John Cushman: Improving cactus pear productivity for bioenergy production under hot and arid conditions

Title

Improving cactus pear productivity for bioenergy production under hot and arid conditions

Mentor

Department

Biochemistry, Molecular Biology, and Biotechnology

Biosketch

John C. Cushman is a foundation professor at the University of Nevada, Reno and director of the Biochemistry Graduate Program in the Department of Biochemistry & Molecular Biology. He earned a B.S. degree in biology from Ursinus College, and his M.S. and Ph.D. degrees in microbiology from Rutgers University. He was awarded a National Science Foundation (NSF) postdoctoral fellowship in plant biology and conducted postdoctoral research at the University of Arizona on the induction of Crassulacean Acid Metabolism (CAM) by environmental stress under. Professor Cushman’s research is focused on plant responses to abiotic stress with an emphasis on cold, salinity, drought responses and mechanisms of desiccation tolerance. More recently, his laboratory has used engineered tissue succulence and crassulacean acid metabolism (CAM) to improve the water-use efficiency, salinity, and water-deficit stress tolerance in model plant species with the long-term goal of moving these water-conserving adaptations into food, feed, and (bio)fuel crops enabling production on marginal or abandoned agricultural lands. His laboratory is also investigating the productivity and irrigation response of highly productive CAM crops such as cactus pear (Opuntia spp.) to serve as food and feed sources and as a biofuel feedstock for semi-arid and arid regions of the world.

Project overview

Cactus pear serves as a dedicated bioenergy feedstock for producing methane, ethanol, and sustainable aviation fuel, as well as producing human food or animal feed and various bioproducts, which adds to its ecological and economic value. The overall goal of this project is to understand and improve the high biomass productivity of cactus pear (Opuntia spp.), establishing it as an excellent bioenergy feedstock for sustainable biomass production under hot and arid conditions that are often associated with abandoned or marginal lands. To achieve this goal, three aims will be pursued: 1) Investigate the genetic basis for the high water-use efficiency (WUE) and nitrogen-use efficiency (NUE) of Opuntia spp. using the national germplasm collection of spineless Opuntia spp. accessions, 2) Survey and characterize the microbiomes associated with Opuntia spp. to optimize sustainable biomass production with minimal inputs, and 3) Conduct integrative and predictive modeling of synthetic microbial communities that result in optimal biomass production and carbon sequestration from plant-microbe-soil systems. The Pack Research Experience Program (PREP) student will be trained on DNA isolation from rhizosphere, rhizoplane, and phytosphere to identify and characterize beneficial microorganisms for metagenomic sequencing. The student will also learn how to characterize the degree of CAM engagement within cactus pear populations using titratable acidity, malate content, and delta 13C isotopic profiling. The student will also be trained on the characterization of microbial nutritional requirements using a high-throughput phenotyping system.

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