Dynamic precision phenotyping reveals mechanism of crop tolerance to root herbivory

Authors: QU, W. - Cornell University; ROBERT, C.A.M. - University Of Bern; ERB, M. - University Of Bern; Hibbard, Bruce; PAVEN, M. - Johannes Gutenberg University; GLEEDE, T. - Johannes Gutenberg University; RIEHL, B. - Johannes Gutenberg University; KERSTING, L. - Johannes Gutenberg University; CANKAYA, AYLIN - Johannes Gutenberg University; KUNERT, ANNA - Johannes Gutenberg University; XU, Y - Brookhaven National Laboratory; SCHUELLER, M. - Brookhaven National Laboratory; SHEA, C. - Brookhaven National Laboratory; ALEXOFF, D. - Brookhaven National Laboratory; LEE, S. - Brookhaven National Laboratory; FOWLER, J. - Brookhaven National Laboratory; FERRIERI, R. - Brookhaven National Laboratory

Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2016
Publication Date: 10/1/2016
Publication URL: http://handle.nal.usda.gov/10113/63261
Citation: Qu, W., Robert, C., Erb, M., Hibbard, B.E., Paven, M., Gleede, T., Riehl, B., Kersting, L., Cankaya, A.S., Kunert, A.T., Xu, Y., Schueller, M.J., Shea, C., Alexoff, D., Lee, S.J., Fowler, J.S., Ferrieri, R.A. 2016. Dynamic precision phenotyping reveals mechanism of crop tolerance to root herbivory. Plant Physiology. 172:776-788.

Interpretive Summary: The western corn rootworm (WCR) is a major pest of corn. This pest has repeatedly shown its resilience and adaptability not only to traditional crop management strategies including chemical pesticides and crop rotation, but also to deployment of GMOs. Because damage caused by western corn rootworm can be significant, resulting in huge agricultural losses, mounting concerns over global food securities are now forcing the search for rapid cost-effective solutions to the problem. Breeding tolerant crop lines is one approach, but is time consuming. Streamlining breeding selections requires more guidance aided by rigorous phenotyping (assessment of the plant response to WCR). Unfortunately, present phenotyping tools tell us little about the ability of root systems to adapt to and function in response to exposure to this pest. In this research we used a new and dynamic, precision phenotyping tool which leverages the radioactive decay of carbon-11 coupled with a new imaging technology (positron emission tomography), to spatially and temporally map the physiological and biochemical response that generate an increase in branch root regrowth after insect feeding as a possible means for maize tolerance to WCR. Our findings point to the regrowth response as being controlled by the plant growth hormone auxin, and also revealed that regional tissue auxin biosynthesis, up-regulated by glutamine availability, stimulates this response in maize. These findings could enable breeders and geneticists to speed the development of natural tolerance to western corn rootworm larval feeding

Technical Abstract: The western corn rootworm, Diabrotica virgifera virgifera (LeConte) is a major pest of maize, Zea mays L. Over the years, this pest has repeatedly shown its resilience and adaptability not only to traditional crop management strategies including chemical pesticides and crop rotation, but also to deployment of GMOs. Because damage caused by D. virgifera can be significant resulting in huge agricultural losses, mounting concerns over global food securities are now forcing the search for rapid cost-effective solutions to the problem. Breeding tolerant crop lines is one approach, but is time consuming. Streamlining breeding selections requires more guidance aided by rigorous phenotyping. Unfortunately, present phenotyping tools tell us little about the plasticity of root systems impacted by this pest. Here we used dynamic, precision phenotyping which leveraged the radioactive decay of carbon-11 coupled with positron emission tomography, multi-tracer root radiography and radiometabolite flux analysis to spatially and temporally map the physiological and biochemical basis for branch root regrowth in maize tolerance. Our findings point to the growth hormone auxin, and reveal that regional tissue auxin biosynthesis, up-regulated by glutamine availability, stimulates this response in maize.