Liriodendron tulipifera (known as the tulip tree) is a woody species that has been previously classified as sensitive to ozone (O3) in terms of visible leaf injuries and photosynthetic primary reactions. The objective of this work is to give a thorough description of the detoxification mechanisms that are at the basis of O3sensitivity. Biochemical and molecular markers were used to characterize the response of 1-year-old saplings exposed to O3(120 ppb, 5 h day−1, for 45 consecutive days) under controlled conditions. O3effects resulted in a less efficient metabolism of Halliwell-Asada cycle as confirmed by the diminished capacity to convert the oxidized forms of ascorbate and glutathione in the reduced ones (AsA and GSH, respectively). The reduced activity of AsA and GSH regenerating enzymes indicates that de novo AsA biosynthesis occurred. This compound could be a cofactor of several plant-specific enzymes that are involved in the early part of the phenylpropanoid and flavonoid biosynthesis pathway, as confirmed by the significant rise of PAL activity (+75%). The induction of the defence-related secondary metabolites (in particular, rutin and caffeic acid were about threefold higher) and the concomitant increase in transcript levels of PAL and CHS genes (+120 and 30%, respectively) suggest that L. tulipifera utilized this route in order to partially counteract the O3-induced oxidative damage.

What about the detoxification mechanisms underlying ozone sensitivity in Liriodendron tulipifera?

Pellegrini, Elisa
Primo
;
Campanella, Alessandra;Cotrozzi, Lorenzo;Tonelli, Mariagrazia;Nali, Cristina
;
Lorenzini, Giacomo
Ultimo
2018-01-01

Abstract

Liriodendron tulipifera (known as the tulip tree) is a woody species that has been previously classified as sensitive to ozone (O3) in terms of visible leaf injuries and photosynthetic primary reactions. The objective of this work is to give a thorough description of the detoxification mechanisms that are at the basis of O3sensitivity. Biochemical and molecular markers were used to characterize the response of 1-year-old saplings exposed to O3(120 ppb, 5 h day−1, for 45 consecutive days) under controlled conditions. O3effects resulted in a less efficient metabolism of Halliwell-Asada cycle as confirmed by the diminished capacity to convert the oxidized forms of ascorbate and glutathione in the reduced ones (AsA and GSH, respectively). The reduced activity of AsA and GSH regenerating enzymes indicates that de novo AsA biosynthesis occurred. This compound could be a cofactor of several plant-specific enzymes that are involved in the early part of the phenylpropanoid and flavonoid biosynthesis pathway, as confirmed by the significant rise of PAL activity (+75%). The induction of the defence-related secondary metabolites (in particular, rutin and caffeic acid were about threefold higher) and the concomitant increase in transcript levels of PAL and CHS genes (+120 and 30%, respectively) suggest that L. tulipifera utilized this route in order to partially counteract the O3-induced oxidative damage.
2018
Pellegrini, Elisa; Campanella, Alessandra; Cotrozzi, Lorenzo; Tonelli, Mariagrazia; Nali, Cristina; Lorenzini, Giacomo
File in questo prodotto:
File Dimensione Formato  
Liriodendron.pdf

solo utenti autorizzati

Tipologia: Versione finale editoriale
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 2.4 MB
Formato Adobe PDF
2.4 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/899813
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 28
  • ???jsp.display-item.citation.isi??? 21
social impact