caa a22 4500 477100147 CHVBK 20180405111538.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF00200298 doi (NATIONALLICENCE)springer-10.1007/BF00200298 Coordination of protein and mRNA abundances of stromal enzymes and mRNA abundances of the Clp protease subunits during senescence of Phaseolus vulgaris (L.) leaves [Elektronische Daten] [Steven Crafts-Brandner, Robert Klein, Patricia Klein, Regina Hölzer, Urs Feller] Our objective was to determine the coordination of transcript and/or protein abundances of stromal enzymes during leaf senescence. First trifolioliate leaves of Phaseolus vulgaris L. plants were sampled beginning at the time of full leaf expansion; at this same time, half of the plants were switched to a nutrient solution lacking N. Total RNA and soluble protein abundances decreased after full leaf expansion whereas chlorophyll abundance remained constant; N stress enhanced the decline in these traits. Abundances of ribulose-1,5-bisposphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39), Rubisco activase and phosphoribulokinase (Ru5P kinase; EC 2.7.1.19) decreased after full leaf expansion in a coordinated manner for both treatments. In contrast, adenosine diphosphate glucose (ADPGlc) pyrophosphorylase (EC 2.7.7.27) abundance was relatively constant during natural senescence but did decline similar to the other enzymes under N stress. Northern analyses indicated that transcript abundances for all enzymes declined markedly on a fresh-weight basis just after full leaf expansion. This rapid decline was particularly strong for the Rubisco small subunit (rbcS) transcript. The decline was enhanced by N stress for rbcS and Rubisco activase (rca), but not for Ru5P kinase (prk) and ADPGlc pyrophosphorylase (agp). Transcripts of the Clp protease subunits clpC and clpP declined in abundance just after full leaf expansion, similar to the other mRNA species. When Northern blots were analyzed using equal RNA loads, rbcS transcripts still declined markedly just after full leaf expansion whereas rca and clpC transcripts increased over time. The results indicated that senescence was initiated near the time of full leaf expansion, was accelerated by N stress, and was characterized by large decline in transcripts of stromal enzymes. The decreased mRNA abundances were in general associated with steadily declining stromal protein abundances, with ADPGlc pyrophosphorylase being the notable exception. Transcript analyses for the Clp subunits supported a recent report (Shanklin et al., 1995, Plant Cell 7: 1713-1722) indicating that the Clp protease subunits were constitutive throughout development and suggested that ClpC and ClpP do not function as a senescence-specific proteolytic system in Phaseolus. Springer-Verlag, 1996 Clp (protease) nationallicence Gene expression nationallicence Leaf sen nationallicence escence nationallicence Phaseolus (senescence) nationallicence Stromal enzymes nationallicence ADPGlc : adenosine diphosphate glucose nationallicence agp,prk, rbcS, rca : genes encoding the large subunit of ADPGlc pyro-phosphorylase, Ru5P kinase, the small subunit of Rubisco and Rubisco activase, respectively nationallicence Ru5P kinase : phosphoribulo-kinase nationallicence Rubisco : ribulose-1,5-bisphosphate carboxylase/oxygenase nationallicence Crafts-Brandner Steven USDA-ARS Western Cotton Research Laboratory, 4135 E. Broadway Road, 85040-8830, Phoenix, AZ, USA aut Klein Robert USDA-ARS Eastern Regional Research Laboratory, 19118, Philadelphia, PA, USA aut Klein Patricia USDA-ARS Eastern Regional Research Laboratory, 19118, Philadelphia, PA, USA aut Hölzer Regina Institute of Plant Physiology, University of Bern, CH-3013, Bern, Switzerland aut Feller Urs Institute of Plant Physiology, University of Bern, CH-3013, Bern, Switzerland aut Planta Springer-Verlag 200/3(1996-11-01), 312-318 0032-0935 200:3<312 1996 200 425 https://doi.org/10.1007/BF00200298 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00200298 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crafts-Brandner Steven USDA-ARS Western Cotton Research Laboratory, 4135 E. Broadway Road, 85040-8830, Phoenix, AZ, USA aut NATIONALLICENCE 700 1- Klein Robert USDA-ARS Eastern Regional Research Laboratory, 19118, Philadelphia, PA, USA aut NATIONALLICENCE 700 1- Klein Patricia USDA-ARS Eastern Regional Research Laboratory, 19118, Philadelphia, PA, USA aut NATIONALLICENCE 700 1- Hölzer Regina Institute of Plant Physiology, University of Bern, CH-3013, Bern, Switzerland aut NATIONALLICENCE 700 1- Feller Urs Institute of Plant Physiology, University of Bern, CH-3013, Bern, Switzerland aut NATIONALLICENCE 773 0- Planta Springer-Verlag 200/3(1996-11-01), 312-318 0032-0935 200:3<312 1996 200 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer