Physiological and Structural Systems (PSS)

The Physiological and Structural Systems (PSS) Cluster supports research to advance understanding of whole-organism physiological mechanisms and functional morphology.  PSS supports hypothesis-driven, organismal-focused research encompassing a wide range of approaches and perspectives, spanning scales from molecular, genomic, and cellular levels to those interacting with population biology.  The Cluster encourages submission of proposals aimed at 1) identifying fundamental mechanistic principles of physiological and structural systems, 2) understanding how and why particular morphological and physiological mechanisms have evolved, and 3) how they are integrated at the level of the whole organism.  The Cluster welcomes projects involving modeling and theoretical approaches integrated with experimental approaches.  Multidisciplinary research that interfaces with biology, physics, chemistry, mathematics, computer science and engineering is also encouraged.  Projects that are entirely focused at the cellular, molecular, or biochemical level, without integration at the organismal level, are not appropriate for this cluster.

The Symbiosis, Infection and Immunity (SII) Program (Program Code: 7656, Mamta Rawat, (703) 292-7265, mrawat@nsf.gov; Joanna Shisler, (703) 292-5368, jshisler@nsf.gov; Carol Fassbinder-Orth, (703) 292-8064, cfassbin@nsf.gov) supports research on processes and mechanisms mediating antagonistic or beneficial interactions within and between viruses, prokaryotes, and eukaryotes; note that plant focused research in these areas is supported by the Plant Biotic Interactions program (see below).  These relationships can include cross-and within-kingdom interactions and may scale from the level of cellular (e.g., virus-cell interactions) to organismal (e.g., host-microbiome).  The program welcomes proposals on the initiation, transmission, maintenance and dissolution of these complex associations.  Also of interest are studies of host-microbiome interactions, immunity (scaling from molecules to cells to systems), mechanisms responsible for self/non-self recognition, and microbial manipulation of immune defenses.  Comparative approaches to identify immune defense mechanisms or microbial counter-measures are encouraged.  Integrative approaches and attention to emergent properties of symbiotic interactions are also encouraged, as are all aspects and types of symbiosis within and between non-plant organisms, including mechanisms of foreign organelle acquisition and maintenance.  The program's scope ranges from fundamental research to proof-of-concept experiments in which the results of fundamental research could be used for economic or societal impacts (e.g., developing diagnostics, prophylactics and therapeutics for non-human diseases).  

The Physiological Mechanisms and Biomechanics Program (PMB) (Program Code 7658, Kathryn Dickson, (703) 292-7380, kdickson@nsf.gov; Miriam Ashley-Ross, (703) 292-4997, mashleyr@nsf.gov; Nicole Donofrio, (703) 292-4639, ndonofri@nsf.gov) supports fundamental research that addresses mechanisms of physiological processes and biomechanics in the context of the whole organism, as well as studies of physiological plasticity and adaptation.  Broad thematic areas include homeostatic control and signaling mechanisms, solute transport, gas exchange, circulation, osmoregulation, metabolism, energetics, endocrinology, reproductive physiology, muscle physiology, biomechanics, biomaterials and functional morphology.  Projects that integrate across levels of biological organization, use modeling approaches to predict physiological or biomechanical principles of organismal function, and move beyond correlational results to test mechanistic hypotheses are encouraged.  Projects focused exclusively on cellular or subcellular processes without integration at the whole organism level are not appropriate for this program.

The Integrative Ecological Physiology Program (IEP) (Program Code: 7657, Theodore Morgan, (703) 292-7868, tmorgan@nsf.gov; Keith Reinhardt, (703) 292-4854, kreinhar@nsf.gov; Patrick Abbot, (703) 292-4740, dkabbot@nsf.gov; Irwin Forseth, (703) 292-8413, iforseth@nsf.gov) supports research on genetic, biochemical, morphological and physiological mechanisms underlying organismal responses to their abiotic and biotic environments.  The program seeks proposals framed in explicit ecological or evolutionary contexts that test integrative hypothesis aimed at understanding the mechanisms involved in how organisms evolve and respond to dynamic and/or stressful environments.  Proposals integrating an understanding of cause-and-effect relationships with theoretical or conceptual models of organismal responses to their environments and comparative studies across multiple organismal systems are encouraged.  Projects focused exclusively on cellular or subcellular processes without integration at the whole organism level or without ecological or evolutionary contexts are not appropriate for this program.  

The NSF-NIFA Plant Biotic Interactions Program (PBI) (Program Code: 047Y, Courtney Jahn, (703) 292-7746, cjahn@nsf.gov; Aardra Kachroo, (703) 292-7826, akachroo@nsf.gov) supports research on the processes that mediate beneficial and antagonistic interactions between plants and their viral, bacterial, oomycete, fungal, plant, and invertebrate symbionts, pathogens and pests, as well as pollen-pistil interactions and other examples of plant self/non-self recognition.  Research supported by the program spans molecular, genetic, biochemical, cellular, metabolic and whole organism perspectives.  Projects must be strongly justified in terms of fundamental biological processes and/or relevance to agriculture and may be purely fundamental or applied or include aspects of both perspectives.  Projects focused exclusively on population level and ecological processes are not supported for this program.  Important Note:  PBI is jointly managed by the NSF and USDA-NIFA.  See the PBI web page for the program summary and a link to the current solicitation: Plant Biotic Interactions | NSF - National Science Foundation.

For all IOS programs including those in the PSS Cluster, biological research on mechanisms of disease in humans, including on the etiology, diagnosis, or treatment of disease or disorder, is normally not supported.  Biological research to develop animal models of such conditions, or the development or testing of procedures for their treatment, also is not normally eligible for support. More information on NSF support of human diseases related research can be found in the Proposal & Award Policies & Procedures Guide (PAPPG).