Phenolic compounds and properties of antioxidants in grapevine roots (Vitis vinifera L.) under drought stress followed by recovery

Abstract

Grapevine seedlings<em> Vitis vinifera</em> were grown in a greenhouse under optimum conditions (soil moisture ca 70%) and under drought stress (soil moisture ca 35%). In addition, some of the plants subjected to drought underwent subsequent regeneration under optimum conditions. Drought stress caused accumulation of total phenolic compounds in grapevine roots, which may indicate that these compounds play an important role in the adaptation of roots to growth under stress conditions. Phenolic acids found in the roots occurred in the ester-bound form only. p-coumaric acid was present in the highest concentrations (6.2 to 10.5 µg/g fresh matter). The content of ferulic acid was lower, ranging from 2.4 to 4.6 µg/g fresh matter. The lowest concentration in grapevine roots was achieved by caffeic acid (2.4 to 2.9 µg/g fresh matter). The levels of p-coumaric and ferulic acids in roots rose significantly under the drought stress, while the concentration of caffeic acid increased during the post-drought recovery period. This may suggest that some of the phenolic acids protect plants under stress conditions. All the extracts from grapevine roots had antioxidative properties, but the antiradical activity of the extracts obtained from roots subjected to drought stress was inferior to the control. The same extracts were also characterised by depressed reducing power. The results imply that tolerance of grapevine to soil drought may be associated with the value of antioxidative potential in root tissues of these plants

Changes in the composition of phenolic compounds and antioxidant properties of grapevine roots and leaves (Vitis vinifera L.) under continuous of long-term drought stress

“…The asterisks designate significant differences for dependent samples at p \ 0.01 (double asterisks), at p \ 0.01 (triple asterisks) Similar results were obtained in earlier research on seedlings of V. vinifera exposed to chilling stress. The total content of phenolics, tannins and phenolic acids in stress sample was lower than in control sample (Weidner et al 2009b). Furthermore, Amarowicz et al (2010) observed the same trend in leaves of V. vinifera subjected to lowtemperature stress.…”

“…Other experiments have demonstrated that chilling stress did not have any major effect on the total content of phenolic compounds in pea roots, but it significantly decreased the content of flavone (Rudikowskaya et al 2008). Many authors demonstrated that the production of phenols in plant tissues rises under abiotic stress conditions (Dixon and Paiva 1995;Janas et al 2002;Wróbel et al 2005;Weidner et al 2009a). Such large discrepancies in experimental results can be attributed to differences in abiotic stresses, e.g.…”

“…In addition, depressed levels of the ester-bound form of p-coumaric, ferulic and caffeic acids have also been observed in roots of V. vinifera exposed to chilling stress. p-Coumaric acid was the most abundant and caffeic acid the least abundant phenolic in tissues of such roots (Weidner et al 2009b). Solecka (1997) claims that the presence of larger concentrations of phenolic acids in ester-or glycoside-bound forms in tissues is less toxic to plants, than the free forms.…”

“…type of stress, its intensity, its duration, the stages of plant development (in general, the early stages of germination and plant development are the least tolerant to stress) and the biological material, e.g. whole seedlings or different parts of plants, such as roots or leaves, which are characterized by a great diversity of secondary metabolites (Weidner et al 2009a).…”

“…This group of compounds protects cells against the negative effects of ROS as well as against lipid peroxidation, protein denaturation and DNA damage (Kranner et al 2002;Mittler 2002;Allakhverdiev et al 2008). In turn, environmental stress can cause a decline (Weidner et al 2007(Weidner et al , 2009b or an increase (Wróbel et al 2005;Weidner et al 2009a) in the content of phenolic compounds in a cell. Phenolic compounds can scavenge ROS (Amarowicz et al , 2004Negro et al 2003;Caillet et al 2006;Amarowicz and Weidner 2009), they form complexes with the metals, which catalyse oxygenation reactions and inhibit activity of oxidizing enzymes (Elavarthi and Martin 2010).…”