Genome-wide identification, functional prediction, and evolutionary analysis of the R2R3-MYB superfamily in Brassica napus

Genome ◽  
2017 ◽  
Vol 60 (10) ◽  
pp. 797-814 ◽  
Author(s):  
Ali Hajiebrahimi ◽  
Hajar Owji ◽  
Shiva Hemmati

R2R3-MYB transcription factors (TFs) have been shown to play important roles in plants, including in development and in various stress conditions. Phylogenetic analysis showed the presence of 249 R2R3-MYB TFs in Brassica napus, called BnaR2R3-MYB TFs, clustered into 38 clades. BnaR2R3-MYB TFs were distributed on 19 chromosomes of B. napus. Sixteen gene clusters were identified. BnaR2R3-MYB TFs were characterized by motif prediction, gene structure analysis, and gene ontology. Evolutionary analysis revealed that BnaR2R3-MYB TFs are mainly formed as a result of whole-genome duplication. Orthologs and paralogs of BnaR2R3-MYB TFs were identified in B. napus, B. rapa, B. oleracea, and Arabidopsis thaliana using synteny-based methods. Purifying selection was pervasive within R2R3-MYB TFs. Kn/Ks values lower than 0.3 indicated that BnaR2R3-MYB TFs are being functionally converged. The role of gene conversion in the formation of BnaR2R3-MYB TFs was significant. Cis-regulatory elements in the upstream regions of BnaR2R3-MYB genes, miRNA targeting BnaR2R3MYB TFs, and post translational modifications were identified. Digital expression data revealed that BnaR2R3-MYB genes were highly expressed in the roots and under high salinity treatment after 24 h. BnaMYB21, BnaMYB141, and BnaMYB148 have been suggested for improving salt-tolerant B. napus. BnaR2R3-MYB genes were mostly up regulated on the 14th day post inoculation with Leptosphaeria biglobosa and L. maculan. BnaMYB150 is a candidate for increased tolerance to Leptospheria in B. napus.

2021 ◽  
Vol 12 ◽  
Author(s):  
Jian Li ◽  
Keyun Lin ◽  
Shuai Zhang ◽  
Jian Wu ◽  
Yujie Fang ◽  
...  

Myeloblastosis (MYB)-related transcription factors comprise a large subfamily of the MYB family. They play significant roles in plant development and in stress responses. However, MYB-related proteins have not been comprehensively investigated in rapeseed (Brassica napus L.). In the present study, a genome-wide analysis of MYB-related transcription factors was performed in rapeseed. We identified 251 Brassica napus MYB (BnMYB)-related members, which were divided phylogenetically into five clades. Evolutionary analysis suggested that whole genome duplication and segmental duplication events have played a significant role in the expansion of BnMYB-related gene family. Selective pressure of BnMYB-related genes was estimated using the Ka/Ks ratio, which indicated that BnMYB-related genes underwent strong purifying selection during evolution. In silico analysis showed that various development-associated, phytohormone-responsive, and stress-related cis-acting regulatory elements were enriched in the promoter regions of BnMYB-related genes. Furthermore, MYB-related genes with tissue or organ-specific, stress-responsive expression patterns were identified in B. napus based on temporospatial and abiotic stress expression profiles. Among the stress-responsive MYB-related genes, BnMRD107 was strongly induced by drought stress, and was therefore selected for functional study. Rapeseed seedlings overexpressing BnMRD107 showed improved resistance to osmotic stress. Our findings not only lay a foundation for further functional characterization of BnMYB-related genes, but also provide valuable clues to determine candidate genes for future genetic improvement of B. napus.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Wang ◽  
Ming-Hua Wu ◽  
Dong Xiao ◽  
Ruo-Lan Huang ◽  
Jie Zhan ◽  
...  

Abstract Background As an important cash crop, the yield of peanut is influenced by soil acidification and pathogen infection. Receptor-like protein kinases play important roles in plant growth, development and stress responses. However, little is known about the number, location, structure, molecular phylogeny, and expression of RLKs in peanut, and no comprehensive analysis of RLKs in the Al stress response in peanuts have been reported. Results A total of 1311 AhRLKs were identified from the peanut genome. The AhLRR-RLKs and AhLecRLKs were further divided into 24 and 35 subfamilies, respectively. The AhRLKs were randomly distributed across all 20 chromosomes in the peanut. Among these AhRLKs, 9.53% and 61.78% originated from tandem duplications and segmental duplications, respectively. The ka/ks ratios of 96.97% (96/99) of tandem duplication gene pairs and 98.78% (646/654) of segmental duplication gene pairs were less than 1. Among the tested tandem duplication clusters, there were 28 gene conversion events. Moreover, all total of 90 Al-responsive AhRLKs were identified by mining transcriptome data, and they were divided into 7 groups. Most of the Al-responsive AhRLKs that clustered together had similar motifs and evolutionarily conserved structures. The gene expression patterns of these genes in different tissues were further analysed, and tissue-specifically expressed genes, including 14 root-specific Al-responsive AhRLKs were found. In addition, all 90 Al-responsive AhRLKs which were distributed unevenly in the subfamilies of AhRLKs, showed different expression patterns between the two peanut varieties (Al-sensitive and Al-tolerant) under Al stress. Conclusions In this study, we analysed the RLK gene family in the peanut genome. Segmental duplication events were the main driving force for AhRLK evolution, and most AhRLKs subject to purifying selection. A total of 90 genes were identified as Al-responsive AhRLKs, and the classification, conserved motifs, structures, tissue expression patterns and predicted functions of Al-responsive AhRLKs were further analysed and discussed, revealing their putative roles. This study provides a better understanding of the structures and functions of AhRLKs and Al-responsive AhRLKs.


2019 ◽  
Vol 20 (22) ◽  
pp. 5796
Author(s):  
Qianqian Zhou ◽  
Qingchang Li ◽  
Peng Li ◽  
Songtao Zhang ◽  
Che Liu ◽  
...  

Carotenoid cleavage dioxygenases (CCDs) selectively catalyze carotenoids, forming smaller apocarotenoids that are essential for the synthesis of apocarotenoid flavor, aroma volatiles, and phytohormone ABA/SLs, as well as responses to abiotic stresses. Here, 19, 11, and 10 CCD genes were identified in Nicotiana tabacum, Nicotiana tomentosiformis, and Nicotiana sylvestris, respectively. For this family, we systematically analyzed phylogeny, gene structure, conserved motifs, gene duplications, cis-elements, subcellular and chromosomal localization, miRNA-target sites, expression patterns with different treatments, and molecular evolution. CCD genes were classified into two subfamilies and nine groups. Gene structures, motifs, and tertiary structures showed similarities within the same groups. Subcellular localization analysis predicted that CCD family genes are cytoplasmic and plastid-localized, which was confirmed experimentally. Evolutionary analysis showed that purifying selection dominated the evolution of these genes. Meanwhile, seven positive sites were identified on the ancestor branch of the tobacco CCD subfamily. Cis-regulatory elements of the CCD promoters were mainly involved in light-responsiveness, hormone treatment, and physiological stress. Different CCD family genes were predominantly expressed separately in roots, flowers, seeds, and leaves and exhibited divergent expression patterns with different hormones (ABA, MeJA, IAA, SA) and abiotic (drought, cold, heat) stresses. This study provides a comprehensive overview of the NtCCD gene family and a foundation for future functional characterization of individual genes.


2021 ◽  
Author(s):  
Weizheng Liang ◽  
Guipeng Li ◽  
Huanhuan Cui ◽  
Yukai Wang ◽  
Wencheng Wei ◽  
...  

AbstractDifferences in gene expression, which can arise from divergence in cis-regulatory elements or alterations in transcription factors binding specificity, are one of the most important causes of phenotypic diversity during evolution. By protein sequence analysis, we observed high sequence conservation in the DNA binding domain (DBD) of the transcription factor Cdx2 across many vertebrates, whereas three amino acid changes were exclusively found in mouse Cdx2 (mCdx2), suggesting potential positive selection in the mouse lineage. Multi-omics analyses were then carried out to investigate the effects of these changes. Surprisingly, there were no significant functional differences between mCdx2 and its rat homologue (rCdx2), and none of the three amino acid changes had any impact on its function. Finally, we used rat-mouse allodiploid embryonic stem cells (RMES) to study the cis effects of Cdx2-mediated gene regulation between the two rodents. Interestingly, whereas Cdx2 binding is largely divergent between mouse and rat, the transcriptional effect induced by Cdx2 is conserved to a much larger extent.Author summaryOur study 1) represented a first systematic analysis of species-specific adaptation in DNA binding pattern of transcription factor. Although the mouse-specific amino acid changes did not manifest functional impact in our system, several explanations may account for it (See Discussion part for the detail); 2) represented a first study of cis-regulation between two reproductively isolated species by using a novel allodiploid system; 3) demonstrated a higher conservation of transcriptional output than that of DNA binding, suggesting the evolvability/plasticity of the latter; 4) finally provided a rich data resource for Cdx2 mediated regulation, including gene expression, chromatin accessibility and DNA binding etc.


2022 ◽  
Vol 23 (2) ◽  
pp. 614
Author(s):  
Weiqi Sun ◽  
Mengdi Li ◽  
Jianbo Wang

Brassica napus and its diploid progenitors (B. rapa and B. oleracea) are suitable for studying the problems associated with polyploidization. As an important anti-stress protein, RCI2 proteins widely exist in various tissues of plants, and are crucial to plant growth, development, and stress response. In this study, the RCI2 gene family was comprehensively identified and analyzed, and 9, 9, and 24 RCI2 genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis showed that all of the identified RCI2 genes were divided into two groups, and further divided into three subgroups. Ka/Ks analysis showed that most of the identified RCI2 genes underwent a purifying selection after the duplication events. Moreover, gene structure analysis showed that the structure of RCI2 genes is largely conserved during polyploidization. The promoters of the RCI2 genes in B. napus contained more cis-acting elements, which were mainly involved in plant development and growth, plant hormone response, and stress responses. Thus, B. napus might have potential advantages in some biological aspects. In addition, the changes of RCI2 genes during polyploidization were also discussed from the aspects of gene number, gene structure, gene relative location, and gene expression, which can provide reference for future polyploidization analysis.


mSystems ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Soonkyu Hwang ◽  
Namil Lee ◽  
Donghui Choe ◽  
Yongjae Lee ◽  
Woori Kim ◽  
...  

ABSTRACT Identification of transcriptional regulatory elements in the GC-rich Streptomyces genome is essential for the production of novel biochemicals from secondary metabolite biosynthetic gene clusters (smBGCs). Despite many efforts to understand the regulation of transcription initiation in smBGCs, information on the regulation of transcription termination and posttranscriptional processing remains scarce. In this study, we identified the transcriptional regulatory elements in β-lactam antibiotic-producing Streptomyces clavuligerus ATCC 27064 by determining a total of 1,427 transcript 3′-end positions (TEPs) using the term-seq method. Termination of transcription was governed by three classes of TEPs, of which each displayed unique sequence features. The data integration with transcription start sites and transcriptome data generated 1,648 transcription units (TUs) and 610 transcription unit clusters (TUCs). TU architecture showed that the transcript abundance in TU isoforms of a TUC was potentially affected by the sequence context of their TEPs, suggesting that the regulatory elements of TEPs could control the transcription level in additional layers. We also identified TU features of a xenobiotic response element (XRE) family regulator and DUF397 domain-containing protein, particularly showing the abundance of bidirectional TEPs. Finally, we found that 189 noncoding TUs contained potential cis- and trans-regulatory elements that played a major role in regulating the 5′ and 3′ UTR. These findings highlight the role of transcriptional regulatory elements in transcription termination and posttranscriptional processing in Streptomyces sp. IMPORTANCE Streptomyces sp. is a great source of bioactive secondary metabolites, including antibiotics, antifungal agents, antiparasitic agents, immunosuppressant compounds, and other drugs. Secondary metabolites are synthesized via multistep conversions of the precursor molecules from primary metabolism, governed by multicomplex enzymes from secondary metabolite biosynthetic gene clusters. As their production is closely related with the growth phase and dynamic cellular status in response to various intra- and extracellular signals, complex regulatory systems tightly control the gene expressions related to secondary metabolism. In this study, we determined genome-wide transcript 3′-end positions and transcription units in the β-lactam antibiotic producer Streptomyces clavuligerus ATCC 27064 to elucidate the transcriptional regulatory elements in transcription termination and posttranscriptional processing by integration of multiomics data. These unique features, such as transcript 3′-end sequence, potential riboregulators, and potential 3′-untranslated region (UTR) cis-regulatory elements, can be potentially used to design engineering tools that can regulate the transcript abundance of genes for enhancing secondary metabolite production.


2021 ◽  
Author(s):  
Tahir Farooq ◽  
Muhammad Umar ◽  
Xiaoman She ◽  
Yafei Tang ◽  
Zifu He

Abstract Cotton leaf curl Multan virus (CLCuMuV) and its associated satellites are a major part of the cotton leaf curl disease (CLCuD) caused by the begomovirus species complex. Despite the implementation of potential disease management strategies, the incessant resurgence of resistance-breaking variants of CLCuMuV imposes a continuous threat to cotton production. Here, we present a focused effort to map the geographical prevalence, genomic diversity and molecular evolutionary endpoints that enhance disease complexity by facilitating the successful adaptation of CLCuMuV populations to the diversified ecosystems. Our results demonstrate that CLCuMuV populations are predominantly distributed in China while the majority of alphasatellites and betasatellites exist in Pakistan. We demonstrate that together with frequent recombination, an uneven genetic variation mainly drives CLCuMuV and its satellite’s virulence and evolvability. However, the pattern and distribution of recombination breakpoints greatly vary among viral and satellite sequences. The CLCuMuV, Cotton leaf curl Multan alphasatellite (CLCuMuA) and Cotton leaf curl Multan betasatellite (CLCuMuB) populations arising from distinct regions exhibit high mutation rates. Though evolutionary linked, these populations are independently evolving under strong purifying selection. These findings will facilitate to comprehensively understand the standing genetic variability and evolutionary patterns existing among CLCuMuV populations across major cotton-producing regions of the world.


Plant Disease ◽  
2021 ◽  
Author(s):  
Tao Luo ◽  
Guoqing Li ◽  
Long Yang

Oilseed rape (Brassica napus L.) is one of the most important oilseed crops in China. It is widely cultivated in China, with winter oilseed rape in Yangtze River basin and in southern China, and spring oilseed rape in northern China. In August 2017, a survey for Leptosphaeria spp. on spring oilseed rape was conducted in Minle county, Zhangye city, Gansu Province, China. The symptoms typical of blackleg on basal stems of oilseed rape were observed in the field. A large number of black fruiting bodies (pycnidia) were present on the lesions (Fig. 1A). The disease incidence of basal stem infection in the surveyed field was 19%. A total of 19 diseased stems were collected to isolate the pathogen. After surface sterilizing (75% ethanol for 30 s, 5% NaOCl for 60 s, followed by rinsing in sterilized water three times), diseased tissues were cultured on acidified potato dextrose agar (PDA) plates at 20°C for 7 days. Twelve fungal isolates were obtained. All fungal isolates produced typical tan pigment on PDA medium, and produced pycnidia after two weeks (Fig. 1B). Colony morphological characteristics indicated that these isolates might belong to Leptosphaeria biglobosa. To confirm identification, multiple PCR was conducted using the species-specific primers LmacF, LbigF, LmacR (Liu et al. 2006). Genomic DNA of each isolate was extracted using the cetyltrimethylammonium bromide (CTAB) method. DNA samples of L. maculans isolate UK-1 and L. biglobosa isolate W10 (Cai et al. 2015) were used as references. Only a 444-bp DNA band was detected in all 12 isolates and W10, whereas a 333-bp DNA band was detected only in the UK-1 isolate (Fig. 1C). PCR results suggested that these 12 isolates all belong to L. biglobosa. In addition, the internal transcribed spacer (ITS) region of these 12 isolates was analyzed for subspecies identification (Vincenot et al. 2008). Phylogenetic analysis based on ITS sequence showed that five isolates (Lb1134, Lb1136, Lb1138, Lb1139 and Lb1143) belonged to L. biglobosa ‘brassicae’ (Lbb) with 78% bootstrap support, and the other seven isolates (Lb1135, Lb1137, Lb1140, Lb1141, Lb1142, Lb1144 and Lb1145) belonged to L. biglobosa ‘canadensis’ (Lbc) with 95% bootstrap support (Fig. 1D). Two Lbb isolates (Lb1134 and Lb1136) and two Lbc isolates (Lb1142 and Lb1144) were randomly selected for pathogenicity testing on B. napus cultivar Zhongshuang No. 9 (Wang et al. 2002). Conidial suspensions (10 μL, 1 × 107 conidia mL-1) of these four isolates were inoculated on needle-wounded cotyledons (14-day-old seedling), with 10 cotyledons (20 wounded sites) per isolate. A further 10 wounded cotyledons were inoculated with water and served as controls. Seedlings were maintained in a growth chamber at 20°C with 100% relative humidity and a 12-h photoperiod. After 7 days, cotyledons inoculated with the four isolates showed necrotic lesions in the inoculated wounds. Control cotyledons had no symptoms (Fig. 2). Fungi re-isolated from the infected cotyledons showed similar colony morphology as the original isolates. Therefore, L. biglobosa ‘brassicae’ and L. biglobosa ‘canadensis’ appear to be the pathogens causing the observed blackleg symptoms on spring oilseed rape in Gansu, China. In previous studies, L. biglobosa ‘brassicae’ has been found in many crops in China, including oilseed rape (Liu et al. 2014; Cai et al. 2015), Chinese radish (Raphanus sativus) (Cai et al. 2014a), B. campestris ssp. chinensis var. purpurea (Cai et al. 2014b), broccoli (B. oleracea var. italica) (Luo et al. 2018), ornamental kale (B. oleracea var. acephala) (Zhou et al. 2019a), B. juncea var. multiceps (Zhou et al. 2019b), B. juncea var. tumida (Deng et al. 2020) and Chinese cabbage (B. rapa subsp. pekinensis) (Yu et al. 2021 accepted). To the best of our knowledge, this is the first report of L. biglobosa ‘canadensis’ causing blackleg on B. napus in China.


2021 ◽  
Author(s):  
Weizheng Liang ◽  
Guipeng Li ◽  
Huanhuan Cui ◽  
Yukai Wang ◽  
Wencheng Wei ◽  
...  

Abstract Background: Differences in gene expression, which arises from divergence in cis-regulatory elements or alterations in transcription factors (TFs) binding specificity, are one of the most important causes of phenotypic diversity during evolution. On one hand, changes in the cis-elements located in the vicinity of target genes affect TF binding and/or local chromatin environment, thereby modulating gene expression in one-to-one manner. On the other hand, alterations in trans-factors influence the expression of their target genes in a more pleiotropic fashion. Although evolution of amino acid sequences is much slower than that of non-coding regulatory elements, particularly for the TF DNA binding domains (DBD), it is still possible that changes in TF-DBD might have the potential to drive large phenotypic changes if the resulting effects have a net positive effect on the organism’s fitness. If so, species-specific changes in TF-DBD might be positively selected. So far, however, this possibility has been largely unexplored.Results: By protein sequence analysis, we observed high sequence conservation in the DNA binding domain (DBD) of the transcription factor Cdx2 across many vertebrates, whereas three amino acid changes were exclusively found in mouse Cdx2 (mCdx2), suggesting potential positive selection in the mouse lineage. Multi-omics analyses were then carried out to investigate the effects of these changes. Surprisingly, there were no significant functional differences between mCdx2 and its rat homologue (rCdx2), and none of the three amino acid changes had any impact on its function. Finally, we used rat-mouse allodiploid embryonic stem cells (RMES) to study the cis effects of Cdx2-mediated gene regulation between the two rodents. Interestingly, whereas Cdx2 binding is largely divergent between mouse and rat, the transcriptional effect induced by Cdx2 is conserved to a much larger extent.Conclusions: There were no significant functional differences between mCdx2 and its rat homologue (rCdx2), and none of the three amino acid changes had any impact on its function. Moreover, Cdx2 binding is largely divergent between mouse and rat, the transcriptional effect induced by Cdx2 is conserved to a much larger extent.


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