Boyd R. Strain, Ph.D. - US grants

The Phytotron at Duke University is a large integrated facility for biological research under controlled environments. Central mechanical and environmental monitoring equipment operated by a trained professional staff provides excellent and dependable environmental control. The facility is available to all scientists who require well-controlled environmental conditions for their experiments. Future developments planned for the facility are to install new lighting and control systems to improve the quality of environmental control and the dependability of equipment. A new computerized monitoring system will provide more environmental sensing and more frequent updating of chamber conditions. Energy conservation measures initiated by the staff and by the Duke University Energy Management Section will be continued. Efforts will be continued to develop unique analytical capabilities. In addition to the high-energy carbon-11 analytical facility now in operation, a mass spectrometer facility will be installed by Duke. Existing storage space will be renovated by the University into modern physiological research laboratories to support a growing program in ecological research. This project will provide funds for the continued basic operation of this national environmental control facility. NSF funds will be supplemented by space charges to users and by an operational budget from Duke University.

ABSTRACT Duke University requests $700,000 to enhance capabilities of the National Phytotron by the addition of 18 new controlled environment (CE) chambers. The Phytotron, an NSF-funded national research facility established in 1968, consists of 40 artificially lighted CE growth chambers and 6 glasshouses that provide more that 477 m2 of controlled environmental space for advanced research in environmental plant biology. These CE units are used to reproduce different types of environments -- ranging from the arctic to the desert to the tropics. This allows researchers to have precise control over environmental conditions, e.g., air temperature, irradiance, carbon dioxide, relative humidity, and nutrient concentration, thereby providing an opportunity to gain increased understanding of the complex interactions between plants and their environment, which is virtually impossible to do under natural, uncontrolled field conditions. The Phytotron hosts, on yearly average, 17 students, 4 postdoctoral scientists, and 20 senior scientists, 73% of whom are off - campus users. The Phytotron's current CE growth chambers have operated continuously for 25 years. While some have been upgraded, their limited analog controls are not adequate for precise and flexible control of multiple environments variables, e.g., temperature, light, and humidity. In addition, these older chambers lack sophisticated computer-based monitoring capabilities, thus limiting researchers' abilities to monitor experiments and to reproduce short-term, variable environmental conditions, which are critical to understanding processes like carbon allocation, photosynthesis, and acclimation. Over the past decade, the environmental factors that researchers have most frequently manipulated in the Phytotron are the effects of carbon dioxide and temperature -- other factors include drought stress, nutrient availability, photoperiod, UV-B radiation, and salinity. With Excelle nt lighting, digital controls, and real time monitoring, the 18 new controlled environment chambers will provide the flexible, quality-controlled environment needed by a range of projects, including molecular, whole-plant (including such as areas as leaf physiology and growth dynamics), biotic interactions (e.g., plant-plant and plant-animal interactions and pathogens), population genetics, and ecosystem microcosms. Acquisition of these 18 state-of-the-art chambers will have an immediate and substantial impact on U.S. ecological research, particularly studies on the effects of global change on plants and ecosystems, efforts to scale processes across biological levels of organization, and basic molecular and physiological studies of carbon fixation, allocation, and respiration. This instrumentation will build upon and enhance NSF's investment in ecological research and allow the National Phytotron to address national needs in the biological sciences, including graduate and postgraduate education, and to remain one of the most important centers for controlled environment research in ecology in the United States.

9520752 Atmospheric carbon dioxide is expected to double within the next 80 years due to burning of fossil fuels and deforestation of tropical rainforests. Analyses of ancient air trapped within ice have shown that atmospheric carbon dioxide may have been as low as 50% of the current level approximately 20,000 years ago. We know that many plants increase growth and reproduction when grown under high carbon dioxide and decrease growth and reproduction when grown under low carbon dioxide. We know very little, however, about the evolutionary responses of plants to changing levels of carbon dioxide. That information is needed to: a) accurately predict plant responses under future scenarios of high carbon dioxide, b) understand how plants survived during low carbon dioxide levels of the past and c) determine the processes by which plants evolve in response to changing levels of carbon dioxide. This research will use the annual plant Arabidopsis thaliana as a model system to study the evolutionary responses of plants under low and high carbon dioxide. It will determine whether individual plants show variation in growth and reproduction under low and high carbon dioxide and examine the response of populations to selection for increased reproduction under low and high carbon dioxide. It will test to see whether such selection produces plants with an adaptive advantage and determine what physiological and developmental processes are associated with evolution of plants in response to carbon dioxide. This research will increase our understanding of the processes by which plants adapt to changing carbon dioxide levels over geologic time, and improve our ability to predict and understand the changes that plants may undergo due to human-caused changes in atmospheric carbon dioxide levels.

Duke University requests funds to enhance the National Phytotron. To obtain fundamental understanding and to develop predictive models of the processes that mediate plant activities and exchanges requires access to sophisticated controlled environment conditions. The Phytotron, an NSF-supported national research facility established in 1968, consists of 40 artificially lighted CE growth chambers and 6 glasshouses that provide more than 477 M2 of controlled environmental space for advanced research in environmental plant biology. The Phytotron hosts students, postdoctoral scientists, and senior scientists, most of whom are off - campus users. The CE units are used to reproduce different types of environments -- ranging from the arctic to the desert to the tropics. This allows researchers to have precise control over environmental conditions, e.g., air temperature, irradiance, carbon dioxide, relative humidity, and nutrient concentration, thereby allowing for research on the complex interactions between plants and their environment, which is virtually impossible to do under natur al uncontrolled field conditions. This proposal would provide for new monitoring equipment for the CE units, new growth chambers to meet newer demands for environmental controls, upgraded glasshouse materials and control units, and salaries for technical and oversight needs. The continued support of the National Phytotron enhances NSF s investment in ecological research, including graduate and postgraduate education, and will allow the National Phytotron to remain one of the most important centers for controlled environment research in ecology in the United States.