Enhancement of Biological Nitrogen by Genetic               Manipulation of Rhizobium
{'Code': '08070100', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'MCB', 'LongName': 'Div Of Molecular and Cellular Bioscience'}}
{'SignBlockName': 'Philip Harriman', 'PO_EMAI': None, 'PO_PHON': None}
Studies in this program are focused in two areas:  (a) regulation               of expression of R. meliloti nitrogen fixation (nif) genes and                  (b) characterization of two symbiotically essential loci (ndv)                  and ndvB) required for nodule invasion in R. meliloti.  Both are                continuations of ongoing research and represent efforts to                      examine aspects of early and late stages of the developmental                   interaction between a Rhizobium species and its host legume.                                                                                                    Work on nif regulation will deal almost exclusively with                        molecular controls exerted upon and by the nifA gene.  As the                   central regulatory element governing nif transcription, nifA has                recently been shown to be the point at which regulation differs                 in Rhizobium from that observed in the free living nitrogen                     fixing bacterium Klebsiella pneumoniae.  Techniques have been                   developed that allow study nif regulation in R. meliloti in the                 absence of alfalfa and this capability has been used to identify                a new symbiotically essential locus controlling nifA expression.                This locus will be part of the present study.                                                                                                                   Structural and regulatory features of ndv genes will be                         investigated, as will pertinent aspects of the ndv mutant                       phenotype.  The overall objective is to ascertain the biochemical               nature of the defect in ndv mutants and thus the normal function                of ndv gene products.  Of particular importance will be studies                 related to the absence of a unique polysaccharide (B-l,2 glucan)                in ndv mutants and how this could relate to the decreased ability               of ndv mutants to attach to and invade alfalfa roots.
[{'FirstName': 'Gary', 'LastName': 'Ditta', 'PI_MID_INIT': 'S', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Gary S Ditta', 'EmailAddress': None, 'NSF_ID': '000329891', 'StartDate': '02/15/1988', 'EndDate': None, 'RoleCode': 'Co-Principal Investigator'}, {'FirstName': 'Donald', 'LastName': 'Helinski', 'PI_MID_INIT': 'R', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Donald R Helinski', 'EmailAddress': 'dhelinski@ucsd.edu', 'NSF_ID': '000228521', 'StartDate': '02/15/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}]
{'Name': 'University of California-San Diego', 'CityName': 'LA JOLLA', 'ZipCode': '920930021', 'PhoneNumber': '8585344896', 'StreetAddress': '9500 GILMAN DR', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'California', 'StateCode': 'CA', 'CONGRESSDISTRICT': '50', 'CONGRESS_DISTRICT_ORG': 'CA50', 'ORG_UEI_NUM': 'UYTTZT6G9DT1', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF CALIFORNIA, SAN DIEGO', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '1112', 'Text': 'Genetic Mechanisms'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8716673.xml'}