Arnold J. Bloom

Arnold Bloom

Position Title
Distinguished Professor

  • Faculty
UC Davis, One Shields Ave, Davis CA 95616


  • Ph.D., Stanford University; Biological Sciences, 1979
  • B.A., Yale University; Physics, 1971

Research interests and expertise: 

My research has examined environmental stress tolerance in plants. This includes chilling injury and water stress in crops from tropical origins, plant responses to rising carbon dioxide in Earthís atmosphere, and nutrient deficiencies and toxicities. Currently, I focus on the interplay among plant acquisition of energy through photosynthesis and the acquisition of nutrients from the soil, particularly nitrogen and its diverse forms. I have discovered that most plants, contrary to popular belief, do not waste over 30 percent of their energy in a futile cycle called photorespiration. Rather, the photorespiratory pathway generates additional organic acids in the chloroplast that empower many energy-intensive chemical reactions such as those involved in nitrate assimilation. The balance between carbon fixation and photorespiration, thus, determines plant carbon/nitrogen balance and protein concentrations. Understanding the regulation of these processes is critical for sustaining food quality under rising CO2 atmospheres.

Current projects: 

  • NSF IOS-16-55810, Use of nitrate and ammonium at elevated CO2 in Arabidopsis, 2017-20, $780,869
  • USDA-IWYP-16-06702, Influence of N form on wheat protein yield, 2016-19, $993,060
  • NSF IOS-13-58675, Elevated CO2, nitrogen metabolism, and photorespiration, 2014-18, $218,899
  • UCOP ILTI, Expansion of online course about climate change, Head PI, 2014-18, $110,000

Current teaching: 

  • Climate Change: Convergence of Disciplines; SAS 25 (winter quarter)
  • Climate Change: Convergence of Disciplines; SAS 25v (winter and spring quarters)
  • Developing Digital Communication Skills in Agricultural, Environmental, and Human Sciences; SAS 190X (fall quarter)

External activities that contribute to scholarship:

  • Keynote Speaker, Root Physiology, CSSA Annual Meeting, Tampa, 2017
  • Keynote Speaker, Plant Science Central Conference, Massey University, New Zealand, 2017
  • Keynote Speaker, Annual IWYP Science Program Conference, Obregon, Mexico, 2017
  • Keynote Speaker, NIFA-IWYP Project Director Meeting, San Diego, 2017
  • Proposal Review Panel, USDA Photosynthetic Efficiency & Nutrient Utilization, 2016
  • Keynote Speaker, Third International Symposium on Nitrogen Nutrition of Plants, Montpellier, 2016
  • Keynote Speaker, Plant Biotech Denmark, Copenhagen, 2016
  • Education Working Group, UC Global Climate Leadership Council, UC Davis Faculty Representative, 2015
  • Science Working Group, NSF N-cycle Workgroup, 2015
  • Proposal Review Panel, USDA Photosynthetic Efficiency & Nutrient Utilization, 2015
  • Keynote Speaker, Online Courses on Climate Change, AESS Annual Meeting, San Diego, 2015
  • Expert Testimony, Technology in Higher Education, California Senate Committee, 2015
  • Keynote Speaker, Crop Physiology & Metabolism, CSSA Annual Meeting, Long Beach, 2014

Prizes, Awards, Honors

  • Endowed Professorship, John B. Orr Endowed Chair in Environmental Plant Biology, 2014

Google Scholar


Social media links: 


  • Plant physiological ecology
  • Environmental stress
  • Food security
  • Climate change
  • Agricultural sustainability
  • Plant nutrient relations
  • Plant carbon fixation
  • Plant nitrogen acquisition
  • Photorespiration
  • Genome-wide association studies
  • Quantitative trait loci