Physiological and Structural Systems (PSS)

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Important Information for Proposers

A revised version of the NSF Proposal & Award Policies & Procedures Guide (PAPPG) (NSF 22-1), is effective for proposals submitted, or due, on or after October 4, 2021. Please be advised that, depending on the specified due date, the guidelines contained in NSF 22-1 may apply to proposals submitted in response to this funding opportunity.

Supports research on whole-organism physiology and functional morphology, including mechanisms underlying interactions among viruses, prokaryotes and eukaryotes; organismal structural features; and organismal responses to abiotic/biotic environments.


Solicitation  21-506

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 research encompassing a wide range of approaches and perspectives.  Although research supported by the PSS Cluster includes molecular approaches and the interface of organismal biology with population biology, the intellectual focus of this research is on understanding whole organisms.  The Cluster encourages submission of proposals aimed at 1) identifying fundamental design principles of physiological and structural systems; 2) understanding 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 at the interfaces of biology, physics, chemistry, mathematics, computer science and engineering is also encouraged.  The PSS Cluster will not consider projects that are primarily focused on environmental toxicology or endocrine disrupting chemicals.  Projects that are entirely focused at the cellular and/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, Joanna Shisler, (703) 292-5368,; Mamta Rawat, (703) 292-7265, supports research on processes and mechanisms mediating antagonistic or beneficial interactions within and between viruses, prokaryotes, and eukaryotes with the exception of plants.  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., predatory wasps laying eggs in a caterpillar).  The program welcomes proposals on the initiation, transmission, maintenance and dissolution of these complex associations.  Also of interest are studies of 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 Physiological Mechanisms and Biomechanics Program (PMB) (Program Code 7658, Kathryn Dickson, (703) 292-7380,; Nicole Donofrio, (703) 292-2196,; Aruna Kilaru, (703) 292-7481, supports research on the physiological mechanisms and structural features of organisms.  Broad thematic areas include 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 or use systems or modeling approaches to predict physiological or biomechanical principles of organismal function 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, Irwin Forseth, (703) 292-7862,; Theodore Morgan, (703)  292-7868,;  Sean Place, (703) 292-7338, 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.  Projects focused on understanding how processes integratively result in the capacities of organisms to live in dynamic and stressful environments, and those focused on using traits to build or improve predictive models of organismal responses to environmental changes, are encouraged.  Projects focused exclusively on cellular or subcellular processes without integration at the whole organism level of analysis are not appropriate for this program. 

The NSF-NIFA Plant Biotic Interactions Program (PBI) (Program Code: 047Y, Michael Mishkind, (703) 292-7190,; John McDowell, (703) 292-8008, 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 focused exclusively on population level and ecological processes are not appropriate for this program.  Important Note:  PBI is jointly managed by the NSF and USDA-NIFA.  Proposals should be submitted to NSF 20-576.  See the PBI web page for the program summary and a link to the solicitation.  (

Program contacts

Kathryn Dickson (703) 292-7380 BIO/IOS
Nicole Donofrio (703) 292-2916 BIO/IOS
Irwin Forseth (703) 292-7862 BIO/IOS
Aruna Kilaru
Program Director (703) 292-7481 BIO/IOS
Michael Mishkind (703) 292-7190 BIO/IOS
John McDowell (703) 292-8008 BIO/IOS
Theodore Morgan (703) 292-7868 BIO/IOS
Sean Place (703) 292-7338 BIO/IOS
Mamta Rawat (703) 292-7265 BIO/IOS
Joanna Shisler (703) 292-5368 BIO/IOS

Awards made through this program

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