a new linguistic interface alongside “entheogen” (Wasson 1971). (shrink)

Arbuscular mycorrhiza (AM), a type of plant‐fungal endosymbiosis, and nodulation, a bacterial‐plant endosymbiosis, are the most ubiquitous symbioses on earth. Recent findings have established part of a shared genetic basis underlying these interactions. Here, we approach root endosymbioses through the lens of the homology and modularity concepts aiming at further clarifying the proximate and ultimate causes for the establishment of these biological systems. We review the genetics that underlie interspecific signaling and its concomitant shift in genetic programs (...) for either partner. Also, through the comparative analysis of genetic modules shared by AM and nodulation symbioses, we identify fundamental nodes in these networks, suggesting the elemental steps that may have permitted symbiotic adaptation. Here, we show that this approach, allied to recent technical advances in the study of genetic systems architecture, can provide clear testable hypotheses for the advancement of our understanding on the evolution and development of symbiotic systems. (shrink)

Because of its elegant simplicity, the Arabidopsis root has become a model for studying plant organogenesis. In this review we focus on recent results indicating the importance of signaling in root development. A role for positional information in root cell specification has been demonstrated by ablation analyses. Through mutational analysis, genes have been identified that play a role in radial pattern formation. The embryonic phenotypes of these mutants raised the possibility that division patterns in post‐embryonic roots are dependent (...) on signaling that originates during embryonic development. Analysis of expression of the SCARECROW gene indicates that it may play a role in this ‘top‐down’ signaling process. Characterization of root epidermis development has led to the identification of negative regulators of root‐hair formation. These appear to set up a prepattern which is reinforced by signaling by plant hormones. (shrink)

This book assembles recent research on memory and learning in plants. Organisms that share a capability to store information about experiences in the past have an actively generated background resource on which they can compare and evaluate coming experiences in order to react faster or even better. This is an essential tool for all adaptation purposes. Such memory/learning skills can be found from bacteria up to fungi, animals and plants, although until recently it had been mentioned only as capabilities of (...) higher animals. With the rise of epigenetics the context dependent marking of experiences on the genetic level is an essential perspective to understand memory and learning in organisms. -/- Plants are highly sensitive organisms that actively compete for environmental resources. They assess their surroundings, estimate how much energy they need for particular goals, and then realize the optimum variant. They take measures to control certain environmental resources. They perceive themselves and can distinguish between ‘self’ and ‘non-self’. They process and evaluate information and then modify their behavior accordingly. -/- The book will guide scientists in further investigations on these skills of plant behavior and on how plants mediate signaling processes between themselves and the environment in memory and learning processes. (shrink)

The juvenile hormones of insects regulate an unusually large diversity of processes during postembryonic development and adult reproduction. It is a long‐standing puzzle in insect developmental biology and physiology how one hormone can have such diverse effects. The search for molecular mechanisms of juvenile hormone action has been guided by classical models for hormone–receptor interaction. Yet, despite substantial effort, the search for a juvenile hormone receptor has been frustrating and has yielded limited results. We note here that a number of (...) lipid‐soluble signaling molecules in vertebrates, invertebrates and plants show curious similarities to the properties of juvenile hormones of insects. Until now, these signaling molecules have been thought of as uniquely evolved mechanisms that perform specialized regulatory functions in the taxon where they were discovered. We show that this array of lipid signaling molecules share interesting properties and suggest that they constitute a large set of signal control and transduction mechanisms that include, but range far beyond, the classical steroid hormone signaling mechanism. Juvenile hormone is the insect representative of this widespread and diverse system of lipid signaling molecules that regulate protein activity in a variety of ways. We propose a synthetic perspective for understanding juvenile hormone action in light of other lipid signaling systems and suggest that lipid activation of proteins has evolved to modulate existing signal activation and transduction mechanisms in animals and plants. Since small lipids can be inserted into many different pathways, lipid‐activated proteins have evolved to play a great diversity of roles in physiology and development. BioEssays 25:994–1001, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Light mediates plant development partly by orchestrating changes in gene expression, a process which involves a complex combination of positive and negative signaling cascades. Genetic investigations using the small crucifer Arabidopsis thaliana have demonstrated a fundamental role for the down‐regulation of light‐inducible genes in response to darkness, thus offering a suitable model system for investigating how plants repress gene expression in a developmental context. Rapid progress in eukaryotic gene repression mechanisms in general, and light control of plant (...) gene expression in particular, sheds new light on how a class of ten pleiotropic COP/DET/FUS genes might function to down‐regulate light‐inducible genes in plants. (shrink)

Most land plants associate with mycorrhizal fungi that can connect roots of neighboring plants in common mycelial networks (CMNs). Recent evidence shows that CMNs transfer warning signals of pathogen and aphid attack between plants. However, we do not know how defence‐related signaling via CMNs operates or how ubiquitous it is. Nor do we know what the ecological relevance and fitness consequences are, particularly from the perspective of the mycorrhizal fungus. Here, we focus on the potential fitness benefits for mycorrhizal (...) fungi and outline hypothetical scenarios in which signal transfer via CMNs is modulated in order to acquire the most benefit for the fungus (i.e. acquisition of carbon) for minimal cost. We speculate that the signal may be quantitative and may elicit plant defence responses on different levels depending on the distance the signal is transferred. Finally, we discuss the possibility of practical applications of this phenomenon for crop protection. (shrink)

Systems thinking is an increasingly recognized paradigm in education in both natural and social sciences, a particular focus being, naturally, in biology. This article argues that plant biology, and in particular, plant hormonal signaling, provides highly illustrative models for learning and teaching in a systems paradigm, because it offers examples of highly complex networks, ranging from the molecular‐ to ecosystem‐scale, and in addition lends itself to the use of real‐life biological objects.

Thinking of the animal-as-non-human is an idea that does not solely belong to a myopic yet ameliorable moment of Western philosophy’s past. It is central to, even constitutive of that past. It remains characteristic of its present and will likely dominate the character of philosophy—of thinking’s—foreseeable future. My contention is that thinking-difference has not, and cannot happen because of thinking-the-animal, and this is precisely due to the conceptual companionship that animality has played between the human and the non-human. This paper (...) explores thinking otherwise-thananimality through the activation of the Deleuzo-Guattarian concept of becoming-plant. Plant life is genuinely heterogeneous to animal life. In this paper I explore the complex phenomenon of plant communication. Thinking through and activating the vital difference expressed by plant signalling can play a role in the activation of real difference in thought, not merely its companionable extension. (shrink)

Plants growing in temperate regions are able to survive freezing temperatures from −5° to −30°C, depending on the species, through a process known as cold acclimation. In the last decade much work has been done on the molecular mechanisms of low temperature (LT) signal transduction and cold acclimation. Mutant studies and microarray analyses have revealed C-Repeat binding factor (CBF) -dependent and -independent signaling pathways in plants. Experimental evidence suggests the existence of ‘potential LT sensors’ but as yet there is (...) no direct proof. A number of signal transducers such as various kinases/phosphatases have been demonstrated but the signal transduction pathways have not been elucidated. An understanding of the molecular basis of the signaling process, however, is of potential practical application. Designing new strategies to improve cold tolerance in crop varieties could increase the plant productivity and also expand the area under cultivation. BioEssays 27:1048–1059, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

This paper advances the development of a phylogeny-based psychology in which cognitive ability types are individuated as characters in the evolutionary biological sense. I explain the character concept and its utility in addressing (or dissolving) conceptual problems arising from discoveries of cognitive abilities across a wide range of species. I use the examples of stereopsis in the praying mantis, internal cell-to-cell signaling in plants, and episodic memory in scrub jays to show how anthropocentric cognitive ability types can be reformulated (...) into cognitive characters, thereby promoting the integration of psychology with other sciences of evolved traits. (shrink)

NIK1 is a receptor‐like kinase involved in plant antiviral immunity. Although NIK1 is structurally similar to the plant immune factor BAK1, which is a key regulator in plant immunity to bacterial pathogens, the NIK1‐mediated defenses do not resemble BAK1 signaling cascades. The underlying mechanism for NIK1 antiviral immunity has recently been uncovered. NIK1 activation mediates the translocation of RPL10 to the nucleus, where it interacts with LIMYB to fully down‐regulate translational machinery genes, resulting in translation inhibition (...) of host and viral mRNAs and enhanced tolerance to begomovirus. Therefore, the NIK1 antiviral immunity response culminates in global translation suppression, which represents a new paradigm for plant antiviral defenses. Interestingly, transcriptomic analyses in nik1 mutant suggest that NIK1 may suppress antibacterial immune responses, indicating a possible opposite effect of NIK1 in bacterial and viral infections. (shrink)

The defense of plants against herbivores and pathogens involves the participation of an enormous range of different metabolites, some of which act directly as defensive weapons against enemies (toxins or deterrents) and some of which act as components of the complex internal signaling network that insures that defense is timed to enemy attack. Recent work reveals a surprising trend: The same compounds may act as both weapons and signals of defense. For example, two groups of well‐studied defensive weapons, glucosinolates (...) and benzoxazinoids, trigger the accumulation of the protective polysaccharide callose as a barrier against aphids and pathogens. In the other direction, several hormones acting in defense signaling (and their precursors and products) exhibit activity as weapons against pathogens. Knowing which compounds are defensive weapons, which are defensive signals and which are both is vital for understanding the functioning of plant defense systems. (shrink)

Reactive oxygen species (ROS) are known as toxic metabolic products in plants and other aerobic organisms. An elaborate and highly redundant plant ROS network, composed of antioxidant enzymes, antioxidants and ROS-producing enzymes, is responsible for maintaining ROS levels under tight control. This allows ROS to serve as signaling molecules that coordinate an astonishing range of diverse plant processes. The specificity of the biological response to ROS depends on the chemical identity of ROS, intensity of the signal, sites (...) of production, plant developmental stage, previous stresses encountered and interactions with other signaling molecules such as nitric oxide, lipid messengers and plant hormones. Although many components of the ROS signaling network have recently been identified, the challenge remains to understand how ROS-derived signals are integrated to eventually regulate such biological processes as plant growth, development, stress adaptation and programmed cell death. (shrink)

Polarity is an inherent feature of almost all prokaryotic and eukaryotic cells. In most eukaryotic cells, growth polarity is due to the assembly of actin‐based growing domains at particular locations on the cell periphery. A contrasting scenario is that growth polarity results from the establishment of non‐growing domains, which are actively maintained at opposite end‐poles of the cell. This latter mode of growth is common in rod‐shaped bacteria and, surprisingly, also in the majority of plant cells, which elongate along (...) the apical–basal axes of plant organs. The available data indicate that the non‐growing end‐pole domains of plant cells are sites of intense endocytosis and recycling. These actin‐enriched end‐poles serve also as signaling platforms, allowing bidirectional exchange of diverse signals along the supracellular domains of longitudinal cell files. It is proposed that these actively remodeled end‐poles of elongating plant cells remotely resemble neuronal synapses. BioEssays 25:569–576, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

The biochemical mechanism by which the phytochrome family of plant sensory photoreceptors transmit perceived informational light signals downstream to transduction pathway components is undetermined. The recent sequencing of the entire genome of the cyanobacterium Synechocystis, however, has revealed a protein that has an NH2‐terminal domain with striking sequence similarity to the photosensory NH2‐terminal domain of the phytochromes, and a COOH‐terminal domain strongly related to the transmitter histidine kinase module of bacterial two‐component sensors. The Synechocystis protein is capable of autocatalytic (...) chromophore ligation and exhibits photoreversible light‐absorption changes analogous to the phytochromes, indicating its capacity to function as an informational photoreceptor. Together with earlier observations that the COOH‐terminal domains of the plant phytochromes also have sequence similarity to the histidine kinases, these data suggest that the cyanobacteria utilize photoregulated histidine kinases as a sensory system and that the plant phytochromes may be evolutionary descendants of these photoreceptors. (shrink)

The study of plant signaling and behaviour, whose aim is to address the physiological basis for adaptive behaviour in plants, is a growing and thought-provoking field of research. In this review we discuss relevant studies that try to interpret in a neurocognitive fashion cases in which plants seem to behave similarly to animals. By comparing observations and experiments about plants and animals, we propose a framework composed of three axes in which interactions of living organisms with the world (...) can be represented. The first axis refers to adaptiveness, the second to sensitivity, and the third to sentience. This model allows us to interpret the behaviours of living organisms along a continuum capable of giving a smooth transition from simple to complex responses. In light of this, plants show an excellent adaptiveness, a variable level of sensitivity, and a good degree of sentience (restricted to the immediate perception that something is happening to themselves). Only the organisms with a high degree of sentience can have the basis for developing consciousness. However, even though it is necessary for consciousness, sentience is not sufficient, as it must be associated with a complex functional organization of structures that can support a recursive and synchronized processing of information. So far, plants have been found to completely lack this type of organization. Plants appear to be, therefore, sentient but not conscious. (shrink)

Tumor suppressor genes represent a broad class of genes that normally function in the negative regulation of cell proliferation. Loss‐of‐function mutations in these genes lead to unrestrained cell proliferation and tumor formation. A fundamental understanding of how tumor suppressor genes regulate cell proliferation and differentiation should reveal important aspects of signalling pathways and cell cycle control. A recent report describing the Drosophila tumor suppressor gene warts has implications in the study of the human myotonic dystrophy gene(1). These genes encode members (...) of a cyclic AMP‐dependent protein kinase subfamily that includes other plant and animal orthologues. (shrink)

Summary A famous debate between John Ray, Joseph Pitton de Tournefort and Augustus Quirinus Rivinus at the end of the seventeenth century has often been referred to as signalling the beginning of a rift between classificatory methods relying on logical division and classificatory methods relying on empirical grouping. Interestingly, a couple of decades later, Linnaeus showed very little excitement in reviewing this debate, and this although he was the first to introduce the terminological distinction of artificial vs. natural methods. In (...) this paper, I will explain Linnaeus's indifference by the fact that earlier debates were revolving around problems of plant diagnosis rather than classification. From Linnaeus's perspective, they were therefore concerned with what he called artificial methods alone ? diagnostic tools, that is, which were artificial no matter which characters were taken into account. The natural method Linnaeus proposed, on the other hand, was not about diagnosis, but about relations of equivalence which played a vital, although largely implicit role in the practices of specimen exchange on which naturalists relied to acquire knowledge of the natural world. (shrink)

Back‐to‐back papers have described the identification of a family of receptors for the plant hormone auxin.(1, 2) Most developmental processes in plants are dependent on auxin signalling making this discovery a landmark in the search for the mechanism of auxin action. The TIR1 gene translates into a protein with recognised motifs including an F‐box domain and TIR1 forms part of an important ubiquitination complex that tags other proteins for degradation.(3) Specific amongst the targets of TIR1 are a set of (...) auxin‐regulated transcription factors.(4) The latest work has shown that TIR1 itself is also the binding site for auxin making it an auxin receptor with no requirement for a biochemical signalling cascade. BioEssays 27:1213–1217, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

A central goal of philosophy of perception is to uncover the nature of sensory capacities. Ideally, we would like an account that specifies what conditions need to be met in order for an organism to count as having the capacity to sense or perceive its environment. And on the assumption that sensory states are the kinds of things that can be accurate or inaccurate, a further goal of philosophy of perception is to identify the accuracy conditions for sensory states. In (...) this paper I recommend a novel approach to these core issues, one that draws heavily on game-theoretic treatments of signaling in nature. A benefit of the approach is that it helps us to understand why biologists attribute sensory powers to such a diverse range of organisms, including plants, fungi, and algae. (shrink)

Insect and pathogen attacks activate plant defense genes within minutes in nearby cells, and within hours in leaves far distant from the sites of the predator attacks. A search for signal molecules involved in both the localized and distal signalling has resulted in the identification of an 18‐amino‐acid polypeptide, called systemin, that activates defense genes in leaves of tomato plants when supplied at levels as low as fmols/plant. Several lines of evidence support a role for systemin as a (...) wound hormone. As with animal polypeptide hormones, systemin is derived from a larger precursor protein, called prosystemin, by limited proteolysis. Systemin has been shown by autoradiography to be phloemmobile and, by antisense technology, to be an essential component of the wound‐inducible, systemic signal transduction system leading to the transcriptional activation of the defensive genes. A search for the receptor of systemin has led to the identification in plant plasma membranes of a systeminbinding protein. However, this protein has properties not of a receptor, but of a furin‐like proteinase that cleaves systemin into smaller polypeptides. Systemin and its precursor prosystemin provide prototypes for the emerging possibilities that polypeptide hormones may have broad roles in signalling environmental stress responses, and in regulating plant growth and development as well. (shrink)

In plants, successful sexual reproduction and the ensuing development of seeds and fruits depend on flowering at the right time. This involves coordinating flowering with the appropriate season and with the developmental history of the plant. Genetic and molecular analysis in the small cruciform weed, Arabidopsis, has revealed distinct but linked pathways that are responsible for detecting the major seasonal cues of day length and cold temperature, as well as other local environmental and internal signals. The balance of signals (...) from these pathways is integrated by a common set of genes to determine when flowering occurs. Excitingly, it has been discovered that many of these same genes regulate flowering in other plants, such as rice. This review focuses on recent advances in how three of the signalling pathways (the day‐length, vernalisation and autonomous pathways) function to control flowering. BioEssays 26:363–373, 2004. © 2004 Wiley‐Liss, Inc. (shrink)

On receiver-based teleosemantic theories of representation, the chemical states of the circadian clocks in animal, plant and cyanobacterial cells constitute signals of future states of affairs, often the rising and setting of the sun. This signalling is much more rigid than sophisticated representational systems like human language, but it is not simple on all dimensions. In most organisms the clock regulates many different circadian rhythms. The process of entrainment ensures that the mapping between chemical states of the clock and (...) the daily light-dark cycle is adjusted to deal with seasonal changes. In regulating anticipatory behaviour, the states of the clock look forward both to the time the behaviour is supposed to happen and the later time when the anticipated circumstances are supposed to arise. The case of the circadian clock shows that purely indicative signals can arise in very basic biological systems and brings into sharp relief the trade-offs involved in characterizing representational systems. On receiver-based teleosemantic theories, future-directed signals are not restricted to complex multicellular organisms but are ubiquitous in the biological world. (shrink)

Recently, we found that the Pseudomonas aeruginosa type II secreted protease IV functions as a unique Arabidopsis innate immunity elicitor. The protease IV‐activated pathway involves G protein signaling and raises the question of how protease elicitation leads to the activation of G protein‐mediated signaling, because plants do not appear to have metazoan‐like G protein‐coupled receptors. Importantly, our data suggest that Arabidopsis has evolved a mechanism to detect the proteolytic activity of a pathogen‐encoded protease, supporting the host‐pathogen arms race (...) model. In the case of opportunistic multi‐host pathogens like P. aeruginosa, however, it is not plausible that P. aeruginosa is simultaneously co‐evolving in a gene‐for‐gene manner with all of its potential hosts, which include plants, nematodes, insects, and mammals. This prompts us to ask what is the driving force for co‐evolution of defense response in Arabidopsis and pathogenesis of P. aeruginosa, which might not have been subject to iterative cycles of evolutionary selections. (shrink)

Genes induced by the plant hormone auxin are probably involved in the execution of vital cellular functions and developmental processes. Experimental approaches designed to elucidate the molecular mechanisms of auxin action have focused on auxin perception, genetic dissection of the signaling apparatus and specific gene activation. Auxin‐responsive promoter elements of early genes provide molecular tools for probing auxin signaling in reverse. Functional analysis of several auxin‐specific promoters of unrelated early genes suggests combinatorial utilization of both conserved and (...) variable elements. These elements are arranged into autonomous domains and the combination of such modules generates uniquely composed promoters. Modular promoters allow for auxin‐mediated transcriptional responses to be revealed in a tissue‐ and development‐specific manner. (shrink)

Organisms actively compete for environmental resources. They assess their surroundings, estimate how much energy they need for particular goals, and then realize the optimum variant. They take measures to control certain environmental resources. They perceive themselves and can distinguish between “self” and “non-self.” Current empirical data on all domains of life indicate that unicellular organisms such as bacteria, archaea, giant viruses, and protozoa as well as multicellular organisms such as animals, fungi, and plants coordinate and organize their essential life functions (...) through signaling processes. Signaling allows for real life coordination and organization and is a communicative action in which speciesspecific behavioral patterns and sign repertoires are used. Cells, tissues, organs, and organisms that communicate share several key levels that are essential to all life forms and which serve as a uniform tool for investigating biocommunication. (shrink)

Forty years’ experience as a bacterial geneticist has taught me that bacteria possess many cognitive, computational and evolutionary capabilities unimaginable in the first six decades of the twentieth century. Analysis of cellular processes such as metabolism, regulation of protein synthesis, and DNA repair established that bacteria continually monitor their external and internal environments and compute functional outputs based on information provided by their sensory apparatus. Studies of genetic recombination, lysogeny, antibiotic resistance and my own work on transposable elements revealed multiple (...) widespread bacterial systems for mobilizing and engineering DNA molecules. Examination of colony development and organization led me to appreciate how extensive multicellular collaboration is among the majority of bacterial species. Contemporary research in many laboratories on cell–cell signaling, symbiosis and pathogenesis show that bacteria utilise sophisticated mechanisms for intercellular communication and even have the ability to commandeer the basic cell biology of ‘higher’ plants and animals to meet their own needs. This remarkable series of observations requires us to revise basic ideas about biological information processing and recognise that even the smallest cells are sentient beings. Previous article in issue. (shrink)

Forty years’ experience as a bacterial geneticist has taught me that bacteria possess many cognitive, computational and evolutionary capabilities unimaginable in the first six decades of the twentieth century. Analysis of cellular processes such as metabolism, regulation of protein synthesis, and DNA repair established that bacteria continually monitor their external and internal environments and compute functional outputs based on information provided by their sensory apparatus. Studies of genetic recombination, lysogeny, antibiotic resistance and my own work on transposable elements revealed multiple (...) widespread bacterial systems for mobilizing and engineering DNA molecules. Examination of colony development and organization led me to appreciate how extensive multicellular collaboration is among the majority of bacterial species. Contemporary research in many laboratories on cell–cell signaling, symbiosis and pathogenesis show that bacteria utilise sophisticated mechanisms for intercellular communication and even have the ability to commandeer the basic cell biology of ‘higher’ plants and animals to meet their own needs. This remarkable series of observations requires us to revise basic ideas about biological information processing and recognise that even the smallest cells are sentient beings. (shrink)

Food labels serve important informational and signaling purposes however, the subjective beliefs associated with ethical labels such as farm animal welfare labels and their influence on anti-consumption behavior are not well-understood. This paper aims to address how subjective beliefs about FAW labels affect the milk anti-consumption behavior for different segments of consumers. Data from an in-person opt-in survey conducted in the US were used to address the objectives of this study. Information on respondents’ sociodemographic profile, milk choice and perceptions (...) about FAW was collected. Data were analyzed using multivariate regressions. The results show that FAW labels served as heuristic cues for higher environmental quality and health. The presence of labels also evoked a positive feeling in consumers. The FAW halos impacted milk anti-consumption. The effects however depended on preference type—milk versus plant-based alternative milk beverages. The results highlight the possibility of appealing to the relevant FAW subjective beliefs by stakeholders interested in fostering anti-consumption behavior as a means to achieving more sustainable consumption behavior. (shrink)

Heterotrimeric G proteins, consisting of α, β, and γ subunits, couple ligand-bound seven transmembrane domain receptors to the regulation of effector proteins and production of intracellular second messengers. G protein signaling mediates the perception of environmental cues in all higher eukaryotic organisms, including yeast, Dictyostelium, plants, and animals. The nematode Caenorhabditis elegans is the first animal to have complete descriptions of its cellular anatomy, cell lineage, neuronal wiring diagram, and genomic sequence. In a recent paper, Jansen et al.(1) used (...) sequence searches of the C. elegans genome database to identify all heterotrimeric G protein genes (20 Gα, 2 Gβ, 2 Gγ). C. elegans encodes one ortholog of each of the four Gα classes found in metazoans and 16 new Gα genes. The orthologous genes are widely expressed, whereas 14 of the divergent Gα genes are almost exclusively expressed in sensory neurons where they may regulate perception and chemotaxis.BioEssays 21:713–717, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Food turns out to be not only the nutrient supplier for our body but also a carrier of regulatory information. Interestingly, a recent study made the discovery that some plant/food‐derived microRNAs (miRNAs) accumulate in the serum of humans or plant‐feeding animals, and regulate mammalian gene expression in a sequence‐specific manner. The authors provided striking evidence that miRNAs could function as active signaling molecules to transport information across distinct species or even kingdoms. Although the mechanism of how miRNAs (...) are shuttled between different organisms is still not well characterized, initial results point to the involvement of microvesicles and specific RNA‐transporter‐like proteins. These findings raise both speculation about the potential impact that plants may have on animal physiology at the molecular level, and an appealing possibility that food‐derived miRNAs may offer us another means to deliver necessary nutrients or therapeutics to our bodies. (shrink)

Via a historical reconstruction, this paper primarily demonstrates how the societal debate on genetically modified organisms (GMOs) gradually extended in terms of actors involved and concerns reflected. It is argued that the implementation of recombinant DNA technology out of the laboratory and into civil society entailed a “complex of concerns.” In this complex, distinctions between environmental, agricultural, socio-economic, and ethical issues proved to be blurred. This fueled the confusion between the wider debate on genetic modification and the risk assessment of (...) transgenic crops in the European Union. In this paper, the lasting skeptical and/or ambivalent attitude of Europeans towards agro-food biotechnology is interpreted as signaling an ongoing social request – and even a quest – for an evaluation of biotechnology with Sense and Sensibility. In this (re)quest, a broader-than-scientific dimension is sought for that allows addressing the GMO debate in a more “sensible” way, whilst making “sense” of the different stances taken in it. Here, the restyling of the European regulatory frame on transgenic agro-food products and of science communication models are discussed and taken to be indicative of the (re)quest to move from a merely scientific evaluation and risk-based policy towards a socially more robust evaluation that takes the “non-scientific” concerns at stake in the GMO debate seriously. (shrink)

In the late nineteenth century, Jagadish Chandra Bose devised millimeter- and micro-wave experiments to record responses of plants to electromagnetic stimuli. Based on these experiments, Bose conceptualized his thesis of the unity of living and nonliving entities through their different sensitivities to electromagnetic vibrations. By relating Bose’s thesis of the unity of life based on electromagnetic vibrations to Alfred North Whitehead’s process philosophy and N. Katherine Hayles’s work on the cognitive nonconscious, I argue for a processual media theory that connects (...) both human and plant intelligence to electromagnetic signaling. In doing so, I examine how discourses about different living bodies (plants, animals, humans) variously sensing their environments are formulated into claims about which species have what degree of cognitive capability and intelligence. I trace the influence of Bose’s work on the ecological thinking of the 1970s espoused by cyberneticists and countercultural environmentalists and on contemporary plant neurobiologists who are closely working with Internet of Things designers and researchers. This enables me to emerge with an understanding of electrosensitivity that acknowledges that there is more to the intensities and energies of signals than mere data and that such infra-informatic signals can create both capacities and incapacities, capabilities and debilities, in bodies. (shrink)