Responses of Spinacia oleracea L. cv. Matador Plants to Various Abiotic Stresses Such as Cadmium Metal Toxicity, Drought and Salinity

Abstract

Spinacia oleracea L. cv. Matador plants produced in many regions are exposed to many abiotic stresses from drought to metal toxicity. In this study, the effects of drought (control: 100% field capacity (FC), D1: 50% FC and D2: no-watering), salinity (100 and 200 mM NaCl) and cadmium (Cd; 100 and 200 µM CdCl2) metal toxicity, which are among the most common abiotic stress factors, on spinach plants were determined at the cellular level. There was not determined any alterations along 10 days’ drought, salinity and Cd stress in dry and fresh weights of spinach plants grown in plant growth chamber, in which there is a 16-hour photoperiod under a light intensity of 1200 lux at 24°C/20°C (day/night). However, all treatments caused oxidative stress. Cd treatments were more structurally damaging than drought and salinity treatments. In drought and salinity treatments, chlorophyll content and dry weight did not change despite the increased superoxide dismutase (SOD) and catalase (CAT) activities. The highest values in SOD activity were obtained at D2-drought treatment and 200 mM salinity treatment. SOD activity determined in Cd treatments was also increased compared to control, but this increase was lower than the other treatments. Thus, it can be considered that CAT enzyme is primarily scavenger of reactive oxygen species (ROS) in spinach plants under Cd stress. As a results, spinach plants had an ability to cope with this stresses. The different responses of spinach seedlings to various stress factors provide for estimate of the plant's powerful physiological mechanism. In the continuation of this study, it is recommended to conduct molecular studies and to investigate of the cellular responses to long-term stress on Spinacia oleracea L. cv. Matador plants, which we found to be tolerant to short-term stresses.