scholarly journals Comparative analysis of basic helix–loop–helix gene family among Brassica oleracea, Brassica rapa, and Brassica napus

2019 ◽  
Author(s):  
Liming Miao ◽  
Yingying Gao ◽  
Kun Zhao ◽  
Lijun Kong ◽  
Shubo Yu ◽  
...  

Abstract Background: The basic helix–loop–helix (bHLH) transcription factors exist widely in eukaryotes and play important roles in development and stress response regulation in plants. The bHLH gene family has been identified in many species, except for Brassica oleracea and Brassica napus thus far. This study aims to identify the bHLH family members in B. oleracea, Brassica rapa, and B. napus and elucidate the expression, duplication, phylogeny and evolution characters of these genes. Result: A total of 268 bHLH genes in B. oleracea, 440 genes in B. napus, and 251 genes in B. rapa, including 21 new bHLH members, have been identified. Subsequently, the analysis of the phylogenetic tree, conserved motifs and gene structures showed that the members in the same subfamily were highly conserved. Most Ka/Ks values of the homologous gene were <1, which indicated that the homologous genes suffered from strong purifying selection for retention. The Ks values of the three Brassica crops were concentrated in the range of 0.3–0.5. Hence, the divergence time of the bHLH gene family between Brassica crops and Arabidopsis thaliana is approximately 10–18 MYA. The retention rates of BrabHLH and BolbHLH genes were 51.6% and 55.1%, respectively. A total of 182 genes were lost in B. napus after tetraploid. GO annotations of BolbHLH genes showed that most genes focused on DNA-binding transcription factor, DNA-binding, and protein dimerization activities. The temporal and spatial expression patterns of 50 BolbHLH genes were diverse, some of which showing high expression in the reproduction tissue, while some had high expression in the root. The comparison of expression patterns between B. rapa and B. napus showed that they had similar expression patterns in the root and contrasting patterns in the stems, leaves, and reproduction tissues. However, the expression patterns of B. oleracea and B. napus were different. Conclusion: This study is the first to report about the gene family analysis of the bHLH gene in B. oleracea and B. napus. Our results not only offer useful information on the functional analysis of the bHLH gene but also provide new insights into the evolution of Brassica spp.

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 914
Author(s):  
Shan ◽  
Zhang ◽  
Yu ◽  
Wang ◽  
Li ◽  
...  

Basic helix–loop–helix (bHLH) transcription factor (TF) family is commonly found in eukaryotes, which is one of the largest families of regulator proteins. It plays an important role in plant growth and development, as well as various biotic and abiotic stresses. However, a comprehensive analysis of the bHLH family has not been reported in Brassica oleracea. In this study, we systematically describe the BobHLHs in the phylogenetic relationships, expression patterns in different organs/tissues, and in response to chilling stress, and gene and protein characteristics. A total of 234 BobHLH genes were identified in the B. oleracea genome and were further clustered into twenty-three subfamilies based on the phylogenetic analyses. A large number of BobHLH genes were unevenly located on nine chromosomes of B. oleracea. Analysis of RNA-Seq expression profiles revealed that 21 BobHLH genes exhibited organ/tissue-specific expression. Additionally, the expression of six BobHLHs (BobHLH003, -048, -059, -093, -109, and -148) were significantly down-regulated in chilling-sensitive cabbage (CS-D9) and chilling-tolerant cabbage (CT-923). At 24h chilling stress, BobHLH054 was significantly down-regulated and up-regulated in chilling-treated CS-D9 and CT-923. Conserved motif characterization and exon/intron structural patterns showed that BobHLH genes had similar structures in the same subfamily. This study provides a comprehensive analysis of BobHLH genes and reveals several candidate genes involved in chilling tolerance of B. oleracea, which may be helpful to clarify the roles of bHLH family members and understand the regulatory mechanisms of BobHLH genes in response to the chilling stress of cabbage.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1439
Author(s):  
Yang Ye ◽  
Haodong Xin ◽  
Xiting Gu ◽  
Jianwen Ma ◽  
Lingli Li

As one of the largest TF families+ in plants, the basic helix-loop-helix (bHLH) family plays an important part in the growth and development of many plants. FLOWERING BHLH (FBH) encodes a bHLH-type transcriptional factor related to the flowering process. Poplar is a model woody plant as well as an important economic tree species with a small genome. However, the characteristics of the bHLHs and FBHs gene family in the newest version of Populustrichocarpa genome have not been analyzed yet. We identified 233 PtbHLHs and 10 PtFBHs in the newest version genome, and PtbHLHs were classified into 21 groups with FBH subfamily occupying one, supported by phylogenetic analysis, exon–intron patterns, and conserved protein motifs. These PtHLHs were distributed on 19 chromosomes unevenly and expressed in nucleus mainly. Gene duplication and synteny analysis have indicated that the PtbHLHs gene family has undergone strong purification selection during the evolution process. The cis-elements analysis has suggested that PtbHLHs may be related to the growth and development. Conserved residues of FBHs among Arabidopsis and poplar were also identified. Expression of 227 PtHLH genes (6 unmatched, 13 no expressed) showed diverse patterns in different tissues, implying their multiple functions. Protein–protein interaction network prediction and expression patterns in three states of the flowering process (Flowers-Dormant, Flowers-Expanding and Flowers-Expanded) suggested that some members of PtbHLH and PtFBH family may be involved in the flowering process. Our comprehensive and systematic analysis can provide some valuable clues and basic reference toward further investigations on physiological and molecular functions of PtbHLHs.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Di Wu ◽  
Anqi Liu ◽  
Xiaoyu Qu ◽  
Jiayi Liang ◽  
Min Song

Abstract Background Xyloglucan endotransglucosylase/hydrolase genes (XTHs) are a multigene family and play key roles in regulating cell wall extensibility in plant growth and development. Brassica rapa and Brassica oleracea contain XTHs, but detailed identification and characterization of the XTH family in these species, and analysis of their tissue expression profiles, have not previously been carried out. Results In this study, 53 and 38 XTH genes were identified in B. rapa and B. oleracea respectively, which contained some novel members not observed in previous studies. All XTHs of B. rapa, B. oleracea and Arabidopsis thaliana could be classified into three groups, Group I/II, III and the Early diverging group, based on phylogenetic relationships. Gene structures and motif patterns were similar within each group. All XTHs in this study contained two characteristic conserved domains (Glyco_hydro and XET_C). XTHs are located mainly in the cell wall but some are also located in the cytoplasm. Analyses of the mechanisms of gene family expansion revealed that whole-genome triplication (WGT) events and tandem duplication (TD) may have been the major mechanisms accounting for the expansion of the XTH gene family. Interestingly, TD genes all belonged to Group I/II, suggesting that TD was the main reason for the largest number of genes being in these groups. B. oleracea had lost more of the XTH genes, the conserved domain XET_C and the conserved active-site motif EXDXE compared with B. rapa, consistent with asymmetrical evolution between the two Brassica genomes. A majority of XTH genes exhibited different tissue-specific expression patterns based on RNA-seq data analyses. Moreover, there was differential expression of duplicated XTH genes in the two species, indicating that their functional differentiation occurred after B. rapa and B. oleracea diverged from a common ancestor. Conclusions We carried out the first systematic analysis of XTH gene families in B. rapa and B. oleracea. The results of this investigation can be used for reference in further studies on the functions of XTH genes and the evolution of this multigene family.


2020 ◽  
Author(s):  
Di Wu ◽  
Anqi Liu ◽  
Xiaoyu Qu ◽  
Jiayi Liang ◽  
Min Song

Abstract Background: Xyloglucan endotransglucosylase/hydrolase genes ( XTHs ) are a multigene family and play key roles in regulating cell wall extensibility in plant growth and development. Brassica rapa and Brassica oleracea contain XTHs, but detailed identification and characterization of the XTH family in these species, and analysis of their tissue expression profiles, have not previously been carried out. Results: In this study, 53 and 38 XTH genes were identified in B. rapa and B. oleracea respectively, which contained some novel members not observed in previous studies. All XTHs of B. rapa , B. oleracea and Arabidopsis thaliana could be classified into three groups, Group I/II, III and the Early diverging group, based on phylogenetic relationships. Gene structures and motif patterns were similar within each group. All XTHs in this study contained two characteristic conserved domains (Glyco_hydro and XET_C). XTHs are located mainly in the cell wall but some are also located in the cytoplasm. Analyses of the mechanisms of gene family expansion revealed that whole-genome triplication (WGT) events and tandem duplication (TD) may have been the major mechanisms accounting for the expansion of the XTH gene family. Interestingly, TD genes all belonged to Group I/II, suggesting that TD was the main reason for the largest number of genes being in these groups. B. oleracea had lost more of the XTH genes, the conserved domain XET_C and the conserved active-site motif EXDXE compared with B. rapa , consistent with asymmetrical evolution between the two Brassica genomes. A majority of XTH genes exhibited different tissue-specific expression patterns based on RNA-seq data analyses. Moreover, there was differential expression of duplicated XTH genes in the two species, indicating that their functional differentiation occurred after B. rapa and B. oleracea diverged from a common ancestor. Conclusions: We carried out the first systematic analysis of XTH gene families in B. rapa and B. oleracea . The results of this investigation can be used for reference in further studies on the functions of XTH genes and the evolution of this multigene family.


2020 ◽  
Author(s):  
Yan Lv ◽  
Dan Luo ◽  
Ziqi Jia ◽  
Yong Cheng ◽  
Xiling Zou

Abstract Background: The β amylase (BAM) gene family, known for their property of catalytic ability to hydrolyze starch to maltose units, has been recognized to play critical roles in metabolism and gene regulation. To date, BAM genes have not been characterized in oil crops.Results: In this study, the genome wide survey revealed the identification of 30 BnaBAM genes in Brassica napus (B. napus), 11 BraBAM genes in Brassica rapa (B. rapa), 20 BoBAM genes in Brassica oleracea (B. oleracea), which were divided into 4 subfamilies according to the sequence similarity and phylogenetic relationships. All the BAM genes identified in the allotetraploid genome of B. napus, as well as two parental related species (B. rapa and B. oleracea), were analyzed for the gene structures, chromosomal distribution and collinearity, the sequence alignment of the core glucosyl hydrolase domains was further applied. 30 BnaBAMs, 11 BraBAMs and 17 BoBAMs exhibited uneven distribution on chromosomes of Brassica crops. The similar structural compositions of BAM genes in the same subfamily suggested that they were relatively conserved. Abiotic stresses pose one of the major constraints to plant growth and productivity worldwide. Thus, the responsiveness of BnaBAM genes under abiotic stresses were analyzed in B. napus. The expression patterns revealed a stress responsive behavior of all members, of which BnaBAM3s were more prominent. These differential expression patterns suggested an intricate regulation of BnaBAMs elicited by environmental stimuli. Conclusion: Altogether, the present study provides first insights into the BAM gene family of Brassica crops, which lays the foundation for investigating the roles of stress--responsive BnaBAM candidates in B. napus.


2010 ◽  
Vol 36 (8) ◽  
pp. 1280-1285 ◽  
Author(s):  
Jun LI ◽  
Li-Xia LUO ◽  
Zhuan WANG ◽  
Jun LI ◽  
Kun-Rong CHEN ◽  
...  

Development ◽  
1997 ◽  
Vol 124 (6) ◽  
pp. 1169-1178 ◽  
Author(s):  
W.C. Jen ◽  
D. Wettstein ◽  
D. Turner ◽  
A. Chitnis ◽  
C. Kintner

Segmentation of the vertebrate embryo begins when the paraxial mesoderm is subdivided into somites, through a process that remains poorly understood. To study this process, we have characterized X-Delta-2, which encodes the second Xenopus homolog of Drosophila Delta. Strikingly, X-Delta-2 is expressed within the presomitic mesoderm in a set of stripes that corresponds to prospective somitic boundaries, suggesting that Notch signaling within this region establishes a segmental prepattern prior to somitogenesis. To test this idea, we introduced antimorphic forms of X-Delta-2 and Xenopus Suppressor of Hairless (X-Su(H)) into embryos, and assayed the effects of these antimorphs on somite formation. In embryos expressing these antimorphs, the paraxial mesoderm differentiated normally into somitic tissue, but failed to segment properly. Both antimorphs also disrupted the segmental expression of X-Delta-2 and Hairy2A, a basic helix-loop-helix (bHLH) gene, within the presomitic mesoderm. These observations suggest that X-Delta-2, via X-Notch-1, plays a role in segmentation, by mediating cell-cell interactions that underlie the formation of a segmental prepattern prior to somitogenesis.


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