INVESTIGATORS: Maria Harrison (PI), Zhangjun Fei
INSTITUTIONS: Boyce Thompson Institute for Plant Research, Ithaca, New York
PROJECT SUMMARY: Fertilizers comprise a significant proportion of biofeedstock production costs and large-scale fertilizer use has many negative environmental consequences. If biofeedstock production is to be economically viable and environmentally sustainable, increasing the efficiency of mineral nutrient acquisition is an important priority. One approach to this is to harness soil microorganisms, in particular, arbuscular mycorrhizal fungi, with which plants form stable mutualistic symbioses. Two major benefits of AM symbiosis for the plant are increased acquisition of essential mineral nutrients, phosphorus (P) and nitrogen (N), but there are also other positive effects, including increased tolerance to various biotic and abiotic stresses. Currently, knowledge of genes that control AM symbiosis in feedstock species is limited. The overall goals of the proposed research are to understand the genetic basis of AM symbiosis in feedstocks through studies of a feedstock model species, Brachypodium distachyon, as well as sorghum, a feedstock species.
Our first objective is to evaluate the function of candidate proteins that potentially control development of the symbiosis and symbiotic P and N transport respectively. The function of these proteins during symbiosis will be assessed using genetic approaches in the model species, B. distachyon. Mutant B. distachyon plants lacking functional copies of these proteins will be identified. These mutants will then be assessed for symbiotic development, acquisition of N and P through the symbiosis, and plant productivity. These experiments will allow the identification of proteins that play key roles in symbiotic mineral nutrient acquisition.
Our second objective is to evaluate AM symbiosis in diverse sweet and cellulosic (bioenergy) sorghum lines. Responses to AM symbiosis including development of symbiosis, symbiotic mineral nutrient acquisition and increases in shoot biomass will be evaluated. For a selection of these lines, root and shoot transcriptional responses to symbiosis will be analyzed. The transcript profiles will provide insights into AM symbiosis and the effects of plant genotype on symbiotic gene expression.
The data generated in these experiments will contribute to a fundamental understanding of symbiotic N and P acquisition in feedstocks and will provide insights into variation in responses to AM symbiosis in diverse sorghum genotypes. This knowledge will provide a foundation for future association mapping studies for symbiosis in sorghum. Ultimately this will inform feedstock breeding programs with the end result of enhancing the sustainability of feedstock production.
Name: Harrison, Maria