Metabolic Regulation of Chloroplastic Respiration of        Carbohydrates
{'Code': '08070400', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'MCB', 'LongName': 'Div Of Molecular and Cellular Bioscience'}}
{'SignBlockName': 'Kamal Shukla', 'PO_EMAI': None, 'PO_PHON': None}
The primary focus of this research is the retention of                  photosynthetic activity during extended photosynthesis and                      during dark intervals.  The biological test materials are                       isolated spinach and Chlamydomonas chloroplasts and the parent                  tissues.  The carbon dioxide fixing capability of the isolated                  intact spinach chloroplast falls off during photosynthesis                      after approximately 2-40 minutes, even though a functional                      electron transport chain and activity of stromal enzymes of the                 Calvin cycle are maintained.  Chloroplasts kept in the dark for                 10-20 minutes also lose their subsequent photosynthetic carbon                  dioxide fixing activity.  Addition of a complex between                         magnesium ions and ATP or a chloroplastic respirable substrate                  to the external medium during photosynthesis or during the dark                 phase prior to photosynthesis allows retention of                               photosynthetic activity.  Other nucleotides will not substitute                 for ATP nor do non-respirable chloroplastic substrates function                 in this capacity.  Similarly, pre-treatment of the darkended                    spinach leaf results in an inactivation of the carbon dioxide                   fixing capacity.  The level of inactivation seems to depend                     upon the nutritional status (perhaps carbohydrate content) of                   the leaf.  Inactivation is extremely pH dependent as is                         senescence of the chloroplast.  The basic events that result in                 the loss of photosynthetic carbon dioxide fixation will be                      elucidated as well as the underlying principles of the                          protective mechanisms.                                                                                                                                                  This research should provide substantial information                    supporting the concept that the retention of chloroplastic                      carbon dioxide fixing activity is dependent upon                                extrachloroplastic events such as cellular respiration and, to                  a limited extent, on chloroplastic respiration.  Separation of                  the chloroplast from these events leads to its rapid                            irreversible destruction unless the organelle is protected by                   the products of respiration generated in the mitochondrion or                   within the organelle by starch break-down.  The linkage of                      chloroplastic competency with other cellular events will add a                  basic component to our understanding of stress physiology, i.e.                 water status, temperature, ionic balance and other factors.
{'FirstName': 'Martin', 'LastName': 'Gibbs', 'PI_MID_INIT': None, 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Martin Gibbs', 'EmailAddress': None, 'NSF_ID': '000214132', 'StartDate': '07/15/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Brandeis University', 'CityName': 'WALTHAM', 'ZipCode': '024532728', 'PhoneNumber': '7817362121', 'StreetAddress': '415 SOUTH ST', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Massachusetts', 'StateCode': 'MA', 'CONGRESSDISTRICT': '05', 'CONGRESS_DISTRICT_ORG': 'MA05', 'ORG_UEI_NUM': 'MXLZGAMFEKN5', 'ORG_LGL_BUS_NAME': 'BRANDEIS UNIVERSITY', 'ORG_PRNT_UEI_NUM': 'JLC9RHNT9479'}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '1144', 'Text': 'Molecular Biophysics'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8703506.xml'}