John Cushman

Professor and Director, Biochemistry (BCH) Graduate Program
john cushman

Summary

Research interests

  • Functional Genomics of Crassulacean acid metabolism (CAM): CAM is a 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).
  • Opuntia ficus-indica: A Highly Water-Use Efficient And Productive Biomass Feedstock For Semi-Arid Lands: The goal of this research is to expand the use of cactus pear (Opuntia ficus-indica) as highly water-use efficient, highly productive, and climate-resilient biomass feedstock for semi-arid regions of the U.S. The major research goals are to 1) develop molecular identifiers from complete chloroplast genome sequence information for resolving the genetic structure of the germplasm collection of O. ficus-indica to remove genetically identical accessions and resolved species designations; 2) evaluate available public germplasm collection of O. ficus-indica for biomass productivity under standard irrigation and fertilization conditions in the field; 3) evaluate elite germplasm for optimal water and fertilization inputs, refine productivity models, and perform life-cycle assessment (LCA) and life-cycle costing (LCC) analyses; 4) develop effective strategies to overcome barriers to production including overcoming Opuntia stunting disease (OSD) and supporting effective insect management programs for insect pests.  An innovative extension program will inform interested stakeholders about the benefits of cactus pear production systems in arid and semi-arid regions and disseminate research results through public outreach and education.     
  • Genetic improvement and field testing of Tef: A forage, fodder, and highly nutritious, gluten-free grain crop for dryland agriculture: Tef (Eragrostis tef (Zucc.) Trotter, Poaceae) is a warm season, C4-photosynthesis grass that is gaining popularity in the U.S. as a high-quality forage, fodder, and highly nutritious, gluten-free grain. Tef productivity is limited by susceptibility to lodging due to its characteristic tall and weak stems, low seed production per unit area (or productivity), and small seed size. The long-term goals of the proposed integrated research and extension project are to accelerate E. tef domestication to suit U.S. agriculture needs through improving existing genomic resources, evaluating the agronomic performance of highly productive and drought tolerance accessions, and improving lodging resistance and overall grain yield.
  • Engineering CAM Photosynthetic Machinery into Food and Bioenergy Crops in Marginal Environments: Future increases in drought severity and duration will significantly slow the rate of crop productivity increases needed to satisfy future projected crop demands and threaten global food security. Therefore, innovative synthetic biology approaches for curtailing photorespiration and improving water-use efficiency via the introduction of synthetic crassulacean acid metabolism (CAM) into C3 photosynthesis crops are essential. The goal of this project is to test optimized synthetic versions of CAM alone and in combination with engineered tissue succulence. The proposed synthetic gene circuits can be applied widely to other food, feed, fiber, and biofuel crops to improve their productivity, reduce photorespiration, improve water-use efficiency, and drought/salinity stress tolerance under the hotter and drier environments of the future.

Our research is funded by the National Science Foundation (NSF), the United States Department of Agriculture (USDA) National Institutes of Food and Agriculture, 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.

Courses

  • BCH 703 - Grant Writing for Molecular Biosciences
  • BCH 705 - Molecular Genetics
  • BCH 706 - Functional Genomics
  • BCH 718 - Plant Molecular Biology and Biotechnology
  • BCH 794 - Plant Biochemistry Colloquium
  • Biochemistry Graduate Program Director

Honors and awards

  • 2017 Regents' Researcher Award
  • 2013 Outstanding UNR Researcher Award
  • 2011-2013 Foundation Professor
  • 2003 Outstanding CABNR Researcher Award

Service

Editor, The Plant Journal; Associate Editor, Journal of the Professional Association for Cactus Development; Guest editor, Journal of Experimental Botany; Handling Editor, Journal of Plant Physiology

Education

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