ARPA ve BUĞDAY ÇEŞİTLERİNDE AĞIR METAL UYGULAMALARININ ANTİOKSİDAN SAVUNMA AKTİVASYONU ÜZERİNE ETKİLERİ

Ağır metaller, reaktif oksijen türlerinin oluşumuyla oksidatif stres için ajanlar olarak bilinir ve yeryüzünde birikir. Bu birikim daha sonra besin zinciri yoluyla insanlara taşınabilir ve daha ciddi sağlık sorunlarına neden olur. Çok hücreli yüksek organizmalar olarak bitkiler, bu trafik sırasında ağır metal birikiminin ilk durağıdır. Bu nedenle, bitkiler sadece bu ulaşımın aracı değil, aynı zamanda düşük üretkenlikleri nedeniyle hayvanlar ve insanlarla birlikte etkilenen diğer organizmalardır. Bununla birlikte, antioksidan savunma sistemleri oksidatif strese karşı çok önemli bir savunma oynadığından, bu tepkiler bitkilerde ağır metal toksisitesinin erken biyobelirteçleri olarak kullanılabilir. Buna dayanarak, bu çalışmada farklı kültür bitkilerinde antioksidan savunma tepkilerinin ağır metal kadmiyum ve kurşunun toksisitesi için güvenilir indikatörler olup olmadığını inceledik. Hordeum vulgare cv. Çıldır ve Triticum aestivum cv. Gerek tohumları kullanılarak, bahsedilen çeşitlerin kök ve sürgünlerinde glutatyon (GSH), protein içerikleri ve glutatyon S-transferaz (GST) aktivitelerini araştırmak için farklı tek ve kombine CdCl2 ve PbCl2 konsantrasyonları uygulanmıştır. Sonuçlarımız, ağır metallerin test edilen parametreler üzerinde etkili olduğunu ve sonuçlardaki değişkenliğin çeşitler arasında ağır metallere göre metabolizma hızındaki farklılıkları yansıttığını göstermiştir. Öte yandan, incelenen bitkilerde gözlenen yüksek GSH ve GST değerleri nedeniyle, çalışmada uygulanan ağır metaller açısından genel olarak stres koşullarına uyum sağladıkları belirtilmelidir.

Anahtar Kelimeler:

Ağır metaller, Antioksidan savunma, Arpa, Buğday, Oksidatif stres

THE EFFECTS of HEAVY METAL APPLICATIONS on ANTIOXIDANT DEFENCE ACTIVATION in BARLEY and WHEAT VARIETIES

Heavy metals are known as agents for oxidative stress by formation of reactive oxygen species and accumulated on the earth. This accumulation can than be transported via food chain to humans and causes some more serious health problems. As a multicellular higher organisms, plants are the first stop for heavy metal accumulation during this traffic. Therefore, plants are not only the vehicle of this transportation, but also another affected organisms together with animals and humans, due to their lowered self productivity. However, as antioxidant defence systems play a crucial defence against oxidative stress, these responses could be used as early biomarkers of heavy metal toxicity in plants. Based on this, we have examined whether antioxidant defence responses are reliable indicators for the toxicity of heavy metals cadmium and lead in different crop plants within this study. By using the seeds of Hordeum vulgare cv. Çıldır and Triticum aestivum cv. Gerek, different single and combined concentrations of CdCl2 and PbCl2 treatments were applied to investigate glutathione (GSH), protein contents and glutathione S-transferase (GST) activities in the roots and shoots of these mentioned varieties. Our results shown that, heavy metals had an effect on the tested parameters and variability in results reflect the differences in the rate of metabolism with regard to heavy metals between varieties. On the other hand, due to the high GSH and GST values observed in the studied plants, it should be mentioned that they are generally adaptable to stress conditions with regard to applied heavy metals in the study.

Keywords:

Antioxidant mechanisms, barley, heavy metals, oxidative stress, wheat,

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