Determination of senescence in plants
Senescence is interpreted by some authors to be a genetically controlled process; nevertheless, there is evidence that the internal and external environments are also involved in its control. Thus, for example, the increase in the C/N ratio, an alteration of living matter characteristic of senescenc...
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| Format: | Online |
| Language: | spa |
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Facultad de Ciencias Agropecuarias
1992
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| Online Access: | https://revistas.unc.edu.ar/index.php/agris/article/view/2260 |
| _version_ | 1839026401942962176 |
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| author | Trippi, Victorio S. |
| author_facet | Trippi, Victorio S. |
| author_sort | Trippi, Victorio S. |
| collection | Portal de Revistas |
| description | Senescence is interpreted by some authors to be a genetically controlled process; nevertheless, there is evidence that the internal and external environments are also involved in its control. Thus, for example, the increase in the C/N ratio, an alteration of living matter characteristic of senescence, could originate from an inhibition of nitrate reductase by high oxygen pressures. The evolution of senescence parameters under the action of oxygen pressure indicates that the process accelerates directly in correlation with the concentration of this gas. Likewise, free radicals and enzymes seem to be involved in the degradation of chlorophylls and proteins. In the case of chlorophylls, all known toxic species of oxygen (O₂, ¹O₂, HO·, H₂O₂) can bleach the pigment, and enzymatic degradation itself involves the participation of free radicals.In regards to proteolysis, four proteases have been detected in Avena chloroplasts, among them an endopeptidase whose activity increases under oxidative conditions. The sensitivity of some chloroplast proteins to the action of free radicals has also been established. |
| format | Online |
| id | oai:ojs.revistas.unc.edu.ar:article-2260 |
| institution | Universidad Nacional de Cordoba |
| language | spa |
| publishDate | 1992 |
| publisher | Facultad de Ciencias Agropecuarias |
| record_format | ojs |
| spelling | oai:ojs.revistas.unc.edu.ar:article-22602025-06-18T15:38:13Z Determination of senescence in plants La determinación de la senescencia en las plantas Trippi, Victorio S. senescence oxidations energy metabolism proteolysis degradation of chlorophylls senescencia oxidaciones metabolismo energético proteólisis degradación de clorofilas Senescence is interpreted by some authors to be a genetically controlled process; nevertheless, there is evidence that the internal and external environments are also involved in its control. Thus, for example, the increase in the C/N ratio, an alteration of living matter characteristic of senescence, could originate from an inhibition of nitrate reductase by high oxygen pressures. The evolution of senescence parameters under the action of oxygen pressure indicates that the process accelerates directly in correlation with the concentration of this gas. Likewise, free radicals and enzymes seem to be involved in the degradation of chlorophylls and proteins. In the case of chlorophylls, all known toxic species of oxygen (O₂, ¹O₂, HO·, H₂O₂) can bleach the pigment, and enzymatic degradation itself involves the participation of free radicals.In regards to proteolysis, four proteases have been detected in Avena chloroplasts, among them an endopeptidase whose activity increases under oxidative conditions. The sensitivity of some chloroplast proteins to the action of free radicals has also been established. La senescencia es interpretada por algunos autores como un proceso controlado genéticamente; sin embargo, hay evidencias de que el ambiente interno y externo también están implicados en dicho control. Así, por ejemplo, el aumento de la relación C/N, que implica una alteración de la materia viva, característica del proceso de senescencia, podría originarse en una inhibición de la actividad nitrato reductasa por altas presiones de oxígeno. La evolución de los parámetros de senescencia bajo la acción de la presión de oxígeno evidencia que el proceso se acelera en relación directa con la concentración del gas. Asimismo, en la degradación de clorofilas y proteínas aparecen implicados radicales libres y enzimas. En el caso de las clorofilas, todas las especies tóxicas del oxígeno conocidas (O₂, ¹O₂, HO·, H₂O₂) pueden blanquear el pigmento, y la misma degradación enzimática se lleva a cabo con la participación de radicales libres. Por lo que concierne a la proteólisis, se han podido establecer cuatro proteasas en el cloroplasto de avena, entre ellas una endopeptidasa cuya actividad incrementa bajo condiciones oxidantes. Asimismo, pudo constatarse la sensibilidad de algunas proteínas del cloroplasto a la acción de radicales libres. Facultad de Ciencias Agropecuarias 1992-12-01 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion application/pdf https://revistas.unc.edu.ar/index.php/agris/article/view/2260 10.31047/1668.298x.v9.n1.2260 AgriScientia; Vol. 9 No. 1 (1992); 49-53 AgriScientia; Vol. 9 Núm. 1 (1992); 49-53 1668-298X 10.31047/1668.298x.v9.n1 spa https://revistas.unc.edu.ar/index.php/agris/article/view/2260/1207 Derechos de autor 1992 Victorio S. Trippi https://creativecommons.org/licenses/by-sa/4.0 |
| spellingShingle | senescence oxidations energy metabolism proteolysis degradation of chlorophylls senescencia oxidaciones metabolismo energético proteólisis degradación de clorofilas Trippi, Victorio S. Determination of senescence in plants |
| title | Determination of senescence in plants |
| title_alt | La determinación de la senescencia en las plantas |
| title_full | Determination of senescence in plants |
| title_fullStr | Determination of senescence in plants |
| title_full_unstemmed | Determination of senescence in plants |
| title_short | Determination of senescence in plants |
| title_sort | determination of senescence in plants |
| topic | senescence oxidations energy metabolism proteolysis degradation of chlorophylls senescencia oxidaciones metabolismo energético proteólisis degradación de clorofilas |
| topic_facet | senescence oxidations energy metabolism proteolysis degradation of chlorophylls senescencia oxidaciones metabolismo energético proteólisis degradación de clorofilas |
| url | https://revistas.unc.edu.ar/index.php/agris/article/view/2260 |
| work_keys_str_mv | AT trippivictorios determinationofsenescenceinplants AT trippivictorios ladeterminaciondelasenescenciaenlasplantas |