Please use this identifier to cite or link to this item:
|Title: ||Tracking biochemical changes during adventitious root formation in olive (Olea europaea L.)|
|Authors: ||Porfírio, S.|
Calado, M. L.
Cabrita, M. J.
|Keywords: ||Indole-3-acetic acid (IAA)|
Indole-3-butyric acid (IBA)
Salicylhydroxamic acid (SHAM)
Phenylpropanoid biosynthetic pathway
|Issue Date: ||6-Apr-2016|
|Citation: ||Porfírio, S., Calado, M.L., Noceda, C., Cabrita, M.J., da Silva, M.G., Azadie, P., Peixe, A.(2016)Tracking biochemical changes during adventitious root formation in olive (Olea europaea L.), Scientia Horticulturae, 204, 41–53|
|Abstract: ||The activity of oxidative enzymes and the levels of free auxins were determined during adventitious root formation in olive explants. Rooting trials were performed both with in vitro-cultured micro shoots of the cultivar ‘Galega Vulgar’, treated with indole-3-butyric acid (IBA) and with salicylhydroxamic acid(SHAM) + IBA, as well as with semi-hardwood cuttings of the cultivars ‘Galega Vulgar’ (difficult-to-root)and ‘Cobrançosa’ (easy-to-root), treated with IBA. The auxin (IBA) was used in all experiments as a rooting promoter, while SHAM was used in micropropagation trials as rooting inhibitor, providing a negative control. Free indole-3-acetic acid (IAA) and IBA concentrations were determined in microshoots, as well as in semi-hardwood cuttings, throughout the rooting period at pre-established time-points. At the sametime-points, the enzymatic activity of polyphenol oxidases (PPO), peroxidases (POX), and IAA oxidase(IAAox) was evaluated in the microshoots. Microshoots treated with SHAM + IBA revealed higher POX and IAAox activity, as well as lower PPO activity, than those treated only with IBA. IAA levels were higher in IBA-treated microshoots during induction phase, but lower during early initiation phase. Incontrast, free IBA levels were higher in microshoots treated with SHAM + IBA during induction, but lower during initiation. A similar pattern of free auxin levels was observed in semi-hardwood cuttings of the two contrasting cultivars under evaluation. The similarities found on the auxin patterns of microshoots treated with SHAM and those of semi-hardwood cuttings of the difficult-to-root olive cultivar allow considering SHAM a reliable control for when simulation of a difficult-to-root behavior is necessary. The inhibitory effect of SHAM in root formation could be related with 1) the inhibition of alternative oxidase(AOX), leading to a down regulation of phenylpropanoid biosynthetic pathways, which would decrease the concentration of phenolic substrates for PPO; 2) an increase in IAAox activity resulting in lower free IAA levels or; 3) a defective conversion of IBA into IAA.|
|Appears in Collections:||FIT - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica|
MED - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.