Antioxidant and anatomical responses in shoot culture of the apple rootstock MM 106 treated with NaCl, KCl, mannitol or sorbitol

Abstract

To determine whether the major influence of high salinity is caused by the osmotic component or by salinity-induced specific ion toxicity, we compared the effects of mannitol, sorbitol, NaCl and KCl (all in concentratuions corresponded to osmotic potential -1.0 MPa) on the antioxidant and anatomical responses of the apple rootstock MM 106 explants grown in the Murashige and Skoog (MS) medium. All the compounds had a significant influence on explant's mineral composition and reduced the leaf water content, whereas mannitol and salts decreased chlorophyll (Chl) content and increased proline content. Superoxide dismutase (SOD), peroxidase (POD) and non-enzymatic antioxidant activities as well as H 2 O 2 content were increased in the leaves and stems. In addition, in the leaves of explants exposed to NaCl an additional Mn-SOD isoform was revealed, while specific POD isoforms were detected in the leaves and stems treated with NaCl or KCl. However, catalase activity was depressed in the salt-treated leaves. At the ultrastructural level, the NaCl-treated leaves had the thickest lamina, due to an extensive increase of the size of epidermal and mesophyll cells. Also, an increase of the relative volume of the intercellular spaces in response to NaCl was observed. The results suggest that Na accumulation is the first candidate for the distinct antioxidant and anatomical responses between saline and osmotically generated stress in the MM 106 explants.

Sugar alcohols-induced oxidative metabolism in cotton callus culture

“…The osmolyteinduced enhancement of POD activity in Coker 312 callus culture indicated that it had a higher capacity for the decomposition of H 2 O 2 generated by SOD. Similar trend was found by Meloni et al (2003) in cotton, Molassiotis et al (2006) in apple, Panda (2001) in green gram and Koji et al (2009) in rice leaves during their studies on salinity.…”

“…cotton (Gossett et al, 1994;Rajguru et al, 1999), mulberry (Harinasut et al, 2003), C. arietinum (Kukreja et al, 2005) and L. esculentum (Gapińska et al, 2008) have also been documented. Furthermore, Molassiotis et al (2006) found that osmotica and salts stresses up-regulated the SOD activity in apple cultivar (MM 106) grown in vitro. Here in case of our findings, such increase is probably the indication of the ability of cotton cells to respond to these stress causing agents.…”

Responses of the cherry rootstock to salinity in vitro

“…Therefore, the assessment of the existing and/or newly developed germplasm of crop plants for their tolerance to salinity has become urgent. In vitro assays is an ideal system for characterizing the genetic potential of tested woody plants as it can be carried out under controlled conditions with limited space and time (Vijayan et al 2003, Molassiotis et al 2006. Such systems can provide reasonable information concerning physiological and biochemical responses of woody species, especially if the in vitro induced response mimics the in vivo plant response exposed to similar salinity (Vijayan et al 2003).…”

Influence of Water Deficit on Iron and Zinc Uptake by Matricaria chamomilla L.

“…Over the past decade, the increased use of irrigation water and the concern over groundwater resources has brought about awareness to efficiently use water resources (Chai et al, 2005;Molassiotis et al, 2006). In dryland cropping systems, improving water use efficiency is an important goal for crop management and improvement.…”

“…By reducing root growth, zinc deficiency can limit the crop's ability to use soil moisture reserves (Nable and Webb, 1993), but the effect of Zn nutrition on the water stress response and plant water relationships has received little attention (Khan et al, 2004). Molassiotis et al (2006) have reported Fe decrease in response to water stress. However, water deficit did not significantly influence Zn content in cherry rootstock Gisela (Sivritepe et al, 2008).…”