Dwarf mutants are useful to elucidate regulatory mechanisms of plant growth and development. A brachytic mutant, named lingering hope (linho), was recently isolated from sunflower (Helianthus annuus). The aim of this report is the characterization of the mutant through genetic, morphometric, physiological and gene expression analyses. The brachytic trait is controlled by a recessive gene. The reduction of plant height depends on shorter apical internodes. The mutant shows an altered ratio length/width of the leaf blade, chlorosis and defects in inflorescence development. The brachytic trait is not associated to a specific hormonal deficiency, but an increased level of several gibberellins is detected in leaves. Notably, the endogenous salicylic acid (SA) content in young leaves of the mutant is very high despite a low level of SA 2-O-β-D-glucoside (SAG). The CO2 assimilation rate significantly decreases in the second pair of leaves of linho, due to effects of both stomatal and non-stomatal constraints. In addition, the reduction of both actual and potential photochemical efficiency of photosystem II is associated with a reduced content of chlorophylls and carotenoids, a lower chlorophyll a to chlorophyll b ratio and a higher SA content. In comparison to wild type, linho shows a different pattern of gene expression with respect two pathogenesis-related genes and two genes involved in SA biosynthesis and SA metabolism. linho is the first mutant described in sunflower with altered SA metabolism and this genotype could be useful to improve information about the effects of high endogenous content of SA on plant development, reproductive growth and photosynthesis, in a major crop.
Characterization of lingering hope, a new brachytic mutant in sunflower (Helianthus annuus L.) with altered salicylic acid metabolism
Lorenzo Mariotti;Marco Fambrini;Piero Picciarelli;Claudio Pugliesi
2018-01-01
Abstract
Dwarf mutants are useful to elucidate regulatory mechanisms of plant growth and development. A brachytic mutant, named lingering hope (linho), was recently isolated from sunflower (Helianthus annuus). The aim of this report is the characterization of the mutant through genetic, morphometric, physiological and gene expression analyses. The brachytic trait is controlled by a recessive gene. The reduction of plant height depends on shorter apical internodes. The mutant shows an altered ratio length/width of the leaf blade, chlorosis and defects in inflorescence development. The brachytic trait is not associated to a specific hormonal deficiency, but an increased level of several gibberellins is detected in leaves. Notably, the endogenous salicylic acid (SA) content in young leaves of the mutant is very high despite a low level of SA 2-O-β-D-glucoside (SAG). The CO2 assimilation rate significantly decreases in the second pair of leaves of linho, due to effects of both stomatal and non-stomatal constraints. In addition, the reduction of both actual and potential photochemical efficiency of photosystem II is associated with a reduced content of chlorophylls and carotenoids, a lower chlorophyll a to chlorophyll b ratio and a higher SA content. In comparison to wild type, linho shows a different pattern of gene expression with respect two pathogenesis-related genes and two genes involved in SA biosynthesis and SA metabolism. linho is the first mutant described in sunflower with altered SA metabolism and this genotype could be useful to improve information about the effects of high endogenous content of SA on plant development, reproductive growth and photosynthesis, in a major crop.File | Dimensione | Formato | |
---|---|---|---|
PDF lingering hope.pdf
solo utenti autorizzati
Descrizione: PDF completo
Tipologia:
Versione finale editoriale
Licenza:
NON PUBBLICO - Accesso privato/ristretto
Dimensione
2.69 MB
Formato
Adobe PDF
|
2.69 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Mariotti et al 2018_JPPLinho.pdf
accesso aperto
Tipologia:
Documento in Post-print
Licenza:
Creative commons
Dimensione
2.09 MB
Formato
Adobe PDF
|
2.09 MB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.