Effect of drought stress on oxidative damage and antioxidant enzyme activity in melon seedlings

Abstract

IntroductionMelon (Cucumis melo L.), an annual diploid plant, is an economically important horticultural crop grown in temperate, subtropical, and tropical regions worldwide. With a total production of 1.7 million tons, Turkey was the second biggest producer after China in 2009. Like many other fruits melon fruits provide a good source of potassium and vitamin C. They are also fat and cholesterol free, high in water content, and are relatively low in calories. Moreover, melons may have an anticlotting action and are also thought to lower cancer and heart disease risk (Lester, 1996).Biotic and abiotic stresses are the most important factors that severely limit plant growth and metabolism (Makbul et al., 2011). Abiotic stress is the primary cause of crop loss worldwide, reducing average yields for most major crop plants by more than 50% (Bray et al., 2000). Moreover, when the usable areas on the earth are classified in view of stress factors, drought stress is one of the most widespread environmental stresses (Arora et al., 2002;Saruhan Güler et al., 2012). Although each stress factor produces its own specific effect on plants, in general all stress conditions can cause an increase in reactive oxygen species (ROS). ROS are recognized as detrimental to biological systems because they cause the oxidation of lipids, proteins, deoxyribonucleic acid, and carbohydrates. Ultimately, toxic levels of ROS cause a chain reaction of cellular oxidation, which results in unhealthy situations and lethality. In addition to the oxidative stress related production, ROS are an inevitable outcome of normal physiological processes, such as glycolysis and photosynthesis (Mittler et al., 2004). Plant antioxidant systems, both enzymatic and nonenzymatic, play an important role in balancing and preventing oxidative damage (Foyer et al., 1994;Baysal Furtana and Tıpırdamaz, 2010). Nonenzymatic antioxidant metabolites include anthocyanin, flavonoids, carotenoids, α-tocopherol, ascorbate (AsA), and reduced glutathione (GSH) (Halliwell, 1987); enzymatic antioxidants consist of superoxide dismutase (

Effects of gradual soil drought stress on the growth, biomass partitioning, and chlorophyll fluorescence of Prunus mongolica seedlings

“…However, soil water content less than or equal to 11.38% adversely affected the growth and survival of P. mongolica (Figures 1a-1d). Leaf RWC is a reliable and common indicator for defining the sensitivity of plants to dehydration (Rampino et al, 2006;Sanchez-Rodriguez et al, 2010;Kavas et al, 2013). In the present study, the leaf RWC in P. mongolica was influenced by the intensity of the stress imposed.…”

“…The relative water content (RWC) of leaves was determined in accordance with the method described by Kavas et al (2013). Five fully expanded leaves at the mid-canopy position were collected per seedling after 0, 7, 14, 21, 28, 35, and 42 days.…”

Ploidy stability of Oryza sativa. L cv IR64 transformed with the moth bean P5CS gene with significant tolerance against drought and salinity

“…Lower lipid peroxidation levels and enhanced salt tolerance of P5CS in transgenic KJT-3 has also been reported (Kumar et al, 2010). Proline-mediated osmoregulation plays a vital role in protection mechanism against drought stress in melons (Kavas et al, 2013). P5CS-led proline production enhanced survival and the growth of transformants compared with the nontransformants.…”

Germination and antioxidant action in melon seeds exposed to salt stress

“…The differences observed in the antioxidant enzymes activities, considering the different osmotic potentials and imbibition times, indicate various factors that interfere with the activity of these enzymes or favor it, such as the osmotic and/or toxic effects caused by excessive salt concentrations and the balance between the levels of reactive oxygen species and the antioxidant systems, in the prevention of cell oxidative stress (Sivritepe et al 2008, Kavas et al 2013.…”