Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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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.Article Citation - WoS: 36Citation - Scopus: 46Expression of Vitreoscilla Hemoglobin in Gordonia Amarae Enhances Biosurfactant Production(Springer Verlag, 2006) Doğan, İlhan; Pagilla, Krishna R.; Webster, Dale A.; Stark, Benjamin C.The gene (vgb) encoding Vitreoscilla (bacterial) hemoglobin (VHb) was electroporated into Gordonia amarae, where it was stably maintained, and expressed at about 4 nmol VHb g -1 of cells. The maximum cell mass (OD 600) of vgb-bearing G. amarae was greater than that of untransformed G. amarae for a variety of media and aeration conditions (2.8-fold under normal aeration and 3.4-fold under limited aeration in rich medium, and 3.5-fold under normal aeration and 3.2-fold under limited aeration in mineral salts medium). The maximum level of trehalose lipid from cultures grown in rich medium plus hexadecane was also increased for the recombinant strain, by 4.0-fold in broth and 1.8-fold in cells under normal aeration and 2.1-fold in broth and 1.4-fold in cells under limited aeration. Maximum overall biosurfactant production was also increased in the engineered strain, by 1.4-fold and 2.4-fold for limited and normal aeration, respectively. The engineered strain may be an improved source for producing purified biosurfactant or an aid to microorganisms bioremediating sparingly soluble contaminants in situ.