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The circadian clock refers to the formation of a certain rule in the long-term evolution of an organism, which is an invisible 'clock' in the body of an organism. As one of the largest TF families in higher plants, the MYB transcription factor is involved in plant growth and development. MYB is also inextricably correlated with the circadian rhythm. In this study, the transcriptome data of the tea plant 'Baiyeyihao' were measured at a photoperiod interval of 4 h (24 h). A total of 25,306 unigenes were obtained, including 14,615 unigenes that were annotated across 20 functional categories within the GO classification. Additionally, 10,443 single-gene clusters were annotated to 11 sublevels of metabolic pathways using KEGG. Based on the results of gene annotation and differential gene transcript analysis, 22 genes encoding MYB transcription factors were identified. The G10 group in the phylogenetic tree had 13 members, of which 5 were related to the circadian rhythm, accounting for 39%. The G1, G2, G8, G9, G15, G16, G18, G19, G20, G21 and G23 groups had no members associated with the circadian rhythm. Among the 22 differentially expressed MYB transcription factors, 3 members of LHY, RVE1 and RVE8 were core circadian rhythm genes belonging to the G10, G12 and G10 groups, respectively. Real-time fluorescence quantitative PCR was used to detect and validate the expression of the gene transcripts encoding MYB transcription factors associated with the circadian rhythm. [ABSTRACT FROM AUTHOR]

Nitrate nitrogen is an important nitrogen source for tea plants' growth and development. LBD transcription factors play important roles in response to the presence of nitrate in plants. The functional study of LBD transcription factors in tea plants remains limited. In this study, the LBD family gene CsLBD39 was isolated and characterized from tea plants. Sequence analysis indicated that CsLBD39 contained a highly conserved CX2CX6CX3CX domain. The phylogenetic tree assay showed that CsLBD39 belonged to class II subfamily of the LBD family. CsLBD39 was highly expressed in flowers and root; we determined that its expression could be induced by nitrate treatment. The CsLBD39 protein was located in the nucleus and has transcriptional activation activity in yeast. Compared with the wild type, overexpression of CsLBD39 gene in Arabidopsis resulted in smaller rosettes, shorter main roots, reduced lateral roots and lower plant weights. The nitrate content and the expression levels of genes related to nitrate transport and regulation were decreased in transgenic Arabidopsis hosting CsLBD39 gene. Compared with the wild type, CsLBD39 overexpression in transgenic Arabidopsis had smaller cell structure of leaves, shorter diameter of stem cross section, and slender and compact cell of stem longitudinal section. Under KNO3 treatment, the contents of nitrate, anthocyanins, and chlorophyll in leaves, and the content of nitrate in roots of Arabidopsis overexpressing CsLBD39 were reduced, the expression levels of nitrate transport and regulation related genes were decreased. The results revealed that CsLBD39 may be involved in nitrate signal transduction in tea plants as a negative regulator and laid the groundwork for future studies into the mechanism of nitrate response. [ABSTRACT FROM AUTHOR]

The plant-specific LBD (LATERAL ORGAN BOUNDARIES DOMAIN) genes belong to a major family of transcription factors that encode a zinc finger-like domain. This family plays crucial roles in plant development, including lateral organ development, pathogen response, pollen development, plant regeneration and hormone response. However, there is no detailed information of LBD genes in the tea plant. Tea plant [Camellia sinensis (L.) O. Kuntze] is a perennial evergreen woody crop that is cultivated worldwide. Tea leaves are used as a non-alcoholic beverage, which is known for its beneficial ingredients and multiple flavours. In this study, a total of 31 CsLBD genes were identified and characterized based on the genome of C. sinensis. CsLBD factors and Arabidopsis counterparts were clustered into 10 subgroups after phylogenetic analysis. Conserved motif analysis revealed that CsLBD proteins with a close evolutionary relationship possessed uniform or similar motif compositions. The interaction networks of LBD proteins in C. sinensis were established according to the data in Arabidopsis. Seven CsLBD genes were examined through qRT-PCR (quantitative real time polymerase chain reaction) in tea plant cultivar, 'Longjing43'. The expression profiles of these CsLBD genes were investigated in different tissues (i.e. root, stem, leaf and flower) and subjected to five hormonal stimuli (i.e. abscisic acid, gibberellin acid, ethephon, methyl jasmonate and salicylic acid). This study provides an extensive overview of the CsLBD family genes and a valuable foundation for future functional studies of CsLBD factors. [ABSTRACT FROM AUTHOR]

Dehydration-responsive element-binding protein (DREB) transcription factors play key roles in plant stress signal transduction pathways. We herein describe the functions of a Camellia sinensis DREB transcription factor (CsDREB) in response to abiotic stress. Subcellular localization analyses indicated that the CsDREB localizes to the nucleus. CsDREB expression in C. sinensis leaves was induced by heat, cold, drought, high salinity, HO, and exogenous abscisic acid (ABA). Additionally, CsDREB showed no transcriptional activation in Saccharomyces cerevisiae. Transgenic Arabidopsis thaliana plants overexpressing CsDREB exhibited enhanced tolerance to salt and drought stresses. The overexpression of CsDREB in A. thaliana plants resulted in the up-regulated expression of ABA-dependent stress-induced genes (i.e., AtRD29B, AtRAB18, AtABI1, and AtABI2) and ABAindependent stress-induced genes (i.e., AtCOR15a and AtRD29A). Furthermore, an analysis of the CsDREB promoter sequence revealed the presence of several abiotic and biotic stress-related motifs, along with the developmental stageand tissue-specific elements. An examination of the transient expression of the CsDREB promoter in Nicotiana benthamiana leaves revealed that the promoter is highly responsive to ABA and methyl jasmonate. Collectively, these results suggest that CsDREB may increase plant tolerance to salt and drought stresses via both ABA-dependent and ABAindependent pathways. [ABSTRACT FROM AUTHOR]

In higher plant, ERF subfamily transcription factor involved in growth and development, signal transduction,and regulated the expression of related genes in order to improve the resistance to the abiotic stresses, such as high temperature, low temperature, drought and salt damage. Here, the molecular characterization, tissue expression and abiotic stresses response of the AP2/ ERF-B3 group transcription factor in different tea varieties were investigated. The results will contribute to understanding the roles of AP2/ ERF-B3 transcription factor in tea plant(Camellia sinensis). The CsERF-B3 genes,which encode to the AP2/ ERF-B3 transcription factor,were cloned by RT-PCR method using cDNA as template, from two tea plant cultivars' Anjibaicha' and 'Yingshuang', respectively. Then, cDNA and deduced amino acid sequence, phylogenetic tree, physical and chemical characterization, hydrophilicity/ hydrophobicity, molecular modeling and disordered residues were analyzed by related software. The expression profiles of the CsERF-B3 gene in the tissues of tea plants(roots, stems, leaves and flowers)were detected. The leaves, which were respectively treated with 2 h under 4 kinds of abiotic stresses(4 °C low temperature, 38 °C high temperature,200 g·L-1 PEG and 200 mmol·L-1 NaCl), were also detected by the quantitative real-time PCR analysis. Then,the multiple comparisons and plotting were finished by using Excel program. The results of sequence alignments and phylogenetic analysis showed that lengths of CsERF-B3 genes from the two tea plant cultivars were 639 bp, encoding 212 amino acids, respectively. The transcription factor of CsERF-B3 between 110-145 amino acid sites contained the AP2 DNA binding domain where both contained a conservative WLG and YRG element. The CsERF-B3 of tea plants was a typical AP2/ ERF family transcription factors in plants. Homologous phylogenetic tree showed that this ERF transcription factor was the closest relatives to AtERF1(AT4G17500.1)and AtERF2(AT5G47220.1)in Arabidopsis, they all belong to group B3,one group of the ERF subfamily transcription factors. The CsERF-B3 was hydrophilic protein and chemical properties were similar among related species. The CsERF-B3 and AtERF1 had similar three-dimension structure and disordered residues feature. The homologies of ABERF and YSERF were 92.1% and 93.7% compared with the DNA binding domain of crystal structure PDB ID:1gcc,respectively. The highest expression levels of the CsERF-B3 genes were found in the root of tea plant. The CsERF-B3 gene could respond quickly to high temperature(38 °C), low temperature (4 °C) and high-salinity(200 mmol·L-1 NaCl) treatments, respectively. The expression of CsERF-B3 gene was induced by abiotic stresses in tea plant, indicating that the transcription factor of AP2/ ERF-B3 plays an important role in the regulation of abiotic stress in tea plant. [ABSTRACT FROM AUTHOR]

Abstract: The nucleotide sequence of the entire grapevine genome has been obtained and its draft sequence has served as the model for fruit crops. Many transcription factors involved in stress-resistance pathways have been identified, among which the AP2/ERF is a large, and one of the most important families of transcription factors in plants. In this study, 132 putative transcription factor genes in the AP2/ERF family were identified from the database of the Vitis vinifera (grapevine) genome, and were compared with those from three other completely sequenced genomes, Arabidopsis thaliana, Populus trichocarpa (poplar), and Oryza sativa (rice). The grapevine AP2/ERF genes were classified into four subfamilies, AP2, DREB, ERF, RAV, and a soloist, and there were considerable variations among the subfamily members comparing with those in other species. The amino acid sequence, composition, physical and chemical characterization, phylogenetic tree, conserved domain sequences, function domain, and locations on chromosomes were predicted and analyzed. In silico mapping of the gene loci showed that AP2/ERF family genes of grapevine were localized on 19 linkage groups. The extant AP2/ERF gene family in grapevine apparently resulted from whole genome, segmental and tandem duplications. Several grapevine AP2/ERF genes have been identified which are orthologous to those characterized in Arabidopsis with known functions. [Copyright &y& Elsevier]

Tea plant (Camellia sinensis (L.) O. Kuntze) is a perennial evergreen woody plant, and its leaves contain various beneficial ingredients and have healthy efficacy. HD-Zip (homeodomain-leucine zipper) transcription factors (TFs) are widely distributed in plants and play an important role in plant growth and environmental response. To date, knowledge on HD-Zip gene family in tea plant is still limited. In this study, 33 HD-Zip TFs were selected based on the genomic and transcriptomic databases of tea plant. The conserved domains and common motifs of these TFs were predicted and analyzed. These 33 Cshdz TFs were divided into four groups (HD-Zip I, HD-Zip II, HD-Zip III, and HD-Zip IV). The interaction network of the HD-Zip proteins of tea plant was established based on the data of Arabidopsis. In addition, the expression levels of these Cshdz genes in tea plant cv. 'Longjing43' were detected and analyzed under five abiotic stress treatments. Results showed that the different expression profiles of Cshdz genes were associated with different abiotic stress treatments. Our findings suggested a potential relationship between the resistance of tea plant and its Cshdz genes. • A total of 33 HD-Zip transcription factors were isolated from tea plant. • The phylogenetic tree, conserved motifs, and characteristics were performed. • The expression profiles of Cshdz genes response to abiotic stress treatments in tea plant. [ABSTRACT FROM AUTHOR]

• CsLBD37 , a LBD/ASL transcription factor, was cloned and functionally characterized. • CsLBD37 alters nitrate content by decreasing the expression levels of nitrogen-responsive genes. • CsLBD37 alters the morphology of main roots and lateral roots in transgenic Arabidopsis. The tea plant is widely cultivated as an economic crop throughout the world. Nitrate is an essential nutrient, as well as a key signaling molecule that controls plant growth and development. LBD transcription factors play important roles in plant nitrate response. The study of the functions of LBD transcription factors in tea plant, on the other hand, is still limited. In this work, CsLBD37 , a nitrate-induced LBD family gene from tea plant was isolated and characterized. The CsLBD37 protein was located in the nucleus and showed transcriptional activity in yeast. Under 5 mM nitrate treatment, CsLBD37 overexpression in transgenic Arabidopsis resulted in shorter main roots (0.16-, 0.45-, and 0.65-fold of wild type plants), fewer lateral roots (0.1-, 0.18-, and 0.27-fold of wild type plants), and reduced plant weight (0.36-, 0.31-, and 0.34-fold of wild type plants). In addition, the transgenic Arabidopsis contained a reduced nitrate concentration (the nitrate content of OE-1 and OE-2 in leaves was 0.45 and 0.44 times of that in non-transgenic plants, respectively) and lower expression levels of nitrate-responsive genes. In transgenic Arabidopsis, CsLBD37 overexpression results in shorter plants, earlier blooming and fewer seeds. The results proved that CsLBD37 regulates nitrate signaling in tea plants, which lays the groundwork for future studies on the nitrate response mechanism. [ABSTRACT FROM AUTHOR]

Polyphenol compounds are natural antioxidants, which are rich in anti-inflammatory and antioxidant components. They have a wide range of medicinal benefits that are believed to improve human health across various aspects; especially its anticancer effect has been gradually confirmed. The anticancer effect of polyphenols is mainly based on their strong antioxidant and immunomodulatory effects. The innate and adaptive immune responses as well as the development and maintenance of cells and tissues of the immune system are regulated by the NF-κB family of transcription factors. Dysregulation of NF-κB can lead to autoimmune diseases, chronic inflammation, and even cancer. Polyphenol compounds can exert antioxidant and immunomodulatory effects by targeting NF-κB, thus hindering the occurrence and development of tumors.Polyphenol compounds have unique advantages over conventional anticancer therapies such as chemotherapy because they have few side effects and do not cause toxicity to healthy cells. Additionally, they can attenuate the toxic effects of current anticancer therapies. Based on these characteristics, polyphenols have great potential in the prevention and treatment of cancer. This article systematically summarizes the mechanism of NF-κB in tumor genesis, progression, metastasis, angiogenesis, and drug resistance. In addition, we present the anticancer effect of polyphenol compounds by targeting NF-κB during the different stages of tumorigenesis. [Display omitted] • Polyphenol compounds have potent anti-inflammatory and antioxidant effects. • Polyphenol compounds are potential tumor immunotherapy modulators. • NF-κB is an important molecular target of cancer. • Polyphenol compounds have the advantages of low side effects and so on. • An important anti-tumor target of Polyphenol compounds is NF-κB. [ABSTRACT FROM AUTHOR]