Sneak Peak at How Stressed Plants Mobilize the Resources

The Science

The ability of plants to withstand stresses depends on a coordinated chain of events from the molecular level to the whole plant. Our ability to effectively develop plants as sustainable feedstocks for biofuels requires that we understand the impacts of these stresses. DOE-funded researchers at Brookhaven National Laboratory and Tufts University have shown that plants re-allocate a significant portion of their below-ground nitrogen resources when defense mechanisms are triggered in response to herbivory (being eaten or under attack). Using a combination of short-lived PET (positron emission tomography) radioisotopes, including carbon-11 and nitrogen-13, administered to leaves of intact tomato plants, they were able to “see” the movement of sugars and amino acids away from the simulated attack sites. The results argue for strong physiological adaptive responses by plants as a tolerance defense mechanism. This research has important implications for bioenergy feedstock development since the next generation of plant feedstocks will need to withstand many environmental challenges including drought, limited nutrients and disease. Modifying plants with the right defense traits could improve the robustness of future feedstocks. The research is reported in the November issue of New Phytologist, along with a commentary on the significance of the new findings.

Summary

Herbivory entails a direct loss of resources and a reduction in future resource acquisition when roots or leaves are affected, and should be expected to negatively impact plant performance. These results suggest that plants may also respond to leaf damage through a shift in resource allocation by which nitrogen (N) is re-allocated from damaged leaves to the roots. They argue that N is thus safe from folivores and available for regrowth once the threat of herbivory has passed.

BER Program Manager

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]

References

Gómez, S., R.A. Ferrieri, M. Schueller, and C. M. Orians. 2010. “Methyl Jasmonate Elicits Rapid Changes in Carbon and Nitrogen Dynamics in Tomato,” New Phytologist 188, 835-44. DOI:10.1111/j.1469-8137.2010.03414.x.

Anten, N.P.R., and R. Pierik. 2010. “Moving Resources Away From the Herbivore: Regulation and Adaptive Significance,” New Phytologist 188, 643-45. DOI:10.1111/j.1469-8137.2010.03506.x.