Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Article Citation - WoS: 14Citation - Scopus: 16Transcriptomic Analysis of Boron Hyperaccumulation Mechanisms in Puccinellia Distans(Elsevier Ltd., 2018) Öztürk, Saniye Elvan; Göktay, Mehmet; Has, Canan; Babaoğlu, Mehmet; Allmer, Jens; Doğanlar, Sami; Frary, AnnePuccinellia distans, common alkali grass, is found throughout the world and can survive in soils with boron concentrations that are lethal for other plant species. Indeed, P. distans accumulates very high levels of this element. Despite these interesting features, very little research has been performed to elucidate the boron tolerance mechanism in this species. In this study, P. distans samples were treated for three weeks with normal (0.5 mg L−1) and elevated (500 mg L−1) boron levels in hydroponic solution. Expressed sequence tags (ESTs) derived from shoot tissue were analyzed by RNA sequencing to identify genes up and down-regulated under boron stress. In this way, 3312 differentially expressed transcripts were detected, 67.7% of which were up-regulated and 32.3% of which were down-regulated in boron-treated plants. To partially confirm the RNA sequencing results, 32 randomly selected transcripts were analyzed for their expression levels in boron-treated plants. The results agreed with the expected direction of change (up or down-regulation). A total of 1652 transcripts had homologs in A. thaliana and/or O. sativa and mapped to 1107 different proteins. Functional annotation of these proteins indicated that the boron tolerance and hyperaccumulation mechanisms of P. distans involve many transcriptomic changes including: alterations in the malate pathway, changes in cell wall components that may allow sequestration of excess boron without toxic effects, and increased expression of at least one putative boron transporter and two putative aquaporins. Elucidation of the boron accumulation mechanism is important in developing approaches for bioremediation of boron contaminated soils.Master Thesis Elecidation of Selenium Tolerance Mechanisms in Puccinellia Distans (jacq.) Parl, Using a Transcriptomic Approach(Izmir Institute of Technology, 2018) Kök, Aysu Başak; Frary, Anne; Eroğlu, SeçkinSelenium (Se) has a versatile chemistry. Therefore, it is present in a wide variety of materials on Earth. Although it is not an essential element for plants, Se provides several survival and ecological advantages. Puccinellia distans (P.distans) is weeping alkali grass which has a relatively fast growth rate and produces a large biomass. It can also hyperaccumulate extreme concentrations of boron and tolerate high levels of salinity. It is known that some plant species can tolerate high concentrations of soil salts and boron while hyperaccumulating Se in their leaves. Therefore, in this study, the Se accumulation and tolerance capacity of P. distans were investigated, and the plant’s Se tolerance mechanism was elucidated using a transcriptomic approach. The results of this study indicated that P. distans accumulated more than 100 mg Se kg-1 in its shoots. Therefore, P. distans was discovered to be a novel Se accumulator plant. Biochemical analyses and RNA sequencing results helped us to decipher the Se tolerance and accumulation mechanism of P. distans. Accordingly, the tolerance mechanism was found to be associated with the upregulation of genes involved in sulfate, selenocompound and antioxidant pathways. Here, we suggest that upregulation of Se assimilation and stress responses genes may have been due to induction of jasmonic acid signaling. In addition, we propose that the cell wall may play an important role in restriction of Se movement to the cytoplasm. Also, we put forward that sequestration of selenate inside the vacuole may be a way that Se accumulates in cells.