Olea europaea L. yaprağından CBF1 transkripsiyon faktörü homoloğunu kodlayan tam uzunluktaki genin klonlanması

One of the most prevalent environmental stresses that affects plants physically and physiologically is the low temperature. Since low temperature adversely affects plant productivity Researchers investigated the molecular processes that regulate the effects of cold stress on plants and discovered many cold responsive genes as well as the control mechanisms that regulate them. CBF/DREB (C repeat binding factor/dehydration response element binding factor) transcription factors induces the expression of corresponding genes in plants in response to abiotic stress conditions such as cold, drought and salinity. These transcription factors contribute to plant resistance to stress by activating genes in various pathways. Genes encoding CBF transcription factors were first discovered in Arabidopsis thaliana (L.). Later, Gene homologs were isolated and cloned from a variety of plants. They belong to the AP2/EREBP protein family. In the present study, the full-length cDNA encoding homologue of the transcription factor CBF1 was cloned from Olea europaea L. cv. Gemlik leaves. A 748 bp long cDNA encodes a hypothetical protein of 224 amino acids. BLAST analysis revealed that the CBF1 sequences of Gemlik cultivar and wild olive were nearly identical. A phylogenetic tree was built using Olea europea L. cv. Gemlik CBF1 sequence.Bitkileri fiziksel ve fizyolojik olarak etkileyen en yaygın çevresel streslerden biri düşük sıcaklıktır. Düşük sıcaklık bitki verimliliğini olumsuz etkilediğinden, araştırmacılar soğuk stresinin bitkiler üzerindeki etkilerini düzenleyen moleküler süreçleri araştırmışlar ve soğuğa duyarlı genlerle birlikte bunların kontrol mekanizmalarını da ortaya çıkarmışlardır. CBF/DREB (C tekrar bağlama faktörü/dehidrasyon yanıt elemanı bağlama faktörü) transkripsiyon faktörleri, bitkilerde soğuk, kuraklık ve tuzluluk gibi abiyotik stres koşullarına yanıt olarak ifade edilen genlerin ekspresyonunu indüklemektedir. Bu transkripsiyon faktörleri, çeşitli yolaklardaki genleri aktive ederek strese karşı bitki direncine katkıda bulunurlar. CBF transkripsiyon faktörlerini kodlayan genler ilk olarak Arabidopsis thaliana'da (L.) keşfedildi. Daha sonra çeşitli bitkilerden gen homologları klonlandı. CBF/DREB transkripsiyon faktörleri AP2/EREBP protein ailesi içinde yer alırlar. Bu çalışmada, transkripsiyon faktörü CBF1'in homologunu kodlayan tam uzunluktaki cDNA, Olea europaea L. cv. Gemlik yapraklarından klonlanmıştır. 748 bp uzunluğunda cDNA, 224 amino asitlik varsayımsal bir proteini kodlar. BLAST analizi, Gemlik çeşidinin ve yabani zeytinin CBF1 dizilerinin neredeyse aynı olduğunu ortaya çıkardı. Olea europea L. cv Gemlik CBF1 dizisi kullanılarak bir filogenetik ağaç oluşturuldu

Generation and Analysis of Expressed Sequence Tags from Olea europaea L.

Olive (Olea europaea L.) is an important source of edible oil which was originated in Near-East region. In this study, two cDNA libraries were constructed from young olive leaves and immature olive fruits for generation of ESTs to discover the novel genes and search the function of unknown genes of olive. The randomly selected 3840 colonies were sequenced for EST collection from both libraries. Readable 2228 sequences for olive leaf and 1506 sequences for olive fruit were assembled into 205 and 69 contigs, respectively, whereas 2478 were singletons. Putative functions of all 2752 differentially expressed unique sequences were designated by gene homology based on BLAST and annotated using BLAST2GO. While 1339 ESTs show no homology to the database, 2024 ESTs have homology (under 80%) with hypothetical proteins, putative proteins, expressed proteins, and unknown proteins in NCBI-GenBank. 635 EST's unique genes sequence have been identified by over 80% homology to known function in other species which were not previously described in Olea family. Only 3.1% of total EST's was shown similarity with olive database existing in NCBI. This generated EST's data and consensus sequences were submitted to NCBI as valuable source for functional genome studies of olive

The Fission Yeast HIRA Histone Chaperone Is Required for Promoter Silencing and the Suppression of Cryptic Antisense Transcripts▿ †

The assembly of nucleosomes by histone chaperones is an important component of transcriptional regulation. Here, we have assessed the global roles of the HIRA histone chaperone in Schizosaccharomyces pombe. Microarray analysis indicates that inactivation of the HIRA complex results in increased expression of at least 4% of fission yeast genes. HIRA-regulated genes overlap with those which are normally repressed in vegetatively growing cells, such as targets of the Clr6 histone deacetylase and silenced genes located in subtelomeric regions. HIRA is also required for silencing of all 13 intact copies of the Tf2 long terminal repeat (LTR) retrotransposon. However, the role of HIRA is not restricted to bona fide promoters, because HIRA also suppresses noncoding transcripts from solo LTR elements and spurious antisense transcripts from cryptic promoters associated with transcribed regions. Furthermore, the HIRA complex is essential in the absence of the quality control provided by nuclear exosome-mediated degradation of illegitimate transcripts. This suggests that HIRA restricts genomic accessibility, and consistent with this, the chromosomes of cells lacking HIRA are more susceptible to genotoxic agents that cause double-strand breaks. Thus, the HIRA histone chaperone is required to maintain the protective functions of chromatin