Salt Stress Induces Differential Regulation of the Phenylpropanoid Pathway in Olea europaea cultivars Frantoio (salt-tolerant) and Leccino (salt-sensitive)
Document Type
Article
Journal/Book Title/Conference
Journal of Plant Physiology
Volume
204
Publisher
Elsevier GmbH
Publication Date
7-27-2016
First Page
8
Last Page
15
Abstract
Olive tree (Olea europaea L.) is an important crop in the Mediterranean Basin where drought and salinity are two of the main factors affecting plant productivity. Despite several studies have reported different responses of various olive tree cultivars to salt stress, the mechanisms that convey tolerance and sensitivity remain largely unknown. To investigate this issue, potted olive plants of Leccino (salt-sensitive) and Frantoio (salt-tolerant) cultivars were grown in a phytotron chamber and treated with 0, 60 and 120 mM NaCl. After forty days of treatment, growth analysis was performed and the concentration of sodium in root, stem and leaves was measured by atomic absorption spectroscopy. Phenolic compounds were extracted using methanol, hydrolyzed with butanol-HCl, and quercetin and kaempferol quantified via high performance liquid-chromatography-electrospray-mass spectrometry (HPLC-ESI‚øøMS) and HPLC-q-Time of Flight-MS analyses. In addition, the transcripts levels of five key genes of the phenylpropanoid pathway were measured by quantitative Real-Time PCR. The results of this study corroborate the previous observations, which showed that Frantoio and Leccino differ in allocating sodium in root and leaves. This study also revealed that phenolic compounds remain stable or are strongly depleted under long-time treatment with sodium in Leccino, despite a strong up-regulation of key genes of the phenylpropanoid pathway was observed. Frantoio instead, showed a less intense up-regulation of the phenylpropanoid genes but overall higher content of phenolic compounds. These data suggest that Frantoio copes with the toxicity imposed by elevated sodium not only with mechanisms of Na+ exclusion, but also promptly allocating effective and adequate antioxidant compounds to more sensitive organs.
Recommended Citation
Rossi L*, Borghi M*, Francini A, Lin X, Xie DY, Sebastiani L (2016). Salt stress induces differential regulation of the phenylpropanoid pathway in Olea europaea cultivars Frantoio (salt-tolerant) and Leccino (salt-sensitive) Journal of Plant Physiology (204) 8-15