Bor Toksisitesine Yanıt Olarak Bor Toleranslı Triticum Dicoccoides Genotipinin Gen Ekspresyon Analizi
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Dosyalar
Tarih
2023
Yazarlar
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Yayıncı
Selçuk Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Biyotik ve abiyotik stres faktörleri ülkemizde ve tüm dünyada tarımsal verimi olumsuz etkilemektedir. Önemli abiyotik stres faktörlerinden biri olan bor toksisitesi, Türkiye dahil dünyanın kurak ve yarı kurak bölgelerinde ciddi bir sorundur. Buğdayın bor toksisitesine duyarlı olduğu ve üretiminin de bor toksisitesinden önemli ölçüde etkilendiği bilinmektedir. Bu nedenle, bor toksik ortamlarda başarıyla yetiştirilebilen, bor toleransı yüksek buğday çeşitlerinin geliştirilmesi gerekmektedir. Bununla birlikte, yoğun buğday ıslah programları, yetiştirilen buğday popülasyonlarında homojenliği geliştirmiş ve onları yüksek bor dahil çevresel streslere karşı daha duyarlı hale getirmiştir. Bu nedenle, daha iyi sürdürülebilirlik için modern buğday genotiplerinin bor toleranslı yeni çeşitlerle değiştirilmesi gerekmektedir. Bor toleranslı yeni buğday genotiplerinin geliştirilmesi için bor toksisite toleransı yüksek buğday genetik kaynaklarının tespit edilmesi ve kullanılması gerekmektedir. Buğday genetik kaynakları geniş bir genetik tabana sahip olup, biyotik ve abiyotik stres koşullarına dayanıklı genotiplerin geliştirilmesi için önemli bir potansiyele sahiptir. Yabani türlerde farklı stres toleranslarında yer alan moleküler mekanizmayı belirlemek ve bunu ekili tahıl mahsullerine uygulamak, adaptif bir strateji olabilir. Buğday genetik kaynakları arasında yabani Gernik buğdayı (Triticum dicoccoides) binlerce yıldır olumsuz koşullara maruz kalmış ve günümüze kadar gelmiştir. Yabani Gernik buğdayı, tarımsal ekonomik değere sahip olmasa da, çevreye uyum ve farklı stres koşullarına tolerans için önemli olan genleri içerir. Modern buğday çeşitlerinin öncüsüdür ve buğdayın atası olduğu için bu özelliklerini buğday ıslahında kullanmak faydalı ve kolay olacaktır. Pek çok stres koşuluna toleranslı genlerin kaynağı olmasına rağmen, T. dicoccoides genotipleri, Bor toksisite toleransı açısından kapsamlı bir şekilde taranmamıştır. Ne bora toleranslı yabani Gernik buğdayı genotipi daha önce bildirilmiş ne de genlerinin yüksek bor altında diferansiyel ekspresyonu çalışılmıştır. Bu amaç doğrultusunda, bu tez kapsamında, Bor toksik koşullarında yetiştirilen bor toleranslı bir T. dicoccoides genotipi olan PI362036'nın diferansiyel olarak eksprese edilen genleri, RNA Dizileme ve RT-qPCR tabanlı ekspresyon analizi ile tanımlanmıştır. Çalışmamızda, T. dicoccoides, PI362036 genotipinin Bor-toksisite toleransı düzeyi, B-toksisite toleransı iyi bilinen bir genotip olan kontrol çeşidi Bolal 2973 ile karşılaştırılarak belirlenmiştir. T. dicoccoides, PI362036'da yüksek bor uygulaması altında sadece yapraklarda daha az sararma gözlenmemiş, aynı zamanda kök uzunluğu dışındaki tüm büyüme parametreleri Bolal 2973'e kıyasla yüksek bor'dan daha az etkilenmiştir. RNA dizileme sonuçlarında toplam 2663 yeni gen ve 9.869 yeni transkript tanımlanmıştır. PI362036'nın gövdelerinde yüksek bor altında toplam olarak 2783 gen önemli ölçüde diferansiyel olarak ifade edilmiştir. Önemli ölçüde düzenlenen bu genlerden 134'ünün aşağı regüle edildiği, 2649 genin ise yukarı regüle edildiği bulunmuştur. Bunlardan, transkriptom sıralama sonuçlarına dayalı olarak RT-qPCR analizi için önemli ölçüde diferansiyel olarak eksprese edilen 8 gen seçilmiştir. Çalışılan sekiz gen arasında Kontrol ile karşılaştırıldığında α-DOX, NAS, GELPs, FTSH 9, DCAF13, ILK1 ve UXS1 genleri yukarı regülasyon gösterirken, SFR1 geni bor toksik büyüme koşulu altında aşağı regülasyon göstermiştir. RT-qPCR ve RNA dizileme deki tüm genlerin diferansiyel ekspresyonu birbiriyle uyumluydu. T. dicoccoides genotipinin yüksek B toleransına ilişkin ilk transkriptomik çalışma olduğundan, elde edilen sonuçlara odaklanılmalı ve yüksek bor'a tolerans sağlamadaki gen fonksiyonunu aydınlatmak için potansiyel aday genlerin fonksiyonel karakterizasyonu yapılmalıdır.
Biotic and abiotic stress factors negatively affect agricultural yield in our country and the entire world. Boron toxicity, which is one of the important abiotic stress factors, is a serious problem in arid and semi-arid regions of the world, including Turkey. It is known that wheat, is sensitive to boron toxicity and its production is also significantly affected by boron toxicity. Therefore, it is necessary to develop high boron tolerant wheat varieties that can be successfully grown in boron toxic environments. However, intensive wheat breeding programs have developed homogeneity in the grown wheat populations and have made them more susceptible to environmental stresses, including high boron. Therefore, it is necessary to replace cultivated wheat genotypes with new boron tolerant varieties for better sustainability. For the development of new boron tolerant wheat genotypes, it is necessary to identify and use wheat genetic resources with high boron toxicity tolerance. Wheat genetic resources have a wide genetic base and have an important potential for the development of genotypes resistant to biotic and abiotic stress conditions. Identifying the molecular mechanism involved in different stress tolerances in wild species and applying it to cultivated cereal crops can be an adaptive strategy. Among the wheat genetic resources, wild emmer wheat (Triticum dicoccoides) has been exposed to adverse conditions for thousands of years and has survived to the present day. Although wild emmer wheat have no agricultural economic value, they contain genes that are important for adaptation to the environment and tolerance to different stress conditions. It is the precursor to modern wheat varieties, and since it is the wheat ancestor, it will be useful and easy to use these features in wheat breeding. Despite being the source of tolerant genes for many stress conditions, T. dicoccoides genotypes have not been thoroughly screened for boron toxicity tolerance. Neither boron tolerant wild emmer wheat genotype has been previously reported nor differential expression of its genes under high boron has been studied. Aiming this issue, within the scope of this thesis, differentially expressed genes of a boron tolerant T. dicoccoides genotype, PI362036 grown under boron toxic condition have been identified via RNA Sequencing and the RT-qPCR based expression analysis. In our study, Boron-toxicity tolerance level of T. dicoccoides, PI362036 genotype was determined by comparing with the check cultivar Bolal 2973, which is a well-known B-toxicity-tolerant genotype. Not only less yellowing of the leaves was observed in T. dicoccoides, PI362036 under high-Boron treatment, but also all the growth parameters, other than root length were less influenced by high boron as compared to Bolal 2973. In RNA sequencing results, total 2663 novel genes and 9,869 novel transcripts were identified. A total of 2783 genes were significantly differentially expressed in the shoots of PI362036 under high boron. Out of these significantly regulated genes, 134 were found to be downregulated, while 2649 genes were up-regulated. Among these, 8 significantly differentially expressed genes were selected for RT-qPCR analysis based on transcriptome sequencing results. Among the studied eight genes, while α-DOX, NAS, GELPs, FTSH 9, DCAF13, ILK1, and UXS1 genes showed an upregulation, SFR1 gene showed downregulation under boron toxic growth condition as compared to Control. The differential expression of all the genes in RT-qPCR and RNA sequencing was in accordance with each other. Being the first transcriptomic study on the high boron tolerance of the T. dicoccoides genotype, the obtained results should be focused, and the functional characterization of potential candidate genes should be conducted to elucidate the gene function in providing tolerance to high boron.
Biotic and abiotic stress factors negatively affect agricultural yield in our country and the entire world. Boron toxicity, which is one of the important abiotic stress factors, is a serious problem in arid and semi-arid regions of the world, including Turkey. It is known that wheat, is sensitive to boron toxicity and its production is also significantly affected by boron toxicity. Therefore, it is necessary to develop high boron tolerant wheat varieties that can be successfully grown in boron toxic environments. However, intensive wheat breeding programs have developed homogeneity in the grown wheat populations and have made them more susceptible to environmental stresses, including high boron. Therefore, it is necessary to replace cultivated wheat genotypes with new boron tolerant varieties for better sustainability. For the development of new boron tolerant wheat genotypes, it is necessary to identify and use wheat genetic resources with high boron toxicity tolerance. Wheat genetic resources have a wide genetic base and have an important potential for the development of genotypes resistant to biotic and abiotic stress conditions. Identifying the molecular mechanism involved in different stress tolerances in wild species and applying it to cultivated cereal crops can be an adaptive strategy. Among the wheat genetic resources, wild emmer wheat (Triticum dicoccoides) has been exposed to adverse conditions for thousands of years and has survived to the present day. Although wild emmer wheat have no agricultural economic value, they contain genes that are important for adaptation to the environment and tolerance to different stress conditions. It is the precursor to modern wheat varieties, and since it is the wheat ancestor, it will be useful and easy to use these features in wheat breeding. Despite being the source of tolerant genes for many stress conditions, T. dicoccoides genotypes have not been thoroughly screened for boron toxicity tolerance. Neither boron tolerant wild emmer wheat genotype has been previously reported nor differential expression of its genes under high boron has been studied. Aiming this issue, within the scope of this thesis, differentially expressed genes of a boron tolerant T. dicoccoides genotype, PI362036 grown under boron toxic condition have been identified via RNA Sequencing and the RT-qPCR based expression analysis. In our study, Boron-toxicity tolerance level of T. dicoccoides, PI362036 genotype was determined by comparing with the check cultivar Bolal 2973, which is a well-known B-toxicity-tolerant genotype. Not only less yellowing of the leaves was observed in T. dicoccoides, PI362036 under high-Boron treatment, but also all the growth parameters, other than root length were less influenced by high boron as compared to Bolal 2973. In RNA sequencing results, total 2663 novel genes and 9,869 novel transcripts were identified. A total of 2783 genes were significantly differentially expressed in the shoots of PI362036 under high boron. Out of these significantly regulated genes, 134 were found to be downregulated, while 2649 genes were up-regulated. Among these, 8 significantly differentially expressed genes were selected for RT-qPCR analysis based on transcriptome sequencing results. Among the studied eight genes, while α-DOX, NAS, GELPs, FTSH 9, DCAF13, ILK1, and UXS1 genes showed an upregulation, SFR1 gene showed downregulation under boron toxic growth condition as compared to Control. The differential expression of all the genes in RT-qPCR and RNA sequencing was in accordance with each other. Being the first transcriptomic study on the high boron tolerance of the T. dicoccoides genotype, the obtained results should be focused, and the functional characterization of potential candidate genes should be conducted to elucidate the gene function in providing tolerance to high boron.
Açıklama
Anahtar Kelimeler
Abiyotik Stres, Bor Toksisitesi, Buğday, Gen Ekspresyonu, RNA Sekanslaması, RT-qPCR, T. Dicoccoides, Abiotic Stress, Boron Toxicity, Gene Expression, RNA Sequencing, Wheat
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Şen, B., (2023). Bor Toksisitesine Yanıt Olarak Bor Toleranslı Triticum Dicoccoides Genotipinin Gen Ekspresyon Analizi. (Yüksek Lisans Tezi). Selçuk Üniversitesi, Fen Bilimleri Enstitüsü, Konya.
