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Deciphering the Role of Sucrose Phosphate Synthase in Root Nodules of Medicago sativa (alfalfa)
Author(s) -
Grimes Martha Martinez,
Ortega Jose Luis,
SenguptaGopalan Champa
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.lb120
Subject(s) - sucrose synthase , root nodule , biochemistry , bacteria , sucrose , nitrogen fixation , biology , context (archaeology) , atp synthase , sinorhizobium meliloti , sucrose phosphate synthase , phosphate , enzyme , nitrogenase , medicago truncatula , symbiosis , genetics , invertase , paleontology
Leguminous plants, like alfalfa, can form a symbiotic relationship with a N fixing bacteria that can result in the formation root nodules. They have the ability to sustain the N fixing bacteria by providing optimal conditions for the bacterially encoded enzyme, nitrogenase, to reduce N to ammonia. The ammonia is then assimilated and exported to the rest of the plant. The plant provides the bacteria in the nodules with a source of C and energy in the form of sucrose in exchange for the fixed N. Sucrose Phosphate Synthase (SPS) catalyzes the penultimate step in sucrose biosynthesis and plays a key regulatory role in C partitioning in the pathway. Preliminary work form our lab has shown one isoform to have high SPS activity in the nodules, SPSA. To address the issue of what might be role of SPSA gene product in the nodules, we are using both immunolocalization and site of promoter function to localize the site of expression of SPSA in the nodules in context of N fixation, ammonia assimilation, and C metabolism. We are also using a genetic engineering approach to modulate the expression of SPS genes in a cell specific manner to monitor any changes in the function of the nodules.