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Lignin is an important component of plant cell walls and plays crucial roles in the essential agronomic traits of tea quality and tenderness. However, the molecular mechanisms underlying the regulation of lignin biosynthesis in tea plants remain unclear. CsWRKY13 acts as a negative regulator of lignin biosynthesis in tea plants. In this study, we identified a GRAS transcription factor, phytochrome A signal transduction 1 (CsPAT1), that interacts with CsWRKY13. Silencing CsPAT1 expression in tea plants and heterologous overexpression in Arabidopsis demonstrated that CsPAT1 positively regulates lignin accumulation. Further investigation revealed that CsWRKY13 directly binds to the promoters of CsPAL and CsC4H and suppresses transcription of CsPAL and CsC4H. CsPAT1 indirectly affects the promoter activities of CsPAL and CsC4H by interacting with CsWRKY13, thereby facilitating lignin biosynthesis in tea plants. Compared with the expression of CsWRKY13 alone, the co-expression of CsPAT1 and CsWRKY13 in Oryza sativa significantly increased lignin biosynthesis. Conversely, compared with the expression of CsPAT1 alone, the co-expression of CsPAT1 and CsWRKY13 in O. sativa significantly reduced lignin accumulation. These results demonstrated the antagonistic regulation of the lignin biosynthesis pathway by CsPAT1 and CsWRKY13. These findings improve our understanding of lignin biosynthesis mechanisms in tea plants and provide insights into the role of the GRAS transcription factor family in lignin accumulation., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Transcription factors (TFs) specifically bind to DNA, recruit cofactor proteins and modulate target gene expression, rendering them essential roles in the regulation of numerous biological processes. Meanwhile, mutated or dysregulated TFs are involved in a variety of human diseases. As multiple signaling pathways ultimately converge at TFs, targeting these TFs directly may prove to be more specific and cause fewer side effects, than targeting the upfront conventional targets in these pathways. All these features together endue TFs with great potential and high selectivity as therapeutic drug targets. However, TFs have been historically considered "undruggable", mainly due to their lack of structural information, especially about the appropriate ligand-binding sites and protein-protein interactions, leading to relatively limited choices in the TF-targeting drug design. In this review, we summarize the recent progress of TF-targeting drugs and highlight certain strategies used for targeting TFs, with a number of representative drugs that have been approved or in the clinical trials as examples. Various approaches in targeting TFs directly or indirectly have been developed. Common direct strategies include aiming at defined binding pockets, proteolysis-targeting chimaera (PROTAC), and mutant protein reactivation. In contrast, the indirect ones comprise inhibition of protein-protein interactions between TF and other proteins, blockade of TF expression, targeting the post-translational modifications, and targeting the TF-DNA interactions. With more comprehensive structural information about TFs revealed by the powerful cryo-electron microscopy technology and predicted by machine-learning algorithms, plus more efficient compound screening platforms and a deeper understanding of TF-disease relationships, the development of TF-targeting drugs will certainly be accelerated in the near future., (© 2022. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

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., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Flavonoids are secondary metabolites that play important roles in the entire tea plant life cycle and have potential health-promoting properties. MYB transcription factors (TFs) are considered potentially important regulators of flavonoid biosynthesis in plants. However, the molecular mechanisms by which MYB TFs regulate the flavonoid pathway in tea plant remain unknown., Results: In this study, two R2R3-MYB TFs (CsMYB2 and CsMYB26) involved in flavonoid biosynthesis in tea plant were investigated. The genes encoding CsMYB2 and CsMYB26 were cloned from the tea plant cultivar 'Longjing 43'. Phylogenetic analysis showed that CsMYB2 and CsMYB26 were grouped into the proanthocyanidin biosynthesis-related MYB clade. Multiple sequence alignment revealed that conserved motif 1 in the two MYB factors was related to the bHLH TF. Subcellular localization assays suggested that CsMYB2 localized in the nucleus. Promoter analysis indicated that CsMYB2, CsMYB26 and the related structural genes contain MYB recognition elements. The expression levels of the CsMYB2 and CsMYB26 genes and the structural genes in the flavonoid biosynthesis pathway were determined in leaves from various sites in the two tea plant cultivars 'Longjing 43' and 'Baiye 1 hao'., Conclusions: The expression levels of these genes were correlated with the accumulated flavonoid content. The results demonstrated that the expression level of CsF3'H may be regulated by CsMYB2 and that CsMYB26 expression is positively correlated with CsLAR expression. The relative transcriptional level of CsMYB26 may be the main reason for the different epigallocatechin contents between the tea plant cultivars 'Longjing 43' and 'Baiye 1 hao'. Our results will serve as a reference for the potential regulatory roles of CsMYB2 and CsMYB26 in flavonoid biosynthesis in tea plant and may also assist biologists in improving tea quality.

GRAS proteins are important transcription factors that play multifarious roles in regulating the growth and development as well as stress responses of plants. Tea plant is an economically important leaf -type beverage crop. Information concerning GRAS family transcription factors in tea plant is insufficient. In this study, 52 CsGRAS genes encoding GRAS proteins were identified from tea plant genome database. Phylogenetic analysis of the identified GRAS proteins from tea plant, Arabidopsis, and rice divided these proteins into at least 13 subgroups. Conserved motif analysis revealed that the gene structure and motif compositions of the proteins were considerably conserved among the same subgroup. Functional divergence analysis indicated that the shifted evolutionary rate might act as a major evolutionary force driving subfamily-specific functional diversification. Transcriptome analysis showed that the transcriptional levels of CsGRAS genes under non-stress conditions varied among different tea plant cultivars. qRT-PCR analysis revealed tissue and development stage-specific expression patterns of CsGRAS genes in tea plant. The expression patterns of CsGRAS genes in response to abiotic stresses and gibberellin treatment suggested the possible multiple functions of these genes. This study provides insights into the potential functions of GRAS genes.

Tea plant (Camellia sinensis (L.) O. Kuntze) is an important leaf-type woody crop used for producing of non-alcoholic beverages worldwide. The GROWTH-REGULATING FACTOR (GRF) transcription factors cooperated with GRF-INTERACTING FACTOR (GIF) transcriptional coactivators positively regulate leaf development. In the present study, six GRF and two GIF genes were identified and characterized in the leaf transcriptome of C. sinensis, respectively. The alignment results showed that the feature structures of the predicted homologous GRF and GIF proteins of C. sinensis hold a high identity with Arabidopsis and rice. The presence of C. sinensis miR396 target sites suggested that these miR396 members are the potential post-transcriptional regulators of CsGRF genes. The expression profiles of CsGRF and CsGIF1 genes were higher in tender leaves and consistently downregulated during tea plant leaf development. Those results suggested that these genes may be actively involved in the early stage leaf tissue formation in tea plant. The divergence of CsGRF and CsGIF genes in response to different hormonal stimuli revealed the possible multiple functions of these genes in hormonal regulation. This study provided the potential molecular basis of the CsGRF and CsGIF family genes for future functional research on leaf development and hormonal stimuli in C. sinensis.

Tea plant [Camellia sinensis (L.) O. Kuntze] is a leaf-type healthy non-alcoholic beverage crop, which has been widely introduced worldwide. Tea is rich in various secondary metabolites, which are important for human health. However, varied climate and complex geography have posed challenges for tea plant survival. The WRKY gene family in plants is a large transcription factor family that is involved in biological processes related to stress defenses, development, and metabolite synthesis. Therefore, identification and analysis of WRKY family transcription factors in tea plant have a profound significance. In the present study, 50 putative C. sinensis WRKY proteins (CsWRKYs) with complete WRKY domain were identified and divided into three Groups (Group I-III) on the basis of phylogenetic analysis results. The distribution of WRKY family transcription factors among plantae, fungi, and protozoa showed that the number of WRKY genes increased in higher plant, whereas the number of these genes did not correspond to the evolutionary relationships of different species. Structural feature and annotation analysis results showed that CsWRKY proteins contained WRKYGQK/WRKYGKK domains and C2H2/C2HC-type zinc-finger structure: D-X18-R-X1-Y-X2-C-X4-7-C-X23-H motif; CsWRKY proteins may be associated with the biological processes of abiotic and biotic stresses, tissue development, and hormone and secondary metabolite biosynthesis. Temperature stresses suggested that the candidate CsWRKY genes were involved in responses to extreme temperatures. The current study established an extensive overview of the WRKY family transcription factors in tea plant. This study also provided a global survey of CsWRKY transcription factors and a foundation of future functional identification and molecular breeding.

In vascular plants, heat shock transcription factors (Hsfs) regulate heat stress response by regulating the expression of heat shock proteins. This study systematically and comprehensively analyzed the Hsf family in tea plant [Camellia sinensis (L.) O. Kuntze]. A total of 16 CsHsfs were identified from the transcriptome database of tea plant and analyzed for their phylogenetic relationships, motifs, and physicochemical characteristics. On the basis of the phylogenetic comparison of tea plant with Arabidopsis thaliana, Populus trichocarpa, Theobroma cacao, and Oryza sativa, the CsHsfs were classified into three classes, namely, A (56.25%), B (37.50%), and C (6.25%). Heat mapping showed that the expression profiles of CsHsf genes under non-stress conditions varied among four tea plant cultivars, namely, 'Yunnanshilixiang', 'Chawansanhao', 'Ruchengmaoyecha', and 'Anjibaicha'. Six CsHsf genes (CsHsfA1a, CsHsfA1b, CsHsfA6, CsHsfB1, CsHsfB2b, and CsHsfC1) were selected from classes A, B, and C to analyze the expression profiles of CsHsf genes through quantitative real-time PCR in 'Yingshuang', 'Anjibaicha', and 'Yunnanshilixiang' under high (38 °C) or low (4 °C) temperature stress. Temperature stress positively or negatively regulated all of the selected CsHsf genes, and the expression levels evidently varied even among CsHsf genes belonging to the same class. This study provided a relatively detailed summary of Hsfs in tea plant and may serve as a reference for further studies on the mechanism of temperature stress regulation by CsHsfs., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Chinese cabbage (Brassica rapa subsp. pekinensis) is among the most important vegetables and is widely cultivated in world. Genes in the AP2/ERF family encode transcriptional regulators that serve a variety of functions in the plants. Expressed sequence tags (ESTs) are created by partially sequencing randomly isolated gene transcripts and have proved valuable in molecular biology. Starting from the database with 142 947 ESTs of B. rapa, 62 putative AP2/ERF family genes were identified by in silico cloning using the conserved AP2/ERF domain amino acid sequence of Arabidopsis thaliana as a probe. Based on the number of AP2/ERF domains and functions of the genes, the AP2/ERF transcription factors from B. rapa were classified into four subfamilies (DREB, ERF, AP2 and RAV). Using large-scale available EST information as a source of expression data for digital expression profiling, differentially detected genes were identified among diverse plant tissues. Roots contained the largest number of transcripts of the AP2/ERF family genes, followed by leaves and seeds. Only a few of the 62 AP2/ERF family genes were detected in all tissues: most were detected only in some tissues but not in others. The maximum detected was that of BraERF-B2-5, and it was recorded from seed tissue.

Populus is a model system for investigating the wood development, crown formation, and disease resistance in perennial plants. AR2/ERF is a large family of transcription factors in plant, encoding transcriptional regulators with a variety of functions involved in the developmental and physiological processes. Here, starting from database of Populus genome, we identified 200 AP2/ERF genes by in silico cloning method using the AP2/ERF conserved domain amino acid sequence of Arabidopsis thaliana as probe. Based on the number of AP2/ERF domains and the function of the genes, those AP2/ERF genes from Populus were classified into four subfamilies named the AP2, DREB, ERF, RAV, and a soloist. Among these genes, the number genes of total AP2/ERF family genes, DREB subfamily, and ERF subfamily from Populus trichocarpa were about 1.4-1.6-fold than those from A. thaliana. The rates were very similar for the putative homologs between Populus and Arabidopsis.

Background & Objective: Molecular biological studies indicated that abnormal expression of cyclooxygenase-2(COX-2), p53, proliferating cell nuclear antigen(PCNA), and nm23 correlate with the development of gastric cancer, but the relationship between abnormal expression of above gene proteins and the biological behavior of gastric cancer was not yet clear. This study was designed to investigate the relationship between expressions of COX-2, p53, PCNA, and nm23 and the clinicopathological behavior in gastric cancer., Methods: The expressions of COX-2, p53, PCNA, and nm23 were detected by using immunohistochemical(SP) method., Results: (1) The overexpression rate of COX-2 in gastric cancer was 70.4% (50/71), and the overexpression of COX-2 was correlated to tumor size, gross morphology, histological type, lymph node metastases, and clinicopathological stage of gastric cancer (P < 0.05, or P < 0.01). (2) The overexpression rates of p53 and PCNA in 71 surgically removed specimens from the patients with gastric cancer were 74.6% and 78.9%, respectively. And the expressions of p53 (86.7%) and PCNA (88.8%) in gastric cancer patients with lymph node metastasis were significantly higher than those in patients without lymph node metastasis (53.8% and 61.5%) (both, P < 0.05), respectively. Moreover, expressions of p53(52.2%) and PCNA(60.9%) in stage I + II patients were lower than those(85.4% and 87.5%) in stage III + IV (both, P < 0.05). (3) The low-expression of nm23 in gastric cancer was 71.8%, and its low-expression rate of nm23 in patients without lymph node metastasis(88.5%) and in stage I + II (91.3%) were much higher than those in the patients with lymph node metastasis (62.2%) and in stage III + IV (62.5%) (respectively, P < 0.05). (4) The differences of histological types, depth of invasion, lymph node metastasis and clinical stage were significantly different(P < 0.05 or P < 0.001), between the patients with two or more genes expression of COX-2, p53, PCNA, and nm23 and those with less one gene expression., Conclusion: Our results suggest that abnormal expressions of COX-2, p53, PCNA, and nm23 associate with malignant potential, lymph node metastasis and clinical stage, and they might therefore play a role in development of gastric cancer.

The BRASSINAZOLE-RESISTANT (BZR1) transcription factor family is a key transcription factor downstream of the brassinosteroid (BR) signaling pathway that plays a critical role in plant growth and resistance to environmental stress. Tea plant (Camellia sinensis) is a perennial plant with important economic value. In this study, a total of 5, 6, 7, 8, and 7 CsBZR1s were identified from the genomes of wild tea plant ('DASZ') and four tea cultivars ('Longjing 43,' 'Shuchazao,' 'Tieguanyin,' and 'Huangdan'), respectively. The phylogenetic tree analysis classified the 33 CsBZR1s into four groups, with members in the same classification having similar conserved motifs. Covariance and gene structure analysis revealed that two CsBZR1 genes (DACsBZR1.1, DACsBZR1.4) have high sequence alignment rates among the five tea genomes. One unique CsBZR1 gene present in each of 'DASZ,' 'Longjing 43,' 'Shuchazao,' and 'Huangdan.' In comparison, 'Tieguanyin' has three specific CsBZR1 genes. The upstream promoter sequences of 33 CsBZR1 genes contain many regulatory elements associated with hormone and stress responses. The expression levels of lj43CsBZR1s and sczCsBZR1s in different tissues of tea plants were significantly different. Under hormonal (GA, ABA, and BR) and abiotic stress (cold, heat, drought, and salt) treatments, most lj43CsBZR1s and sczCsBZR1s showed up-regulation in their expression levels. The relative expression levels of lj43CsBZR1s and sczCsBZR1s under GA and heat treatments were significantly higher than those under other treatments. This study provided a potential theoretical basis for the analysis of the function of CsBZR1 protein and its regulatory mechanism in response to hormone and abiotic stress in tea plants. [ABSTRACT FROM AUTHOR]

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]

Previous studies have indicated that Brca1 (Breast cancer suppressor gene 1) plays an important role in neural development and degenerative diseases. However, the bioactivity and regulatory mechanism of Brca1 expression in retinal neurocytes remain unclear. In the present study, our data indicated that Brca1 maintains the state of neuronal precursor cells. Brca1 silencing induces differentiation in 661W cells. Nestin, a marker of precursor cells, was significantly decreased in parallel with Brca1 silencing in 661W cells, whereas Map2 (Microtubule associated protein 2), a marker of differentiated neurons, was significantly increased. Neurite outgrowth was increased by ~4.0-fold in Brca1-silenced cells. Moreover, DNA affinity purification assays and ChIP assays demonstrated that Gata3 (GATA binding protein 3) regulates Brca1 transcription in 661W cells. Silencing or overexpressing Gata3 could significantly regulate the expression of Brca1 and affect its promoter inducibility. Furthermore, the expression of Gata3 generally occurred in parallel with that of Brca1 in developing mouse retinas. Both Gata3 and Brca1 are expressed in the neonatal mouse retina but are developmentally silenced with age. Exogenous Gata3 significantly inhibited neural activity by decreasing synaptophysin and neurite outgrowth. Thus, this study demonstrated that Brca1 is transcriptionally regulated by Gata3. Brca1/Gata3 silencing is involved in neuronal differentiation and maturation. [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]

SQUAMOSA promoter binding protein (SBP)-box proteins are plant-specific transcription factors (TFs) and play crucial roles in a variety of physiological processes, including plant growth and development, signal transduction, and stress response. However, SBP-box family genes have not been well characterized in tea plant. In the present study, we identified 16 CsSBP genes in tea plant based on the tea plant genomic data. Phylogenetic analysis of SBP-box proteins from tea plant, Arabidopsis, and rice divided these proteins into nine groups (A–I). The number of exon–intron varied among the groups. The SBP-box genes in a same group shared similar exon–intron structures and motif locations. Prediction of miRNA target sites revealed that six CsSBPs genes contained a miR156 target site, while seven were targeted by miR157. RT-qPCR analysis revealed tissue/organ-specific expression patterns of CsSBP genes. In addition, their expression patterns in response to different phytohormone treatments and abiotic stresses were also investigated. This work provides base foundation for understanding the crucial roles of CsSBP genes in plant development and other biological processes. [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]

Abiotic stresses, including extreme temperature, drought and salinity, seriously threaten the growth and development of tea plants. The tea plant fights against various threats to innate defensive systems by regulating the expression profiles of related anti-genes. R2R3-type MYB family transcription factors (TFs) contribute to plant defense against abiotic stresses. Five CsMYB TFs were identified from the tea plant according to the transcriptome database. Conserved motif analysis revealed that subgroups 20 and 22 were conserved in the N-terminus with two motifs. All five CsMYB TF sequence homologies had a flexible C-terminal region. Subcellular localization analysis indicated that the protein of CsMYB19 was specifically localized in the nucleus. The expression patterns of CsMYB genes under abiotic stress treatments were significantly higher than that of the control, and the members from subgroup 20 had higher response than those in subgroup 22. During hormonal treatment, CsMYB8 was selected as highly responsive to methyl jasmonate (MeJA) treatment. The expression level of CsMYB20 was highest under ABA treatment and lowest under SA treatment. Our study serves as a foundation for understanding the response mechanisms of MYB genes under abiotic stress in tea plants. [ABSTRACT FROM AUTHOR]

In plants, the NAC (NAM-ATAF1/2-CUC) family of proteins constitutes several transcription factors and plays vital roles in diverse biological processes, such as growth, development, and adaption to adverse factors. Tea, as a non-alcoholic drink, is known for its bioactive ingredients and health efficacy. Currently, knowledge about NAC gene family in tea plant remains very limited. In this study, a total of 45 CsNAC genes encoding NAC proteins including three membrane-bound members were identified in tea plant through transcriptome analysis. CsNAC factors and Arabidopsis counterparts were clustered into 17 subgroups after phylogenetic analysis. Conserved motif analysis revealed that CsNAC proteins with a close evolutionary relationship possessed uniform or similar motif compositions. The distribution of NAC family MTFs (membrane-associated transcription factors) among higher plants of whose genome-wide has been completed revealed that the existence of doubled TMs (transmembrane motifs) may be specific to fabids. Transcriptome analysis exhibited the expression profiles of CsNAC genes in different tea plant cultivars under non-stress conditions. Nine CsNAC genes, including the predicted stress-related and membrane-bound genes, were examined through qRT-PCR (quantitative real time polymerase chain reaction) in two tea plant cultivars, namely, ‘Huangjinya’ and ‘Yingshuang’. The expression patterns of these genes were investigated in different tissues (root, stem, mature leaf, young leaf and bud) and under diverse environmental stresses (drought, salt, heat, cold and abscisic acid). Several CsNAC genes, including CsNAC17 and CsNAC30 that are highly orthologous to known stress-responsive ANAC072/RD26 were identified as highly responsive to abiotic stress. This study provides a global survey of tea plant NAC proteins, and would be helpful for the improvement of stress resistance in tea plant via genetic engineering. [ABSTRACT FROM AUTHOR]

The AP2/ERF transcription factors of higher plants regulate transcriptional networks that control development and responses to biotic and abiotic stresses. In this study, the rice OsAP23 gene, which encodes an AP2/ERF transcription factor, was isolated from rice using a yeast-one-hybrid system. The OsAP23 transcription factor belongs to the B3 group of the ERF subfamily. Germination results for transgenic Arabidopsis plants hosting the OsAP23 gene revealed greater inhibition at the germination and seedling stages with increasing concentration of NaCl compared to the wild-type plants. Exogenous ABA also reduced the rate of germination of transgenic Arabidopsis seeds that over-express OsAP23 compared with wild-type Arabidopsis seeds. In addition, following exposure to high salt concentrations, several stress-responsive regulatory genes were induced to a significantly greater extent in the wild-type lines compared with lines that over-express OsAP23. These results suggested that OsAP23 might be a negative regulator of the salt stress response in higher plants. [ABSTRACT FROM AUTHOR]

The AP2/ERF family transcription factors (TFs) act as the nodes of a regulatory network in a plant's response to abiotic and biotic stress. AP2-like genes from apple ( Malus × domestica Borkh), one of the most widely cultivated fruit trees worldwide, were identified and analysed in order to understand the transcriptional regulation through the AP2/ERF family TFs. Starting from the M. domestica database, 58 AP2-like TFs were identified by in silico cloning using the AP2/ERF TFs amino acid sequence of Arabidopsis thaliana as a probe. The AP2/ERF TFs from apple were classified into four subfamilies, DREB, ERF, AP2 and RAV. To establish detailed expression data of this gene family in apple, six kinds of tissue (bud, flower, fruit, leaf, root and stem) and cell culture were examined for the presence of AP2-like genes. Most of the apple AP2-like genes indicate some degree of tissue specificity and were most abundant in root followed by stem, and expression levels were low in leaf and in bud. [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]

Abstract: Lithium chloride is a therapeutic agent for treatment of bipolar affective disorders. Increasing numbers of studies have indicated that lithium has neuroprotective effects. However, the molecular mechanisms underlying the actions of lithium have not been fully elucidated. This study aimed to investigate whether lithium chloride produces neuroprotective function by improving DNA repair pathway in retinal neurocyte. In vitro, the primary cultured retinal neurocytes (85.7% are MAP-2 positive cells) were treated with lithium chloride, then cultured with serum-free media to simulate the nutrient deprived state resulting from ischemic insult. The neurite outgrowth of the cultured cells increased significantly in a dose-dependent manner when exposed to different levels of lithium chloride. Genomic DNA electrophoresis demonstrated greater DNA integrity of retinal neurocytes when treated with lithium chloride as compared to the control. Moreover, mRNA and protein levels of Ligase IV (involved in DNA non-homologous end-joining (NHEJ) pathway) in retinal neurocytes increased with lithium chloride. The end joining activity assay was performed to determine the role of lithium on NHEJ in the presence of extract from retinal neurocytes. The rejoining levels in retinal neurocytes treated with lithium were significantly increased as compared to the control. Furthermore, XRCC4, the Ligase IV partner, and the transcriptional factor, CREB and CTCF, were up-regulated in retinal cells after treating with 1.0mM lithium chloride. Therefore, our data suggest that lithium chloride protects the retinal neural cells from nutrient deprivation in vitro, which may be similar to the mechanism of cell death in glaucoma. The improvement in DNA repair pathway involving in Ligase IV might have an important role in lithium neuroprotection. This study provides new insights into the neural protective mechanisms of lithium chloride. [Copyright &y& Elsevier]

Following publication of the original article [1], the author reported that there was a mismatch between figures and their legends. [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]