PMID- 24421064 OWN - NLM STAT- PubMed-not-MEDLINE DCOM- 20140115 LR - 20240109 IS - 0166-8595 (Print) IS - 0166-8595 (Linking) VI - 23 IP - 2 DP - 1990 Feb TI - Changes in ribulosebisphosphate carboxylase/oxygenase and ribulose 5-phosphate kinase abundances and photosynthetic capacity during leaf senescence. PG - 223-30 LID - 10.1007/BF00035013 [doi] AB - The abundances of ribulose-1,5-bisphosphate carboxylate/oxygenase (Rubisco) and ribulose-5-phosphate (Ru5P) kinase in field-grown soybean (Glycine max L. Merr.) leaves were quantified by a Western blot technique and related to changes in chlorophyll and photosynthetic capacity during senescence. Even though the leaf content of Rubisco was approximately 80-fold greater than that of Ru5P kinase, the decline in the levels of these two Calvin cycle enzymes occurred in parallel during the senescence of the leaves. Moreover, the decrease in the content of Rubisco was accompanied by parallel decreases of both the large and small subunits of this enzyme but not by an accumulation of altered large or small subunit isoforms. With increasing senescence, decreases in abundances of Rubisco, Ru5P kinase and chlorophyll were closely correlated with the decline in photosynthetic capacity; thus, the specific photosynthetic capacity when expressed per abundance of any of these parameters was rather constant despite an 8-fold decrease in photosynthetic capacity. These results suggest that during senescence of soybean leaves the chloroplast is subject to autolysis by mechanisms causing an approximately 80-fold greater rate of loss of Rubisco than Ru5P kinase. FAU - Crafts-Brandner, S J AU - Crafts-Brandner SJ AD - Agricultural Research Service, United States Department of Agriculture, 40546, Lexington, Kentucky, USA. FAU - Salvucci, M E AU - Salvucci ME FAU - Egli, D B AU - Egli DB LA - eng PT - Journal Article PL - Netherlands TA - Photosynth Res JT - Photosynthesis research JID - 100954728 EDAT- 1990/02/01 00:00 MHDA- 1990/02/01 00:01 CRDT- 2014/01/15 06:00 PHST- 2014/01/15 06:00 [entrez] PHST- 1990/02/01 00:00 [pubmed] PHST- 1990/02/01 00:01 [medline] AID - 10.1007/BF00035013 [doi] PST - ppublish SO - Photosynth Res. 1990 Feb;23(2):223-30. doi: 10.1007/BF00035013.