Starch mutants of Chlamydomonas
- Univ. of Georgia, Athens (USA)
Wild type Chlamydomonas accumulates starch and triglycerides when grown under nitrogen limiting conditions. Toward elucidation of the mechanisms for control of starch biosynthesis, we isolated mutants impaired int he accumulation of storage carbohydrates. Chlamydomonas reinhardtii (strain ya-12) was mutagenized by UV irradiation and colonies were screened by iodine staining after growth in darkness. Mutants, denoted ais for altered in iodine staining, have been characterized by electron microscopy and assays for starch synthease, ADPG-pyrophosphorylase, phosphoglucose isomerase (PGI), phosphoglucomutase and fructose 1,6-bisphosphatase, and amylase activities. Transcript analysis of wild type and mutant RNAs with PGI, ADPG-pyrophosphorylase, and waxy probes have also been carried out. No deficiencies of any of these components have been detected. Furthermore, long-term cultures of ya-12 and ais-1d in nitrogen-limited chemostats have been studied; starch also does not accumulate in ais-1d under these conditions. Thus, the lesion affects an essential factor of unknown identity that is required for starch synthesis.
- OSTI ID:
- 5627859
- Report Number(s):
- CONF-9007196--
- Journal Information:
- Plant Physiology, Supplement; (USA), Journal Name: Plant Physiology, Supplement; (USA) Vol. 93:1; ISSN PPYSA; ISSN 0079-2241
- Country of Publication:
- United States
- Language:
- English
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