Presence Of Cis-acting Regulatory Elements Research Articles

Genome-Wide Analyses of CCHC Family Genes and Their Expression Profiles under Drought Stress in Rose (Rosa chinensis).

CCHC-type zinc finger proteins (CCHC-ZFPs), ubiquitous across plant species, are integral to their growth, development, hormonal regulation, and stress adaptation. Roses (Rosa sp.), as one of the most significant and extensively cultivated ornamentals, account for more than 30% of the global cut-flower market. Despite its significance, the CCHC gene family in roses (Rosa sp.) remains unexplored. This investigation identified and categorized 41 CCHC gene members located on seven chromosomes of rose into 14 subfamilies through motif distribution and phylogenetic analyses involving ten additional plant species, including Ginkgo biloba, Ostreococcus lucimarinus, Arabidopsis thaliana, and others. This study revealed that dispersed duplication likely plays a crucial role in the diversification of the CCHC genes, with the Ka/Ks ratio suggesting a history of strong purifying selection. Promoter analysis highlighted a rich presence of cis-acting regulatory elements linked to both abiotic and biotic stress responses. Differential expression analysis under drought conditions grouped the 41 CCHC gene members into five distinct clusters, with those in group 4 exhibiting pronounced regulation in roots and leaves under severe drought. Furthermore, virus-induced gene silencing (VIGS) of the RcCCHC25 member from group 4 compromised drought resilience in rose foliage. This comprehensive analysis lays the groundwork for further investigations into the functional dynamics of the CCHC gene family in rose physiology and stress responses.

In Silico Characterization of Lycopene Beta Cyclase (LCYB) and Lycopene Epsilon Cyclase (LCYE) Genes from DH-Pahang (Musa acuminata, A Genome) and DH-PKW (Musa balbisiana, B Genome)

Alpha (α) and beta (β)-carotene are among the nutritious contents of bananas, with the unique feature of a high ratio of α-/β-carotene. Research on the gene and protein of the key enzymes determining the ratio of α-/β-carotene in bananas, namely lycopene beta cyclase (LCYB) and lycopene epsilon cyclase (LCYE), is currently not well defined. Hence, this study aimed to compare the characters of the LCYB and LCYE genes and their putative proteins from Musa acuminata 'DH-Pahang' and Musa balbisiana 'DH-PKW'. The corresponding nucleotide sequences from both species were aligned to detect similarities in the gene structure. Their protein products were characterized at the primary and tertiary levels. The phylogenetic tree was constructed based on nucleotide and protein sequences. The result showed that the gene structure between these two species is similar in LCYB in chromosome 9 but different in LCYB in chromosome 7 and LCYE. The presence of cis-acting regulatory elements in response to light dominated the 2000 nucleotide region of the 5'UTR of LCYB and LCYE genes in both species. Based on protein alignment and domain analysis, the NADB_Rossmann superfamily domain was detected in both LCYB and LCYE. Alignment of the three-dimensional protein structure showed a significant difference between MaLCYB.c07 and MbLCYB.c07 only. The phylogenetic tree based on protein sequences indicated the distant relationship of MaLCYB.c07 and MbLCYB.c07 with other LCYB ingroup OTUs. The results of this study could provide a molecular basis related to the exploration of bananas as a promising functional food to meet the needs of provitamin A.

Weighted Gene Correlation Network Analysis (WGCNA) of Arabidopsis Somatic Embryogenesis (SE) and Identification of Key Gene Modules to Uncover SE-Associated Hub Genes.

Somatic embryogenesis (SE), which occurs naturally in many plant species, serves as a model to elucidate cellular and molecular mechanisms of embryo patterning in plants. Decoding the regulatory landscape of SE is essential for its further application. Hence, the present study was aimed at employing Weighted Gene Correlation Network Analysis (WGCNA) to construct a gene coexpression network (GCN) for Arabidopsis SE and then identifying highly correlated gene modules to uncover the hub genes associated with SE that may serve as potential molecular targets. A total of 17,059 genes were filtered from a microarray dataset comprising four stages of SE, i.e., stage I (zygotic embryos), stage II (proliferating tissues at 7 days of induction), stage III (proliferating tissues at 14 days of induction), and stage IV (mature somatic embryos). This included 1,711 transcription factors and 445 EMBRYO DEFECTIVE genes. GCN analysis identified a total of 26 gene modules with the module size ranging from 35 to 3,418 genes using a dynamic cut tree algorithm. The module-trait analysis revealed that four, four, seven, and four modules were associated with stages I, II, III, and IV, respectively. Further, we identified a total of 260 hub genes based on the degree of intramodular connectivity. Validation of the hub genes using publicly available expression datasets demonstrated that at least 78 hub genes are potentially associated with embryogenesis; of these, many genes remain functionally uncharacterized thus far. In silico promoter analysis of these genes revealed the presence of cis-acting regulatory elements, “soybean embryo factor 4 (SEF4) binding site,” and “E-box” of the napA storage-protein gene of Brassica napus; this suggests that these genes may play important roles in plant embryo development. The present study successfully applied WGCNA to construct a GCN for SE in Arabidopsis and identified hub genes involved in the development of somatic embryos. These hub genes could be used as molecular targets to further elucidate the molecular mechanisms underlying SE in plants.

Genome-Wide Analyses of Aspartic Proteases on Potato Genome (Solanum tuberosum): Generating New Tools to Improve the Resistance of Plants to Abiotic Stress.

Aspartic proteases are proteolytic enzymes widely distributed in living organisms and viruses. Although they have been extensively studied in many plant species, they are poorly described in potatoes. The present study aimed to identify and characterize S. tuberosum aspartic proteases. Gene structure, chromosome and protein domain organization, phylogeny, and subcellular predicted localization were analyzed and integrated with RNAseq data from different tissues, organs, and conditions focused on abiotic stress. Sixty-two aspartic protease genes were retrieved from the potato genome, distributed in 12 chromosomes. A high number of intronless genes and segmental and tandem duplications were detected. Phylogenetic analysis revealed eight StAP groups, named from StAPI to StAPVIII, that were differentiated into typical (StAPI), nucellin-like (StAPIIIa), and atypical aspartic proteases (StAPII, StAPIIIb to StAPVIII). RNAseq data analyses showed that gene expression was consistent with the presence of cis-acting regulatory elements on StAP promoter regions related to water deficit. The study presents the first identification and characterization of 62 aspartic protease genes and proteins on the potato genome and provides the baseline material for functional gene determinations and potato breeding programs, including gene editing mediated by CRISPR.

Common and distinct organ and stress responsive transcriptomic patterns in Oryza sativa and Arabidopsis thaliana

BackgroundArabidopsis thaliana is clearly established as the model plant species. Given the ever-growing demand for food, there is a need to translate the knowledge learned in Arabidopsis to agronomically important species, such as rice (Oryza sativa). To gain a comparative insight into the similarities and differences into how organs are built and how plants respond to stress, the transcriptomes of Arabidopsis and rice were compared at the level of gene orthology and functional categorisation.ResultsOrgan specific transcripts in rice and Arabidopsis display less overlap in terms of gene orthology compared to the orthology observed between both genomes. Although greater overlap in terms of functional classification was observed between root specific transcripts in rice and Arabidopsis, this did not extend to flower, leaf or seed specific transcripts. In contrast, the overall abiotic stress response transcriptome displayed a significantly greater overlap in terms of gene orthology compared to the orthology observed between both genomes. However, ~50% or less of these orthologues responded in a similar manner in both species. In fact, under cold and heat treatments as many or more orthologous genes responded in an opposite manner or were unchanged in one species compared to the other. Examples of transcripts that responded oppositely include several genes encoding proteins involved in stress and redox responses and non-symbiotic hemoglobins that play central roles in stress signalling pathways. The differences observed in the abiotic transcriptomes were mirrored in the presence of cis-acting regulatory elements in the promoter regions of stress responsive genes and the transcription factors that potentially bind these regulatory elements. Thus, both the abiotic transcriptome and its regulation differ between rice and Arabidopsis.ConclusionsThese results reveal significant divergence between Arabidopsis and rice, in terms of the abiotic stress response and its regulation. Both plants are shown to employ unique combinations of genes to achieve growth and stress responses. Comparison of these networks provides a more rational approach to translational studies that is based on the response observed in these two diverse plant models.

Analysis of LacZ reporter genes in transgenic embryos suggests the presence of several cis‐acting regulatory elements in the murine Hoxb‐6 gene

Homeobox genes are expressed in stage-, region-, and tissue-specific patterns during embryonic development of the mouse. In order to understand the underlying regulatory mechanisms the murine homeobox gene Hoxb-6 was analyzed for the presence of cis-acting regulatory elements. Transgenic mouse embryos and lines were generated which contained the LacZ reporter gene under the control of different fragments from the Hoxb-6 gene. In total, 13.2 kb of genomic DNA covering the entire Hoxb-6 region were analyzed. Our results suggested the presence of three regulatory regions in the Hoxb-6 gene: a limb/LPM element which directed gene expression into restricted regions of the developing limb buds and the ventro-lateral and visceral mesenchyme, a regulatory element required for gene expression into ventral regions of the developing spinal cord, and a third element necessary for directing gene expression into developing mesonephric tubules and mesonephric ducts. We demonstrated that the limb/LPM element functions as an enhancer in a promoter- and orientation-independent manner. The comparison of the expression patterns of the reporter gene constructs and the endogenous Hoxb-6 gene revealed that the regulatory regions were able to reproduce part of the Hoxb-6 pattern. However, not all control elements necessary to completely mimic the endogenous Hoxb-6 expression pattern could be detected, although the entire Hoxb-6 genomic region has been analyzed. These observations suggest that for some aspects of Hoxb-6 gene regulation the integrity of large genomic regions of the Hoxb cluster is required.