John Cushman

john cushman

John Cushman

Professor & Graduate Student Director

Summary

  • Functional Genomics of Crassulacean acid metabolism (CAM): CAM is water-conserving photosynthetic pathway that helps plants survive in seasonally arid climates or those with intermittent water supply (e.g. epiphytic habitats). Our research objectives are to understand how the expression of CAM is controlled by environmental stress (salinity, water deficit) and the circadian clock. Our approach is to conduct integrated transcriptome, proteome, and metabolome analyses using a model facultative CAM species called the common or crystalline ice plant (Mesembryanthemum crystallinum).

 

  • Evolutionary Origins of Crassulacean acid metabolism in Neotropical Orchids: Crassulacean acid metabolism (CAM) has evolved multiple times in 33 families and 328 genera comprising more than 6% of all vascular plant species making it the second most common mode of photosynthesis among vascular plants. Our goal is to understand the molecular mechanisms responsible for the evolution of this important photosynthetic adaptation. Our approach is to survey foliar carbon isotopic composition (delta13C) to map the occurrence of CAM in closely related species within the Oncidiinae, a subtribe within Orchidaceae, and then identify molecular genetic changes specific to plants that exhibit CAM.

 

  • Gene Discovery in Resurrection Species: The long-term goal of this integrated research-education-extension project is to use resurrection plants as models to develop and enhance course offerings in Plant Breeding and Biotechnology and related topics, to develop an integrated research and extension project using Sporobolus as a forage grass, and to gain a basic understanding of the unique gene and gene regulatory networks that are necessary and sufficient for vegetative tissues to withstand dehydration and then rapidly recover upon rehydration that will serve as a case study for advanced teaching modules for crop improvement strategies.

 

  • Improved Abiotic Stress Tolerance in Camelina: The long-term goal of this research program is to improve the drought tolerance and other production traits of Camelina so that is might serve as a biofuel crop within the northern Nevada and the Great Basin. The goals are to test different varieties of Camelina to determine which might be suitable for regional growing conditions, develop improved traits such as heat, drought, and salinity tolerance, herbicide resistance, and shatter resistance of pods, using various genetic approaches, create a transcriptome database for all tissues under abiotic stress conditions, and provide educational outreach to inform stakeholders about the utility of Camelina as a regional biodiesel feedstock.

 

  • Development of Opuntia (Prickly Pear Cactus) as a Low-water-input Oleogenic Biofuel and Biomass Feedstock: The long-term goals of this research program are to enhance existing transcriptome resources for Opuntia ficus-indica, generate oleogenic cactus that accumulates lipids within vegetative and fruit tissues, evaluate such cactus for increased accumulation of lipids and other feedstock characteristics, and provide educational outreach to inform stakeholders using an educational display on biofuels production.

 

  • Engineering CAM Photosynthetic Machinery into Bioenergy Crops for Biofuels Production in Marginal Environments: The long-term goal of this research program is to enhance water use efficiency (WUE) and adaptability to hotter/drier climates of C3 species by introducing Crassulacean acid metabolism (CAM) thereby developing new capabilities for biomass production on marginal or abandoned agricultural lands while minimizing water and nitrogen inputs. The specific goals are to define the genetic basis of a set of CAM modules in eudicot and monocot species using network modeling data derived from 'omics data sets, characterize the regulation of carboxylation, decarboxylation, and stomatal control modules using comparative genomic, network/molecular dynamics modeling, and loss-of-function testing, deploy advanced genetic engineering technologies to enable stacking of large numbers of transgenes to improve transgene persistence, and to transfer fully functional CAM modules, and analyze the effects of different CAM modules on stomatal control, CO2 assimilation and transpiration rates, water use efficiency, and biomass yields in Arabidopsis and Poplar.

Our research is funded by the Department of Energy (DOE) and the Nevada Agricultural Experiment Station (NAES).

Students and postdoctoral research associates with broad interests in plant molecular genetics and plant biochemistry related to abiotic stress tolerance and bioenergy production systems are welcomed to pursue training opportunities in this laboratory.

Education

B.S. 1982 Ursinus College
M.S. 1984 Rutgers University - New Brunswick
Ph.D. 1986 Rutgers University - New Brunswick