Members of basic helix-loop-helix (bHLH) gene family found in all eukaryotes play crucial roles in response to stress. Though, most eukaryotes carry the proteins of this family, biological functions of the most bHLH family members are not deeply evaluated in plants. In this study, we conducted a comprehensive genome-wide analysis of bHLH transcription factors in salt tolerant common bean. We identified 155 bHLH protein-encoding genes (PvbHLH) by using in silico comparative genomics tools. Based on the phylogenetic tree, PvbHLH genes were classified into 8 main groups with 21 subfamilies. Exon-intron analysis indicated that proteins belonging to same main groups exhibited a closely related gene structure. While, the PvbHLH gene family has been mainly expanded through segmental duplications, a total of 11 tandem duplication were detected. Genome-wide expression analysis of bHLH genes showed that 63 PvbHLH genes were differentially expressed in at least one tissue. Three of them displayed higher expression values in both leaf and root tissues. The in silico micro-RNA target transcript analyses revealed that totally 100 PvHLH genes targeted by 86 plant miRNAs. The most abundant transcripts, which were targeted by all 18 plant miRNA, were belonging to PvHLH-22 and PvHLH-44 genes. The expression of 16 PvbHLH genes in the root and leaf tissues of salt-stressed common bean was evaluated using qRT-PCR. Among them, two of PvbHLHs, PvbHLH-54, PvbHLH-148, were found to be up-regulated in both tissues in correlation with RNA-seq measurements. The results of this study could help improve understanding of biological functions of common bean bHLH family under salt stress. Additionally, it may provide basic resources for analyzing bHLH protein function for improving economic, agronomic and ecological benefit in common bean and other species.

AbstractBackgroundRNAs to be used in transcriptome analysis must be of high quality and pure in order to ensure maximum representation of the expressed genes. RNA isolation is difficult in hazelnut tissues containing large amounts of secondary metabolite, phenolic compounds and the cell wall structure. Commonly used protocols for RNA isolation are those that require a lot of labor and time and also do not allow sufficient RNA isolation when applied to tissues rich in phenolic compounds. This study was aimed to develop an efficient method for isolation of total RNAs from bud of hazelnut to be used in RNA sequencing.Materials and methodsAn optimized new method was successfully applied on three different hazelnuts genotypes (Çakıldak, Palaz, Tombul) and about 25 times higher amount of total RNAs per mg fresh tissues were obtained compared to classical CTAB method. Different methods have been tried for the isolation of RNA from hazelnut tissues and the determination of the quality of the obtained RNAs.ResultsThe quality and quantity of isolalated total RNAs were determined by spectrophotometer, electrophoresis and PCR. This success has been caught without any compromise of purity since A260/A280 ratios ranged from 1.90 to 2.04 and A260/A230 ratios were >2.0 in all purified RNAs.ConclusionThe total RNAs isolated with new protocol was found to be suitable for RNA sequencing and other molecular applications.