Publication: Spermidin uygulamalarının prunus domestica'nın polen performansı üzerine etkileri
Abstract
Bu çalışmanın amacı spermidin uygulamalarının Prunus domestica’nın polen performansına olan etkilerini incelemek ve spermidinin polen tüpü içindeki konsantrasyona bağımlı multifaktöriyel etkilerini açıklığa kavuşturmaktır. Bu amaç doğrultusunda polen taneleri farklı konsantrasyonlarda spermidin içeren (0,01 mM, 0,025 mM, 0,05 mM, 0,1 mM, 0,25 mM, 0,5 mM) polen çimlendirme ortamlarında 1 saat çimlendirilmiştir. Farklı konsantrasyonlarda spermidin uygulamalarının polen performansı üzerindeki etkileri polen çimlenme oranı, polen tüp uzunluğu, polen tüplerinin büyüme salınımı, aktin hücre iskelet organizasyonu, Ca+2, pH ve reaktif oksijen türleri gradienti, sükroz sentaz enzim lokalizasyonu, tüp çeperindeki kalloz, selüloz ve pektin dağılımı ve genaratif nükleusların tüp ucuna taşınma hızına odaklanılarak incelenmiştir.Polen performansını en fazla artıran spermidin konsantrasyonu 0,01 mM olarak belirlenmiştir. Bu grupta reaktif oksijen türleri gradientindeki keskin değişimler polen tüplerindeki aktin hücre iskelet dinamizmini arttırmış, artan aktin hücre iskelet dinamizmi ise sükroz sentaz enzim lokalizasyonunu koordine ederek tüplerin daha hızlı uzamalarını sağlayacak şekilde tüp ucundaki selüloz miktarında azalmaya neden olmuştur. Polen performansını en fazla azaltan spermidin konsantrasyonu ise 0,5 mM olarak belirlenmiştir. Bu grupta Ca+2, pH ve reaktif oksijen türleri gradientindeki keskin değişimler polen tüplerindeki aktin hücre iskelet dinamizmini azaltmış, azalan aktin hücre iskelet dinamizmi ise yeni sentezlenen çeper maddelerinin tüp ucuna taşınmasına ket vurarak polen tüplerinin uzamasına engel olmuştur. Ayrıca 0,5 mM spermidin uygulaması sükroz sentaz enzim lokalizasyonunu etkilenmiş ve bu etki tüp çeperine kalloz birikim anormallikleri olarak yansımıştır. 0,5 mM spermidin uygulaması generatif nükleusun tüp ucuna taşınmasına ket vursa da generatif nükleusta herhangi bir hasara yol açmamıştır. Bu tez çalışmasından elde edilen bulguların poliaminlerin polen çimlenmesi ve tüp uzaması üzerindeki rollerinin daha iyi anlaşılmasına ve spermidinin polen tüplerindeki etki mekanizmasının aydınlatılmasına katkı sağlayacağı düşünülmektedir.
The aim of this study is to examine the effects of spermidine treatments on the pollen performance of Prunus domestica and to clarify the concentration-dependent multifactorial effects of spermidine in the pollen tube. For this purpose, pollen grains were germinated in pollen germination media containing different concentrations of spermidine (0,01 mM, 0,025 mM, 0,05 mM, 0,1 mM, 0,25 mM, 0,5 mM) for 1 hour. The effects of different spermidine concentrations on pollen performance were investigated, focusing on the pollen germination rate, pollen tube length, growth oscillation of pollen tubes, actin cytoskeleton organization, Ca2+, pH and reactive oxygen species gradient, sucrose synthase enzyme localization, distribution of callose, cellulose, pectin in the cell wall and, the transport rate of generative nuclei to the tube tip. 0,01 mM spermidine was determined as the concentration that increased the pollen performance the most. In this group, acute changes in the reactive oxygen species gradient increased the actin cytoskeleton dynamism in the pollen tubes, while the increased actin cytoskeleton dynamism coordinated the sucrose synthase enzyme localization and caused a decrease in the amount of cellulose at the tube end, allowing the tubes to elongate faster. 0,5 mM spermidine was determined as the concentration that reduced the pollen performance the most. In this group, acute changes in the Ca+2, pH, and reactive oxygen species gradients decreased the actin cytoskeleton dynamism and the reduced actin cytoskeleton dynamism prevented the elongation of the pollen tubes by inhibiting the transport of newly synthesized wall materials to the tube tip. Moreover, 0,5 mM spermidine treatment affected the sucrose synthase enzyme localization and this effect was reflected as callose accumulation abnormalities on the tube wall. Although 0,5 mM spermidine treatment inhibited the transport of the generative nucleus to the tube tip, it did not cause any damage to the generative nucleus. It is thought that the obtained results from this thesis will contribute to a better understanding of the polyamines' roles in pollen germination and tube elongation and elucidate the action mechanism of spermidine in pollen tubes.
The aim of this study is to examine the effects of spermidine treatments on the pollen performance of Prunus domestica and to clarify the concentration-dependent multifactorial effects of spermidine in the pollen tube. For this purpose, pollen grains were germinated in pollen germination media containing different concentrations of spermidine (0,01 mM, 0,025 mM, 0,05 mM, 0,1 mM, 0,25 mM, 0,5 mM) for 1 hour. The effects of different spermidine concentrations on pollen performance were investigated, focusing on the pollen germination rate, pollen tube length, growth oscillation of pollen tubes, actin cytoskeleton organization, Ca2+, pH and reactive oxygen species gradient, sucrose synthase enzyme localization, distribution of callose, cellulose, pectin in the cell wall and, the transport rate of generative nuclei to the tube tip. 0,01 mM spermidine was determined as the concentration that increased the pollen performance the most. In this group, acute changes in the reactive oxygen species gradient increased the actin cytoskeleton dynamism in the pollen tubes, while the increased actin cytoskeleton dynamism coordinated the sucrose synthase enzyme localization and caused a decrease in the amount of cellulose at the tube end, allowing the tubes to elongate faster. 0,5 mM spermidine was determined as the concentration that reduced the pollen performance the most. In this group, acute changes in the Ca+2, pH, and reactive oxygen species gradients decreased the actin cytoskeleton dynamism and the reduced actin cytoskeleton dynamism prevented the elongation of the pollen tubes by inhibiting the transport of newly synthesized wall materials to the tube tip. Moreover, 0,5 mM spermidine treatment affected the sucrose synthase enzyme localization and this effect was reflected as callose accumulation abnormalities on the tube wall. Although 0,5 mM spermidine treatment inhibited the transport of the generative nucleus to the tube tip, it did not cause any damage to the generative nucleus. It is thought that the obtained results from this thesis will contribute to a better understanding of the polyamines' roles in pollen germination and tube elongation and elucidate the action mechanism of spermidine in pollen tubes.