Surhay Ragimoğlu ALLAHVERDIEV, Rena GANİEVA, Saeedeh NAFISI, Meltem MAVİTUNA

Effects of salt stress and synthetic hormone polystimuline K on photosynhetic activity of Trianea bogotensis Karst

Bu çalışmada kinetin benzeri sentetik hormon olan Polystimulin K (PS-K)'nin tuz stresi uygulanmış Trianea bogotensis Karst'ın (Hydrocharitaceae) fotosentetik aktivitesi üzerine etkisi gösterildi. Değişik zaman sürelerinde (15, 30, 60, 360 ve 720 dakika) farklı tuz stresi (103, 155 ve 344 mM) uygulanmaları sonucunda , Fotosistem II (FS ll)'nin hassasiyetini incelemek için Klorofil değişken Floresans (Chlorophyll variable fluorescence) (Fv) ve yavaş floresans (Slow Fluorescence) (SF) kullanıldı. Fideler üzerindeki tuz (155 mM NaCl) uygulaması SF boyutunu yaklaşık % 50 engelledi. Fidelerin 30 dakika süreyle 20 mg/l PS-K uygulamasına tabi tutulması ve daha sonra tuz ortamına alınması sonucunda SF boyutunun yükselmesi saptanmıştır. Tuz stresi altında, bütün zaman süreçlerinde, Fv/Fo oranı azalma göstermektedir. Uygulamaların 60 dakika'sına kadar NaCl ve PS-K'nin bulunduğu ortamda Fv/Fo miktarı bir düşüş gösterip, daha sonra hafif bir yükseliş tespit edildi. Bu çalışmanın sonuçları PS-K'nin tuz stresi mekanizmasındaki koruyucu görevini anlamak açısından önemlidir.

Tuz stresi ve polistimulin K adlı sentetik hormon'un Trianea bogotensis Karst'ın fotosentetik aktivetesi üzerine etkileri

In the present study the effect of kinetin like synthetic hormone Polystimuline K (PS-K) on photosynthetic activity of salt stressed Trianea bogotensis Karst (Hydrocharitaceae) has been shown. Chlorophyll variable fluorescence (Fv) and slow fluo¬rescence (SF) have been used to investigate the sensitivity of Photosystem 11 (PS II) to different salt stress treatments (103, 155 and 344 mM), at different time courses (15, 30, 60, 360 and 720 minutes). Salt stress (155 mM NaCl) treatments of the seed¬lings inhibited the SF magnitude approximately to 50 %. Pretreatment of seedlings for 30 minutes in 20 mg/l PS-K followed by salt stress resulted in an increase in SF magnitude. Under salt stress the magnitude of Fv/Fo decreases within all time measurments. In the presence of NaCl and PS-K until 60 min. of treatment there was a decrease in Fv/Fo value, then a slight increase was ob¬served. The results of this study are important in understanding the protective function of PS-K on salt stress mechanism.

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