Cellular and molecular aspects of quinoa leaf senescence.

Autor: López-Fernández MP; IBBEA (Instituto de Biodiversidad y Biología Experimental y Aplicada), CONICET (Consejo Nacional de Investigaciones Científicas Técnicas). Argentina; DBBE (Departamento de Biodiversidad y Biología Experimental), FCEN (Facultad de Ciencias Exactas y Naturales), UBA (Universidad de Buenos Aires), Int. Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina., Burrieza HP; IBBEA (Instituto de Biodiversidad y Biología Experimental y Aplicada), CONICET (Consejo Nacional de Investigaciones Científicas Técnicas). Argentina; DBBE (Departamento de Biodiversidad y Biología Experimental), FCEN (Facultad de Ciencias Exactas y Naturales), UBA (Universidad de Buenos Aires), Int. Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina., Rizzo AJ; DBBE (Departamento de Biodiversidad y Biología Experimental), FCEN (Facultad de Ciencias Exactas y Naturales), UBA (Universidad de Buenos Aires), Int. Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina., Martínez-Tosar LJ; IBBEA (Instituto de Biodiversidad y Biología Experimental y Aplicada), CONICET (Consejo Nacional de Investigaciones Científicas Técnicas). Argentina., Maldonado S; IBBEA (Instituto de Biodiversidad y Biología Experimental y Aplicada), CONICET (Consejo Nacional de Investigaciones Científicas Técnicas). Argentina; DBBE (Departamento de Biodiversidad y Biología Experimental), FCEN (Facultad de Ciencias Exactas y Naturales), UBA (Universidad de Buenos Aires), Int. Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina. Electronic address: saram@bg.fcen.uba.ar.
Jazyk: angličtina
Zdroj: Plant science : an international journal of experimental plant biology [Plant Sci] 2015 Sep; Vol. 238, pp. 178-87. Date of Electronic Publication: 2015 Jun 12.
DOI: 10.1016/j.plantsci.2015.06.003
Abstrakt: During leaf senescence, degradation of chloroplasts precede to changes in nuclei and other cytoplasmic organelles, RuBisCO stability is progressively lost, grana lose their structure, plastidial DNA becomes distorted and degraded, the number of plastoglobuli increases and abundant senescence-associated vesicles containing electronically dense particles emerge from chloroplasts pouring their content into the central vacuole. This study examines quinoa leaf tissues during development and senescence using a range of well-established markers of programmed cell death (PCD), including: morphological changes in nuclei and chloroplasts, degradation of RuBisCO, changes in chlorophyll content, DNA degradation, variations in ploidy levels, and changes in nuclease profiles. TUNEL reaction and DNA electrophoresis demonstrated that DNA fragmentation in nuclei occurs at early senescence, which correlates with induction of specific nucleases. During senescence, metabolic activity is high and nuclei endoreduplicate, peaking at 4C. At this time, TEM images showed some healthy nuclei with condensed chromatin and nucleoli. We have found that DNA fragmentation, induction of senescence-associated nucleases and endoreduplication take place during leaf senescence. This provides a starting point for further research aiming to identify key genes involved in the senescence of quinoa leaves.
(Published by Elsevier Ireland Ltd.)
Databáze: MEDLINE
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