Responses of antioxidant enzymes and compounds in strawberry (Fragaria×ananassa‘Toyonaka’) to cold stress

Abstract

The aim of this study was to investigate the responses of the antioxidative system of strawberry (Fragaria × ananassa 'Toyonaka') to cold stress. Strawberry seedlings were exposed to four temperatures (25°C or control, 10°C, 4°C, and 0°C) and the compounds and enzyme activities were determined during six evaluation periods (0, 6, 12, 24, 48, and 72 h). Malondialdehyde (MDA) and h 2 O 2 concentrations fluctuated and increased overall at lower temperatures. The production rate of superoxide radical (O 2 -) increased continuously with all treatments. Cold stress increased antioxidant enzyme activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (gR), dehydroascorbate reductase (DhAR), and monodehydroascorbate reductase (MDAR), when compared with the control. Ascorbate (AsA) content reduced, however dehydroascorbate (DhA) showed a significant increase, as did the ASA/ DhA ratio. The results suggest that the ascorbateglutathione cycle is regulated in response to low temperature, but this mechanism and consequently regulation ability peaks and declines with exposure to cold stress.

Influence of long-term cold stress on enzymatic antioxidative defense system in chickpea (Cicer arietinum L.)

“…This obviously shows that oxidative stress has occurred at low temperatures, which is possibly due to the overaccumulation of ROS. Some similar results have also been reported by other workers [26,32,40,41]. In some cases, the MDA content was diminished and this drop was possibly caused by increasing CAT, SOD, APX, or GPX activities.…”

“…In the present study, the higher H 2 O 2 levels in the leaves of some chickpea genotypes exposed to low temperatures, in comparison with the unstressed plants, revealed the degree of oxidative stress during severe cold stress. Some similar results have also been reported in the literature [40,41]. High levels of H 2 O 2 , as detected in the severely stressed seedlings of some chickpea genotypes due to its toxicity, can create a signal which triggers the programmed cell death process [44].…”

“…The results of this research demonstrated that cold treatment of chickpea plants results in H 2 O 2 accumulation that may be one of the key factors responsible for the rise in the MDA levels. Conversely, lower H 2 O 2 levels, as found in the medium-stressed seedlings of some chickpea genotypes, possibly play a secondary role in the stress signaling system through prompting defensive pathways [41].…”

Strawberry physiological and biochemical responses to chilling and freezing stress and application of alleviating factors as countermeasures

“…ROS production triggers the counter-measures mechanism of the plant, including the activation of antioxidant enzymes such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione reductase (GR), ascorbate peroxidase (APOX), polyphenol-oxidase (PPO) etc. as well as the production of antioxidant molecules such as ascorbic acid, phenolic compounds etc [3][4][5].…”

“…Under such conditions some plants have evolved mechanisms to withstand water shortage under freezing temperatures. Upon exposure to low, non-freezing, non-lethal suboptimal temperatures, plant starts the synthesis of various molecules, among which cryo-or osmo-protectans have a major role [5]. The so-called compatible solutes are low molecular weight, highly soluble compounds, protecting cell integrity by participating in osmotic adjustment, detoxification of reactive oxygen species, protection of membrane function, and stabilization of enzymes/proteins.…”