Physiological Determination of Reactions Formed by Different Boric Acid Applications in Some Safflower (Carthamus tinctorius L.) Types

Abstract

Introduction: The changes that occur in biotic and abiotic factors cause some changes which are expressed as stress and which are effective on the physiological and metabolic events in plants. These changes may negatively affect growth and development and cause to the death of the plant. In plants, boron stress increases the activities of antioxidative enzymes and causes some physiological changes. In this study safflower (Carthamus tinctorius L.) plant were used as experimental material both as it is an industrial plant that can be used in many fields such as food, forage and dyeing industry and both it shows more resistance to most plants. Material and Methods: In this study, Remzibey, Balcı and Dinçer types of safflower (Carthamus tinctorius L.) plant were used as experimental material. Seeds of each varieties were germinated in seed beds which contains 100 seeds in vials. Distilled water used as control group and 5, 10, 15, 20 mM boric acid (H3BO3) solutions were applied. The condition was 16 hours light/8 hours dark photoperiod and 25±1°C in growth chamber. Changes in APX, CAT, GR and SOD enzyme activities were determined at the physiological level by using leaves of safflower plant which were germinated by applying boric acid in different concentrations. Results: In our study, the values obtained for antioxidative enzyme activity also decreased on high concantration of boric acid. Antioxidant enzyme activities were found to be effective on boron tolerance. It was determined that increase in boric acid concentration increases enzyme activity in all varieties. APX, CAT, GR and SOD activities decreased at 5 and 10 mM and 15 and 20 mM boric acid application was observed relative to other concentrations. Discussion: One of the most important stress factors affecting plants is boron toxicity. Though the element boron is one of the micro elements absolutely necessary for the growing of the plants, too much boron found in the soil is a stress factor which limits the plant growth and productivity. As a result, it is understood from the results of the antioksidant enzime activities that safflower types can cope with the low boric acid concantration. However, high boric acid concantrations (15 and 20 mM) caused to stress and it was determined that increased enzyme activities in plant samples.