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Safflower (Carthamus tinctorius L.), a versatile medicinal and economic crop, harbors untapped genetic resources essential for stress resilience and metabolic regulation. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors, exclusive to plants, are pivotal in orchestrating growth, development, and stress responses, yet their roles in safflower remain unexplored. Here, we report the comprehensive identification and characterization of 26 safflower TCP genes (CtTCPs), categorized into Class I (PROLIFERATING CELL FACTOR, PCF) and Class II (CINCINNATA and TEOSINTE BRANCHED1/CYCLOIDEA, CIN and CYC/TB1) subfamilies. Comparative phylogenetics, conserved motif, and gene structure analyses revealed a high degree of evolutionary conservation and functional divergence within the gene family. Promoter analyses uncovered light-, hormone-, and stress-responsive cis-elements, underscoring their regulatory potential. Functional insights from qRT-PCR analyses demonstrated dynamic CtTCP expression under abiotic stresses, including abscisic acid (ABA), Methyl Jasmonate (MeJA), Cold, and ultraviolet radiation b (UV-B) treatments. Notably, ABA stress triggered a significant increase in flavonoid accumulation, correlated with the upregulation of key flavonoid biosynthesis genes and select CtTCPs. These findings illuminate the complex regulatory networks underlying safflower's abiotic stress responses and secondary metabolism, offering a molecular framework to enhance crop resilience and metabolic engineering for sustainable agriculture [ABSTRACT FROM AUTHOR]

TCP is a plant-specific transcription factor that plays an important role in plant growth and development. In this study, we used bioinformatics to identify the entire genome of the TCP gene family in Glycyrrhiza inflata Bat, and we analyzed the expression characteristics of GiTCP genes under UV-B radiation using qRT-PCR. The results were as follows: (1) 24 members of the TCP gene family were identified in G. inflata, evenly distributed on its 24 chromosomes. (2) The GiTCP genes contained 0–4 introns and 0–5 exons. (3) The GiTCP genes were phylogenetically divided into three subfamilies—PCF, CIN, and CYC/TB1, with 14, 9, and 1 GiTCP proteins, respectively. (4) A covariance analysis showed that two pairs of GiTCP genes underwent a fragmentary duplication event. (5) A cis-element analysis showed that the cis-responsive elements of the GiTCP genes' promoter regions were mainly comprised of light-responsive, stress-responsive, hormone-regulated, growth and development, and metabolic-regulated elements. (6) A protein network interaction analysis revealed a total of 14 functional molecules of TCPs and 8 potential interacting proteins directly related to GiTCP proteins. (7) GO annotation showed that the GiTCP genes were mainly enriched in BP, CC, and MF groups and had corresponding functions. (8) RNA-seq and qRT-PCR further indicated that GiTCP3, 6, 7, 8, 12, 14, 17, 23, and 24 were up- or down-regulated in G. inflata after UV-B radiation, demonstrating that these genes responded to UV-B radiation in G. inflata. (9) Subcellular localization analysis showed that the GiTCP8 protein was localized in the nucleus. The results of this study provide a basis for further exploration of the function of the GiTCP gene family in the growth and development of G. inflata. [ABSTRACT FROM AUTHOR]

Summary: Fate determination is indispensable for the accurate shaping and specialization of plant organs, a process critical to the structural and functional diversity in plant kingdom. The TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family of transcription factors has been recognized for its significant contributions to plant organogenesis and morphogenesis. Recent research has shed light on the pivotal roles that TCPs play in fate determination. In this review, we delve into the current understanding of TCP functions, emphasizing their critical influence on fate determination from the organelle to the cell and organ levels. We also consolidate the molecular mechanisms through which TCPs exert their regulatory effects on fate determination. Additionally, we highlight intriguing points of TCPs that warrant further exploration in future research endeavors. [ABSTRACT FROM AUTHOR]

Phytoplasmas are obligate intracellular pathogens that profoundly modify the development, physiology and behavior of their hosts by secreting effector proteins that disturb signal pathways and interactions both in plant and insect hosts. The characterization of effectors and their host-cell targets was performed for only a few phytoplasma species where it was shown that the SAP11 effector alters plant morphology by destabilizing plant transcription factors: TEOSINTE BRANCHED 1-CYCLOIDEA-PROLIFERATING CELL FACTOR (TCPs). To explore the possible role of the SAP11-like effector from 'Ca. P. solani', we used Arabidopsis thaliana as a model plant. The SAP11-like effector gene from 'Ca. P. solani' was introduced into arabidopsis by floral dip and transgenic lines were regenerated. In planta bimolecular fluorescence complementation (BIFC) assays in agroinfiltrated Nicotiana benthamiana leaf cells were conducted to detect interactions between SAP11-like and AtTCP2 and AtTCP4 using confocal microscopy. SAP11-like from 'Ca. P. solani' induced significant phenotypic changes in arabidopsis, including crinkled leaves with reduced size, lower biomass, more axillary branches, changes in root morphology, and crinkled and smaller siliques. The BIFC assays proved in planta interaction of SAP11-like effector with AtTCP2 and AtTCP4. To our knowledge, this is the first characterization of the interaction between the 'Ca. P. solani' effector and plant transcription factors, suggesting a potential mechanism of modulating plant development and induction of characteristic symptoms in 'Ca. P. solani'-infected plants. [ABSTRACT FROM AUTHOR]

Passion fruit is a valued tropical fruit crop that faces environment-related growth strains. TCP genes are important for both growth modulation and stress prevention in plants. Herein, we systematically analyzed the TCP gene family in passion fruit, recognizing 30 members. Genes exhibiting closer phylogenetic relationships exhibited similar protein and gene structures. Gene members of the TCP family showed developmental-stage- or tissue-specific expression profiles during the passion fruit life cycle. Transcriptome data also demonstrated that many PeTCPs showed induced expression in response to hormonal treatments and cold, heat, and salt stress. Based on transcriptomics data, eight candidate genes were chosen for preferential gene expression confirmation under cold stress conditions. The qRT-PCR assays suggested PeTCP15/16/17/19/23 upregulation, while PeTCP1/11/25 downregulation after cold stress. Additionally, TCP19/20/29/30 exhibited in silico binding with cold-stress-related miRNA319s. GFP subcellular localization assays exhibited PeTCP19/1 were localized at the nucleus. This study will aid in the establishment of novel germplasm, as well as the further investigation of the roles of PeTCPs and their cold stress resistance characteristics. [ABSTRACT FROM AUTHOR]

Summary: Shoot branching is determined by a balance between factors that promote axillary bud dormancy and factors that release buds from the quiescent state. The TCP family of transcription factors is classified into two classes, Class I and Class II, which usually play different roles. While the role of the Class II TCP BRANCHED1 (BRC1) in suppressing axillary bud development in Arabidopsis thaliana has been widely explored, the function of Class I TCPs in this process remains unknown.We analyzed the role of Class I TCP14 and TCP15 in axillary branch development in Arabidopsis through a series of genetic and molecular studies.In contrast to the increased branch number shown by brc1 mutants, tcp14 tcp15 plants exhibit a reduced number of branches compared with wild‐type. Our findings provide evidence that TCP14 and TCP15 act by counteracting BRC1 function through two distinct mechanisms. First, they indirectly reduce BRC1 expression levels. Additionally, TCP15 directly interacts with BRC1 decoying it from chromatin and thereby preventing the transcriptional activation of a set of BRC1‐dependent genes.We describe a molecular mechanism by which Class I TCPs physically antagonize the action of the Class II TCP BRC1, aligning with their opposite roles in axillary bud development. [ABSTRACT FROM AUTHOR]

TCP is a plant-specific transcription factor that plays crucial roles in plant growth and development. In this study, bioinformatics methods were used to identify the complete genome of tartary buckwheat TCP family, and real-time fluorescence quantitative PCR(qRT-PCR)analysis was conducted to investigate the expression characteristics of TCP gene under drought and salt stresses. The results were as follows:(1)A total of 28 TCP family members were identified in the tartary buckwheat genome, unevenly distributed across its eight chromosomes. (2)Most tartary buckwheat TCP genes contained 1-5 exons. (3)Phylogenetic analysis classified the tartary buckwheat TCP family into five clades, with intraspecific TCP proteins mainly clustering together. (4)Collinearity analysis indicated that there were five tartary buckwheat TCP genes originated from genome-wide replication events. (5)Cis-element analysis revealed that the promoter regions of tartary buckwheat TCP genes predominantly contained two types of cis-response elements as stress response elements and hormone response elements. (6)Transcriptomic data analysis demonstrated that all tartary buckwheat TCP genes were expressed in the examined tissues. (7)qRT-PCR results indicated that the expression levels of FtTCP3, FtTCP6, FtTCP12, and FtTCP13 changed under drought stress and salt stress conditions, with FtTCP3 peaking at 6 h of drought and salt treatments, suggesting that it plays a positive regulatory role in tartary buckwheat's response to drought stress and salt stress. This study provides new insights into the evolution and function of the TCP gene family, and provides a reference for the functional exploration and utilization of the tartary buckwheat TCP gene family. [ABSTRACT FROM AUTHOR]

Uncaria rhynchophylla is a widely used Chinese herbal medicine known for its terpenoid indole alkaloids (TIAs), which help in treating hypertension. Teosinte branched 1/cycloidea/proliferating cell factors 1/2 (TCP) TFs have been shown to have a role in the growth and development of plants, but the regulation mechanism of UrTCP in the TIAs biosynthesis pathway is yet unknown. In this study, twenty-six UrTCP genes were identified from the genome of U. rhynchophylla, and these genes were classified into three subgroups based on the phylogenetic analysis. UrTCPs from the same group or subgroup share comparable gene structures and conserved motifs. These 26 UrTCP genes were unevenly distributed throughout 22 chromosomes, and gene segmental duplication occurred. The interspecific co-linearity analysis suggested that UrTCP4 may have an important function in evolutionary process. The expression patterns analysis of UrTCP genes by RT-qPCR showed most UrTCP genes had the highest expression in leaves and stem hooks. The results of co-expression analysis and phylogenetic relationships screened UrTCP4 as the most likely participant in TIAs and its precursor synthesis. Furthermore, the subcellular localization of UrTCP4 indicated that it is located in nucleus. Dual luciferase assays revealed the UrTCP4 protein could activate or repress the transcription of UrLAMT and Ur7-DLH in the TIAs synthesis pathway. Finally, Yeast-one-hybrid assays demonstrated that the UrTCP4 protein can bind to the promoters of UrLAMT and Ur7-DLH. Thus, UrTCP4 may be involved in the regulation of the TIAs biosynthesis pathway. This research establishes a groundwork for elucidating the functions of UrTCP gene family in U. rhynchophylla, offering new insights into the regulation of TIAs.

TEOSINTE-BRANCHED/CYCLOIDEA/PCF (TCP) proteins are plant-specific transcription factors (TFs) that play a pivotal role in leaf development by controlling cell proliferation and differentiation. In this study, the authors systematically analyzed the phylogeny, sequence structure, domain feature and expression profiles of TCP genes in Liriodendron chinense, an ornamental tree species with peculiar leaf shape. A total of 17 LcTCP genes were identified in L. chinense genome, which could be grouped into two classes according to their features in the TCP domain. RT-qPCR analysis showed that the expression levels of four TCP genes in Class I (LcTCP21, LcTCP9, LcTCP19a, and LcTCP19b) and three genes in Class II (LcTCP4a, LcTCP4b, and LcTCP24) were consistently higher than those of the other LcTCP genes during leaf development. Degradome data analysis revealed that three LcTCP genes, LcTCP4a, LcTCP4b, and LcTCP24, are targeted by lch-miR319c. Further, LcTCP4a/b and LcTCP24 differed significantly in their expression levels between leaf buds and lobed leaves. However, the expression patterns of LcTCP21 and LcTCP9 contrasted with those of LcTCP19a and LcTCP19b, implying that leaf development in L. chinense may be regulated by a balance between the antagonistic roles of Class I and Class II LcTCP genes. Furthermore, overexpression of LcTCP4 in Arabidopsis thaliana caused a tendency of leaf margin smoothness, and down-regulated the expression levels of genes involved in cell division, AtCYCD3,1 and AtKNOLLE, indicating that LcTCP4 may influence leaf margin shape by inhibiting cell proliferation. Overall, this study provided a comprehensive assessment of the LcTCP gene family and serves as a cornerstone for subsequent functional verification of the LcTCP genes in regulating the leaf development of L. chinense. [ABSTRACT FROM AUTHOR]

Plant structure has a large influence on crop yield formation, with branching and plant height being the important factors that make it up. We identified a gene, MtTCP18, encoding a TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor highly conserved with Arabidopsis gene BRC1 (BRANCHED1) in Medicago truncatula. Sequence analysis revealed that MtTCP18 included a conserved basic helix–loop–helix (BHLH) motif and R domain. Expression analysis showed that MtTCP18 was expressed in all organs examined, with relatively higher expression in pods and axillary buds. Subcellular localization analysis showed that MtTCP18 was localized in the nucleus and exhibited transcriptional activation activity. These results supported its role as a transcription factor. Meanwhile, we identified a homozygous mutant line (NF14875) with a mutation caused by Tnt1 insertion into MtTCP18. Mutant analysis showed that the mutation of MtTCP18 altered plant structure, with increased plant height and branch number. Moreover, we found that the expression of auxin early response genes was modulated in the mutant. Therefore, MtTCP18 may be a promising candidate gene for breeders to optimize plant structure for crop improvement. [ABSTRACT FROM AUTHOR]

Phytoplasmas are obligate intracellular pathogens that profoundly modify the development, physiology and behavior of their hosts by secreting effector proteins that disturb signal pathways and interactions both in plant and insect hosts. The characterization of effectors and their host-cell targets was performed for only a few phytoplasma species where it was shown that the SAP11 effector alters plant morphology by destabilizing plant transcription factors: TEOSINTE BRANCHED 1-CYCLOIDEA-PROLIFERATING CELL FACTOR (TCPs). To explore the possible role of the SAP11-like effector from ‘Ca. P. solani’, we used Arabidopsis thaliana as a model plant. The SAP11-like effector gene from ‘Ca. P. solani’ was introduced into arabidopsis by floral dip and transgenic lines were regenerated. In planta bimolecular fluorescence complementation (BIFC) assays in agroinfiltrated Nicotiana benthamiana leaf cells were conducted to detect interactions between SAP11-like and AtTCP2 and AtTCP4 using confocal microscopy. SAP11-like from ‘Ca. P. solani’ induced significant phenotypic changes in arabidopsis, including crinkled leaves with reduced size, lower biomass, more axillary branches, changes in root morphology, and crinkled and smaller siliques. The BIFC assays proved in planta interaction of SAP11-like effector with AtTCP2 and AtTCP4. To our knowledge, this is the first characterization of the interaction between the ‘Ca. P. solani’ effector and plant transcription factors, suggesting a potential mechanism of modulating plant development and induction of characteristic symptoms in ‘Ca. P. solani’-infected plants.

TCP transcription factors play a key role in regulating various developmental processes, particularly in shoot branching, flower development, and leaf development, and these factors are exclusively found in plants. However, comprehensive studies investigating TCP transcription factors in pepper (Capsicum annuum L.) are lacking. In this study, we identified 27 CaTCP members in the pepper genome, which were classified into Class I and Class II through phylogenetic analysis. The motif analysis revealed that CaTCPs in the same class exhibit similar numbers and distributions of motifs. We predicted that 37 previously reported miRNAs target 19 CaTCPs. The expression levels of CaTCPs varied in various tissues and growth stages. Specifically, CaTCP16, a member of Class II (CIN), exhibited significantly high expression in flowers. Class I CaTCPs exhibited high expression levels in leaves, while Class II CaTCPs showed high expression in lateral branches, especially in the CYC/TB1 subclass. The expression profile suggests that CaTCPs play specific roles in the developmental processes of pepper. We provide a theoretical basis that will assist in further functional validation of the CaTCPs. [ABSTRACT FROM AUTHOR]

Passion fruit is a valued tropical fruit crop that faces environment-related growth strains. TCP genes are important for both growth modulation and stress prevention in plants. Herein, we systematically analyzed the TCP gene family in passion fruit, recognizing 30 members. Genes exhibiting closer phylogenetic relationships exhibited similar protein and gene structures. Gene members of the TCP family showed developmental-stage- or tissue-specific expression profiles during the passion fruit life cycle. Transcriptome data also demonstrated that many PeTCPs showed induced expression in response to hormonal treatments and cold, heat, and salt stress. Based on transcriptomics data, eight candidate genes were chosen for preferential gene expression confirmation under cold stress conditions. The qRT-PCR assays suggested PeTCP15/16/17/19/23 upregulation, while PeTCP1/11/25 downregulation after cold stress. Additionally, TCP19/20/29/30 exhibited in silico binding with cold-stress-related miRNA319s. GFP subcellular localization assays exhibited PeTCP19/1 were localized at the nucleus. This study will aid in the establishment of novel germplasm, as well as the further investigation of the roles of PeTCPs and their cold stress resistance characteristics.

Teosinte branched/Cycloidea/Proliferating cell factors (TCPs), a small transcription gene family, serve in developmental processes such as branching, flowering, and growth of plants. In this study, the TCP transcription gene family of eucalyptus, which is considered important for its medicinal and industrial uses, was bioinformatically investigated. A total of 16 Eucalyptus grandis TCP (Egra-TCP) genes were found to be distributed on chromosomes 1, 2, 4, 6, 7, 9, 10 and 11. Several segmentally-duplicated gene couples including Egra-TCP-7/Egra-TCP-11, -13 and -16, Egra-TCP-6/Egra-TCP-12 and -15, Egra-TCP-12/Egra-TCP-15 and Egra-TCP-11/Egra-TCP-13 were discovered. Egra-TCPs were divided into three main clades based on phylogenetic analysis, motif, and gene structure. While Egra-TCP-10 has the highest molecular weight with 47.19 kDa, the lowest was Egra-TCP-1 with 21.68 kDa. Twelve Egra-TCP genes were found to have no introns, while the Egra-TCP-7, -15, and -16 genes had a single intron. The orthologous relationships among E. grandis/Arabidopsis thaliana and E. grandis/Vitis vinifera were identified through a synteny analysis. Digital gene expression profiles of Egra-TCP genes in tissues such as xylem, phloem, shoot tips, young and mature leaf revealed a high expression pattern. The findings of this study contributes to existing knowledge in the biotechnology field by providing contributing to our understanding of the molecular basis of the TCP gene family in the eucalyptus plant.

TCP transcription factors are a type of plant-specific transcription factors, which have been implicated in multiple aspects of plant biological processes. To study the role of potato TCP transcription factors in response to low nitrogen fertilizer stress, here, four transcriptome libraries from potato roots and leaves under the conditions of low nitrogen fertilizer (0.05 mmol·L-1) and sufficient nitrogen fertilizer (7.5 mmol·L-1) were constructed for transcriptome sequencing, respectively. Meanwhile, the differentially expressed TCP transcription factor were analyzed. The results were as follows: (1) A total of 24 TCP transcription factors were identified in the four transcriptome libraries, and mainly distributed on the second, third and sixth chromosomes. (2) The analysis of domains showed that all of 24 transcription factors contained basic-Helix-Loop-Helix domain. (3) The phylogenetic analysis showed that the TCP proteins of potato and Arabidopsis thaliana were closely related, and clustered into ten subgroups. (4) Transcriptome sequencing results showed that the expression levels of most potato TCP transcription factors were suppressed by low nitrogen fertilizer stress. Among them, three TCP transcription factors were significantly differentially expressed in roots, while five TCP transcription factors were specifically expressed in leaves. (5) According to the GO functional analysis and the relationship between the potato and the A. thaliana TCP transcription factors, it is predicted that these TCP transcription factors were involved in response of potato to low nitrogen fertilizer stress. The research provides a foundation for further study on the molecular role of transcription factors in response to low nitrogen fertilizer stress in potato and other crops.

Petal size is a critical factor in plant reproduction and horticulture, and is largely determined by cell expansion. Gerbera hybrida is an important horticultural plant and serves as a model for studying petal organogenesis. We have previously characterized GhWIP2, a Trp-Ile-Pro (WIP)-type zinc protein, that constrains petal size by suppressing cell expansion. However, the underlying molecular mechanism remains largely unclear. Using yeast two-hybrid screening, bimolecular fluorescence complementation, and co-immunoprecipitation, we identified a TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family transcription factor, GhTCP7, that interacts with GhWIP2 both in vitro and in vivo. Using reverse genetic approaches, we elucidated the function of the GhTCP7-GhWIP2 complex in controlling petal expansion. GhTCP7 overexpression severely reduced cell expansion and petal size, whereas GhTCP7 silencing resulted in increased cell expansion and petal size. GhTCP7 showed similar expression patterns to GhWIP2 in various types of G. hybrida petals. We further identified GhIAA26 , which encodes an auxin signalling regulator, that is activated by the GhTCP7-GhWIP2 complex, leading to the suppression of petal expansion. Our findings reveal a previously unknown transcriptional regulatory mechanism that involves protein-protein interactions between two different transcription factor families to activate a negative regulator of petal organogenesis. [ABSTRACT FROM AUTHOR]

TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors contain specific a basic helix–loop–helix structure, which is a significant factor in the regulation of plant growth and development. TCP has been studied in several species, but no pineapple TCP has been reported to date. Whether they are involved in the development of the flower and fruit in the pineapple remains unclear. In this study, nine non-redundant pineapple TCPs (AcTCPs) were identified. Chromosomal localization, phylogenetics, gene structure, motifs, multiple-sequence alignment, and covariance on AcTCP family members were analyzed. Analysis of promoter cis-acting elements illustrated that the AcTCP gene may be mainly co-regulated by light signal and multiple hormone signals. Analysis of expression characteristics showed a significant increase in AcTCP5 expression at 12 h after ethylene treatment, and significantly higher levels of AcTCP8 and AcTCP9 expression in the pistil than in other floral organs. Meanwhile, the AcTCP4, AcTCP5, AcTCP6, AcTCP7, and AcTCP9 expression levels were downregulated at later stages of fruit development. Transcription factors that may interact with TCP protein in the regulation of flower and fruit development are screened by the protein interaction prediction network, AcTCP5 interacts with AcSPL16, and AcTCP8 interacts with AcFT5 and AcFT6 proteins, verified by Y2H experiments. These findings provide a basis for further exploration of the molecular mechanisms and function of the AcTCP gene in flower and fruit development. [ABSTRACT FROM AUTHOR]

Plant structure has a large influence on crop yield formation, with branching and plant height being the important factors that make it up. We identified a gene, MtTCP18, encoding a TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor highly conserved with Arabidopsis gene BRC1 (BRANCHED1) in Medicago truncatula. Sequence analysis revealed that MtTCP18 included a conserved basic helix–loop–helix (BHLH) motif and R domain. Expression analysis showed that MtTCP18 was expressed in all organs examined, with relatively higher expression in pods and axillary buds. Subcellular localization analysis showed that MtTCP18 was localized in the nucleus and exhibited transcriptional activation activity. These results supported its role as a transcription factor. Meanwhile, we identified a homozygous mutant line (NF14875) with a mutation caused by Tnt1 insertion into MtTCP18. Mutant analysis showed that the mutation of MtTCP18 altered plant structure, with increased plant height and branch number. Moreover, we found that the expression of auxin early response genes was modulated in the mutant. Therefore, MtTCP18 may be a promising candidate gene for breeders to optimize plant structure for crop improvement.

Teosinte branched/Cycloidea/Proliferating cell factors (TCPs), a small transcription gene family, serve in developmental processes such as branching, flowering, and growth of plants. In this study, the TCP transcription gene family of eucalyptus, which is considered important for its medicinal and industrial uses, was bioinformatically investigated. A total of 16 Eucalyptus grandis TCP (Egra-TCP) genes were found to be distributed on chromosomes 1, 2, 4, 6, 7, 9, 10 and 11. Several segmentally-duplicated gene couples including Egra-TCP-7/Egra-TCP-11, -13 and -16, Egra-TCP-6/Egra-TCP-12 and -15, Egra-TCP-12/Egra-TCP-15 and Egra-TCP-11/Egra-TCP-13 were discovered. Egra-TCPs were divided into three main clades based on phylogenetic analysis, motif, and gene structure. While Egra-TCP-10 has the highest molecular weight with 47.19 kDa, the lowest was Egra-TCP-1 with 21.68 kDa. Twelve Egra-TCP genes were found to have no introns, while the Egra-TCP-7, -15, and -16 genes had a single intron. The orthologous relationships among E. grandis/Arabidopsis thaliana and E. grandis/Vitis vinifera were identified through a synteny analysis. Digital gene expression profiles of Egra-TCP genes in tissues such as xylem, phloem, shoot tips, young and mature leaf revealed a high expression pattern. The findings of this study contributes to existing knowledge in the biotechnology field by providing contributing to our understanding of the molecular basis of the TCP gene family in the eucalyptus plant. [ABSTRACT FROM AUTHOR]

TCP transcription factors play a key role in regulating various developmental processes, particularly in shoot branching, flower development, and leaf development, and these factors are exclusively found in plants. However, comprehensive studies investigating TCP transcription factors in pepper (Capsicum annuum L.) are lacking. In this study, we identified 27 CaTCP members in the pepper genome, which were classified into Class I and Class II through phylogenetic analysis. The motif analysis revealed that CaTCPs in the same class exhibit similar numbers and distributions of motifs. We predicted that 37 previously reported miRNAs target 19 CaTCPs. The expression levels of CaTCPs varied in various tissues and growth stages. Specifically, CaTCP16, a member of Class II (CIN), exhibited significantly high expression in flowers. Class I CaTCPs exhibited high expression levels in leaves, while Class II CaTCPs showed high expression in lateral branches, especially in the CYC/TB1 subclass. The expression profile suggests that CaTCPs play specific roles in the developmental processes of pepper. We provide a theoretical basis that will assist in further functional validation of the CaTCPs.

Summary: The understanding of neo‐functionalization of plant transcription factors (TFs) after gene duplication has been extensively focused on changes in protein–protein interactions, the expression pattern of TFs, or the variation of cis‐elements bound by TFs. Yet, the main molecular role of a TF, that is, its specific chromatin binding for the direct regulation of target gene expression, continues to be mostly overlooked.Here, we studied the TB1 clade of the TEOSINTE BRANCHED 1, CYCLOIDEA, PROLIFERATING CELL FACTORS (TCP) TF family within the grasses (Poaceae).We identified an Asp/Gly amino acid replacement within the TCP domain, originated within a paralog TIG1 clade exclusive for grasses. The heterologous expression of Zea mays TB1 and its two paralogs BAD1 and TIG1 in Arabidopsis mutant plants lacking the TB1 ortholog BRC1 revealed distinct functions in plant development. Notably, the Gly acquired in the TIG1 clade does not impair TF homodimerization and heterodimerization, while it modulates chromatin binding preferences. We found that in vivo TF recognition of target promoters depends on this Asp/Gly mutation and directly impacts downstream gene expression and subsequent plant development.These results provided new insights into how natural selection fine‐tunes gene expression regulation after duplication of TFs to define plant architecture. [ABSTRACT FROM AUTHOR]

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Peppermint (Mentha x piperita) is a species with inhibitory allelopathic properties due to its high amounts of terpenes. Recent studies have disclosed dosage dependent growth promotion or defense reactions in plants when facing appropriate amounts of Mentha bouquet terpenes. These positive effects could be of interest for agricultural applications. To obtain more insights into leaf growth modulations, the expression of Arabidopsis and Brassica rapa TCP transcription factors were studied after fumigation with M. x piperita bouquets (Arabidopsis), with M. x piperita essential oil or with limonene (Arabidopsis and Chinese cabbage). According to qPCR studies, expression of TCP3, TCP24, and TCP20 were downregulated by all treatments in Arabidopsis, leading to altered leaf growth. Expressions of B. rapa TCPs after fumigation with the essential oil or limonene were less affected. Extensive greenhouse and polytunnel trials with white cabbage and Mentha plants showed that the developmental stage of the leaves, the dosage, and the fumigation time are of crucial importance for changed fresh and dry weights. Although further research is needed, the study may contribute to a more intensive utilization of ecologically friendly and species diversity conservation and positive allelopathic interactions in future agricultural systems. [ABSTRACT FROM AUTHOR]

The TEOSINTE BRANCHED1 (TBI1), CYCLOIDEA (CYC), and PROLIFERATING CELL NUCLEAR ANTIGEN FACTORS (PCF1 and PCF2) proteins truncated as TCP transcription factors carry conserved basic-helix-loop-helix (bHLH) structure, related to DNA binding functions. Evolutionary history of the TCP genes has shown their presence in early land plants. In this paper, we performed a comparative discussion on the current knowledge of the TCP Transcription Factors in lower and higher plants: their evolutionary history based on the phylogenetics of 849 TCP proteins from 37 plant species, duplication events, and biochemical roles in some of the plants species. Phylogenetics investigations confirmed the classification of TCP TFs into Class I (the PCF1/ 2), and Class II (the C- clade) factors; the Class II factors were further divided into the CIN- and CYC/TB1- subclade. A trace in the evolution of the TCP Factors revealed an absence of the CYC/TB1subclade in lower plants, and an independent evolution of the CYC/TB1subclade in both eudicot and monocot species. 54% of the total duplication events analyzed were biased towards the dispersed duplication, and we concluded that dispersed duplication events contributed to the expansion of the TCP gene family. Analysis in the TCP factors functional roles confirmed their involvement in various biochemical processes which mainly included promoting cell proliferation in leaves in Class I TCPs, and cell division during plant development in Class II TCP Factors. Apart from growth and development, the TCP Factors were also shown to regulate hormonal and stress response pathways. Although this paper does not exhaust the present knowledge of the TCP Transcription Factors, it provides a base for further exploration of the gene family. [ABSTRACT FROM AUTHOR]

TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors contain specific a basic helix–loop–helix structure, which is a significant factor in the regulation of plant growth and development. TCP has been studied in several species, but no pineapple TCP has been reported to date. Whether they are involved in the development of the flower and fruit in the pineapple remains unclear. In this study, nine non-redundant pineapple TCPs (AcTCPs) were identified. Chromosomal localization, phylogenetics, gene structure, motifs, multiple-sequence alignment, and covariance on AcTCP family members were analyzed. Analysis of promoter cis-acting elements illustrated that the AcTCP gene may be mainly co-regulated by light signal and multiple hormone signals. Analysis of expression characteristics showed a significant increase in AcTCP5 expression at 12 h after ethylene treatment, and significantly higher levels of AcTCP8 and AcTCP9 expression in the pistil than in other floral organs. Meanwhile, the AcTCP4, AcTCP5, AcTCP6, AcTCP7, and AcTCP9 expression levels were downregulated at later stages of fruit development. Transcription factors that may interact with TCP protein in the regulation of flower and fruit development are screened by the protein interaction prediction network, AcTCP5 interacts with AcSPL16, and AcTCP8 interacts with AcFT5 and AcFT6 proteins, verified by Y2H experiments. These findings provide a basis for further exploration of the molecular mechanisms and function of the AcTCP gene in flower and fruit development.

Main conclusion: Bioinformatic analysis of moso bamboo TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTORS (TCP) transcription factors reveals their conservation and variation as well as the probable biological functions in abiotic stress response. Overexpressing PheTCP9 in Arabidopsis thaliana illustrates it may exhibit a new vision in different aspects of response to salt stress. Plant specific TCPs play important roles in plant growth, development and stress response, but studies of TCP in moso bamboo are limited. Therefore, in this study, a total of 40 TCP genes (PheTCP1 ~ 40) were identified and characterized from moso bamboo genome and divided into three different subfamilies, namely, 7 in TEOSINTE BRANCHED 1 / CYCLOIDEA (TB1/CYC), 14 in CINCINNATA (CIN) and 19 in PROLIFERATING CELL FACTOR (PCF). Subsequently, we analyzed the gene structures and conserved domain of these genes and found that the members from the same subfamilies exhibited similar exon/intron distribution patterns. Selection pressure and gene duplication analysis results indicated that PheTCP genes underwent strong purification selection during evolution. There were many cis-elements related to phytohermone and stress responsive existing in the upstream promoter regions of PheTCP genes, such as ABRE, CGTCA-motif and ARE. Subcellular localization experiments showed that PheTCP9 was a nuclear localized protein. As shown by β-glucuronidase (GUS) activity, the promoter of PheTCP9 was significantly indicated by salt stress. PheTCP9 was significantly induced in the roots, stems and leaves of moso bamboo. It was also significantly induced by NaCl solution. Overexpressing PheTCP9 increased the salt tolerance of transgenic Arabidopsis. Meanwhile, H2O2 and malondialdehyde (MDA) contents were significantly lower in PheTCP9 over expression (OE) transgenic Arabidopsis than WT. Catalase (CAT) activity, K+/Na+ ratio as well as CAT2 expression level was also much improved in transgenic Arabidopsis than WT under salt conditions. In addition, PheTCP9 OE transgenic Arabidopsis held higher survival rates of seedlings than WT under NaCl conditions. These results showed the positive regulation functions of PheTCP9 in plants under salt conditions. [ABSTRACT FROM AUTHOR]

MicroRNA319 (miR319) has been implicated in leaf development in a number of plant species. Here we study the roles of miR319a and its regulated network in leaf development in poplars. Over-expression of miR319a in Populus alba × Populus glandulosa caused dwarf statures, narrow leaf blades and serrated leaf margins. The vascular bundles and bundle sheaths in transgenic leaves had more layers of cells than those in the leaves of control plants, indicating enhanced lignification in these cells. Among the 93 putative targets of miR319a predicted with the psRNATarget tool, only three genes, TCP (TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATING CELL NUCLEAR ANTIGEN BINDING FACTOR), were differentially expressed in the leaves of MIR319a-over-expression transgenic lines. With the RNA-seq data sets from multiple MIR319a over-expression transgenic lines, we built a three-layered gene regulatory network mediated by miR319a using Top-down graphic Gaussian model (GGM) algorithm that is capable of capturing causal relationships from transcriptomic data. The results support that miR319a primarily regulates the lignin biosynthesis, leaf development and differentiation as well as photosynthesis via miR319-MEE35/TCP4, miR319-TCP2 and miR319-TCP2-1 regulatory modules.

Teosinte branched 1/cycloidea/proliferating cell factor (TCP) transcription factors play a key role in the regulation of plant biotic and abiotic stresses. In this study, our results show that SmTCP7a positively regulated bacterial wilt that was caused by Ralstonia solanacearum. ChIP-seq was conducted to analyze the transcriptional regulation mechanism of SmTCP7a before (R0 h) and 48 h after infection (R48 h). SmTCP7a regulated a total of 92 and 91 peak-associated genes in R0 h and R48 h, respectively. A KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis showed that phenylpropanoid biosynthesis, MAPK (mitogen-activated protein kinas) signaling pathway, plant hormone signal transduction and plant-pathogen interactions were involved. The difference in peaks between R0 h and R48 h showed that there were three peak-associated genes that were modulated by infection. A better understanding of the potential target genes of SmTCP7a in response to R. solanacearum will provide a comprehensive understanding of the SmTCP7a regulatory mechanism during the eggplant defense response to bacterial wilt. [ABSTRACT FROM AUTHOR]

Autopolyploids often exhibit plant characteristics different from their diploid ancestors and are frequently associated with altered genes expression controlling growth and development. TCP is a unique transcription factor family in plants that is closely related to plant growth and development. Based on transcriptome sequencing of Chrysanthemum nankingense , 23 full-length TCP genes were cloned. The expression of CnTCP9 was most variable in tetraploids, at least threefold greater than diploids. Due to the lack of a C. nankingense transgenic system, we overexpressed CnTCP9 in Arabidopsis thaliana (Col-0) and Chrysanthemum morifolium. Overexpression of CnTCP9 caused enlargement of leaves in A. thaliana and petals in C. morifolium , and the expression of genes downstream of the GA pathway in C. morifolium were increased. Our results suggest that autopolyploidization of C. nankingense led to differential expression of TCP family genes, thereby affecting plant characteristics by the GA pathway. This study improves the understanding of enlarged plant size after autopolyploidization. [ABSTRACT FROM AUTHOR]

Ma bamboo (Dendrocalamus latiflorus Munro) is the most widely cultivated clumping bamboo in Southern China and is valuable for both consumption and wood production. The development of bamboo shoots involving the occurrence of lateral buds is unique, and it affects both shoot yield and the resulting timber. Plant-specific TCP transcription factors are involved in plant growth and development, particularly in lateral bud outgrowth and morphogenesis. However, the comprehensive information of the TCP genes in Ma bamboo remains poorly understood. In this study, 66 TCP transcription factors were identified in Ma bamboo at the genome-wide level. Members of the same subfamily had conservative gene structures and conserved motifs. The collinear analysis demonstrated that segmental duplication occurred widely in the TCP transcription factors of Ma bamboo, which mainly led to the expansion of a gene family. Cis-acting elements related to growth and development and stress response were found in the promoter regions of DlTCPs. Expression patterns revealed that DlTCPs have tissue expression specificity, which is usually highly expressed in shoots and leaves. Subcellular localization and transcriptional self-activation experiments demonstrated that the five candidate TCP proteins were typical self-activating nuclear-localized transcription factors. Additionally, the transcriptome analysis of the bamboo shoot buds at different developmental stages helped to clarify the underlying functions of the TCP members during the growth of bamboo shoots. DlTCP12-C , significantly downregulated as the bamboo shoots developed, was selected to further verify its molecular function in Arabidopsis. The DlTCP12-C overexpressing lines exhibited a marked reduction in the number of rosettes and branches compared with the wild type in Arabidopsis , suggesting that DlTCP12-C conservatively inhibits lateral bud outgrowth and branching in plants. This study provides useful insights into the evolutionary patterns and molecular functions of the TCP transcription factors in Ma bamboo and provides a valuable reference for further research on the regulatory mechanism of bamboo shoot development and lateral bud growth. [ABSTRACT FROM AUTHOR]

Plant-specific TCP transcription factors play a key role in plant development and stress responses. Chrysanthemum nankingense shows higher cold tolerance than its ornamental polyploid counterpart. However, whether the TCP gene family plays a role in conferring cold tolerance upon C. nankingense remains unknown. Here, we identified 23 CnTCP genes in C. nankingense, systematically analyzed their phylogenetic relationships and synteny with TCPs from other species, and evaluated their expression profiles at low temperature. Phylogenetic analysis of the protein sequences suggested that CnTCP proteins fall into two classes and three clades, with a typical bHLH domain. However, differences between C. nankingense and Arabidopsis in predicted protein structure and binding sites suggested a unique function of CnTCPs in C. nankingense. Furthermore, expression profiles showed that expression of most CnTCPs were downregulated under cold conditions, suggesting their importance in plant responses to cold stress. Notably, expression of miR319 and of its predicted target genes, CnTCP2/4/14, led to fast responses to cold. Overexpression of Arabidopsis CnTCP4 led to hypersensitivity to cold, suggesting that CnTCP4 might play a negative role in C. nankingense responses to cold stress. Our results provide a foundation for future functional genomic studies on this gene family in chrysanthemum. [ABSTRACT FROM AUTHOR]

Autopolyploids often exhibit plant characteristics different from their diploid ancestors and are frequently associated with altered genes expression controlling growth and development. TCP is a unique transcription factor family in plants that is closely related to plant growth and development. Based on transcriptome sequencing of Chrysanthemum nankingense, 23 full-length TCP genes were cloned. The expression of CnTCP9 was most variable in tetraploids, at least threefold greater than diploids. Due to the lack of a C. nankingense transgenic system, we overexpressed CnTCP9 in Arabidopsis thaliana (Col-0) and Chrysanthemum morifolium. Overexpression of CnTCP9 caused enlargement of leaves in A. thaliana and petals in C. morifolium, and the expression of genes downstream of the GA pathway in C. morifolium were increased. Our results suggest that autopolyploidization of C. nankingense led to differential expression of TCP family genes, thereby affecting plant characteristics by the GA pathway. This study improves the understanding of enlarged plant size after autopolyploidization.

Ma bamboo (Dendrocalamus latiflorus Munro) is the most widely cultivated clumping bamboo in Southern China and is valuable for both consumption and wood production. The development of bamboo shoots involving the occurrence of lateral buds is unique, and it affects both shoot yield and the resulting timber. Plant-specific TCP transcription factors are involved in plant growth and development, particularly in lateral bud outgrowth and morphogenesis. However, the comprehensive information of the TCP genes in Ma bamboo remains poorly understood. In this study, 66 TCP transcription factors were identified in Ma bamboo at the genome-wide level. Members of the same subfamily had conservative gene structures and conserved motifs. The collinear analysis demonstrated that segmental duplication occurred widely in the TCP transcription factors of Ma bamboo, which mainly led to the expansion of a gene family. Cis-acting elements related to growth and development and stress response were found in the promoter regions of DlTCPs. Expression patterns revealed that DlTCPs have tissue expression specificity, which is usually highly expressed in shoots and leaves. Subcellular localization and transcriptional self-activation experiments demonstrated that the five candidate TCP proteins were typical self-activating nuclear-localized transcription factors. Additionally, the transcriptome analysis of the bamboo shoot buds at different developmental stages helped to clarify the underlying functions of the TCP members during the growth of bamboo shoots. DlTCP12-C, significantly downregulated as the bamboo shoots developed, was selected to further verify its molecular function in Arabidopsis. The DlTCP12-C overexpressing lines exhibited a marked reduction in the number of rosettes and branches compared with the wild type in Arabidopsis, suggesting that DlTCP12-C conservatively inhibits lateral bud outgrowth and branching in plants. This study provides useful insights into the evolutionary patterns and molecular functions of the TCP transcription factors in Ma bamboo and provides a valuable reference for further research on the regulatory mechanism of bamboo shoot development and lateral bud growth.

Key message: Proper root growth depends on the clearance of TCP transcripts from the root apical meristem by microRNA miR319. The evolutionarily conserved microRNA miR319 regulates genes encoding TCP transcription factors in angiosperms. The miR319-TCP module controls cell proliferation and differentiation in leaves and other aerial organs. The current model sustains that miR319 quantitatively tunes TCP activity during leaf growth and development, ultimately affecting its size. In this work we studied how this module participates in Arabidopsis root development. We found that misregulation of TCP activity through impairment of miR319 binding decreased root meristem size and root length. Cellular and molecular analyses revealed that high TCP activity affects cell number and cyclin expression but not mature cell length, indicating that, in roots, unchecking the expression of miR319-regulated TCPs significantly affects cell proliferation. Conversely, tcp multiple mutants showed no obvious effect on root growth, but strong defects in leaf morphogenesis. Therefore, in contrast to the quantitative regulation of the TCPs by miR319 in leaves, our data suggest that miR319 clears TCP transcripts from root cells. Hence, we provide new insights into the functions of the miR319-TCP regulatory system in Arabidopsis development, highlighting a different modus operandi for its action mechanism in roots and shoots. [ABSTRACT FROM AUTHOR]

Ophiorrhiza pumila (O. pumila; Op) is a medicinal herbaceous plant, which can accumulate camptothecin (CPT). CPT and its derivatives are widely used as chemotherapeutic drugs for treating malignant tumors. Its biosynthesis pathway has been attracted significant attention. Teosinte branched 1/cycloidea/proliferating cell factors 1/2 (TCP) transcription factors (TFs) regulate a variety of physiological processes, while TCP TFs are involved in the regulation of CPT biosynthesis remain unclear. In this study, a systematic analysis of the TCP TFs family in O. pumila was performed. A total of 16 O. pumila TCP (OpTCP) genes were identified and categorized into two subgroups based on their phylogenetic relationships with those in Arabidopsis thaliana. Tissue-specific expression patterns revealed that nine OpTCP genes showed the highest expression levels in leaves, while the other seven OpTCPs showed a higher expression level in the stems. Co-expression, phylogeny analysis, and dual-luciferase (Dual-LUC) assay revealed that OpTCP15 potentially plays important role in CPT and its precursor biosynthesis. In addition, the subcellular localization experiment of candidate OpTCP genes showed that they are all localized in the nucleus. Our study lays a foundation for further functional characterization of the candidate OpTCP genes involved in CPT biosynthesis regulation and provides new strategies for increasing CPT production.

Ophiorrhiza pumila (O. pumila ; Op) is a medicinal herbaceous plant, which can accumulate camptothecin (CPT). CPT and its derivatives are widely used as chemotherapeutic drugs for treating malignant tumors. Its biosynthesis pathway has been attracted significant attention. Teosinte branched 1/cycloidea/proliferating cell factors 1/2 (TCP) transcription factors (TFs) regulate a variety of physiological processes, while TCP TFs are involved in the regulation of CPT biosynthesis remain unclear. In this study, a systematic analysis of the TCP TFs family in O. pumila was performed. A total of 16 O. pumila TCP (OpTCP) genes were identified and categorized into two subgroups based on their phylogenetic relationships with those in Arabidopsis thaliana. Tissue-specific expression patterns revealed that nine OpTCP genes showed the highest expression levels in leaves, while the other seven OpTCPs showed a higher expression level in the stems. Co-expression, phylogeny analysis, and dual-luciferase (Dual-LUC) assay revealed that OpTCP15 potentially plays important role in CPT and its precursor biosynthesis. In addition, the subcellular localization experiment of candidate OpTCP genes showed that they are all localized in the nucleus. Our study lays a foundation for further functional characterization of the candidate OpTCP genes involved in CPT biosynthesis regulation and provides new strategies for increasing CPT production. [ABSTRACT FROM AUTHOR]

Abstract Background The plant-specific TCP transcription factors play different functions in multiple processes of plant growth and development. TCP family genes have been identified in several plant species, but no comprehensive analysis of the TCP family in grapevine has been undertaken to date, especially their roles in fruit development. Results A total of 18 non-redundant grapevine TCP (VvTCP) genes distributing on 11 chromosomes were identified. Phylogenetic and structural analysis showed that VvTCP genes were divided into two main classes - class I and class II. The Class II genes were further classified into two subclasses, the CIN subclass and the CYC/TB1 subclass. Segmental duplication was a predominant duplication event which caused the expansion of VvTCP genes. The cis-acting elements analysis and tissue-specific expression patterns of VvTCP genes demonstrated that these VvTCP genes might play important roles in plant growth and development. Expression patterns of VvTCP genes during fruit development and ripening were analyzed by RNA-Seq and qRT-PCR. Among them, 11 VvTCP genes were down-regulated during different fruit developmental stages, while only one VvTCP genes were up-regulated, suggesting that most VvTCP genes were probably related to early development in grapevine fruit. Futhermore, the expression of most VvTCP genes can be inhibited by drought and waterlogging stresses. Conclusions Our study establishes the first genome-wide analysis of the grapevine TCP gene family and provides valuable information for understanding the classification and functions of the TCP genes in grapevine.

Peppermint (Mentha x piperita) is a species with inhibitory allelopathic properties due to its high amounts of terpenes. Recent studies have disclosed dosage dependent growth promotion or defense reactions in plants when facing appropriate amounts of Mentha bouquet terpenes. These positive effects could be of interest for agricultural applications. To obtain more insights into leaf growth modulations, the expression of Arabidopsis and Brassica rapa TCP transcription factors were studied after fumigation with M. x piperita bouquets (Arabidopsis), with M. x piperita essential oil or with limonene (Arabidopsis and Chinese cabbage). According to qPCR studies, expression of TCP3, TCP24, and TCP20 were downregulated by all treatments in Arabidopsis, leading to altered leaf growth. Expressions of B. rapa TCPs after fumigation with the essential oil or limonene were less affected. Extensive greenhouse and polytunnel trials with white cabbage and Mentha plants showed that the developmental stage of the leaves, the dosage, and the fumigation time are of crucial importance for changed fresh and dry weights. Although further research is needed, the study may contribute to a more intensive utilization of ecologically friendly and species diversity conservation and positive allelopathic interactions in future agricultural systems.

Plant-specific TCP transcription factors play vital roles in the controlling of growth, development, and the stress response processes. Extensive researches have been carried out in numerous species, however, there hasn’t been any information available about TCP genes in sweet potato (Ipomoea batatas L.). In this study, a genome-wide analysis of TCP genes was carried out to explore the evolution and function in sweet potato. Altogether, 18 IbTCPs were identified and cloned. The expression profiles of the IbTCPs differed dramatically in different organs or different stages of leaf development. Furthermore, four CIN-clade IbTCP genes contained miR319-binding sites. Blocking IbmiR319 significantly increased the expression level of IbTCP11/17 and resulted in a decreased photosynthetic rate due to the change in leaf submicroscopic structure, indicating the significance of IbmiR319-targeted IbTCPs in leaf anatomical morphology. A systematic analyzation on the characterization of the IbTCPs together with the primary functions in leaf anatomical morphology were conducted to afford a basis for further study of the IbmiR319/IbTCP module in association with leaf anatomical morphology in sweet potato.

Plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PROLIFERATING CELL FACTORS (TCP) transcription factors have versatile functions in plant growth, development and response to environmental stress. Despite blueberry’s value as an important fruit crop, the TCP gene family has not been systematically studied in this plant. The current study identified blueberry TCP genes (VcTCPs) using genomic data from the tetraploid blueberry variety ‘Draper’; a total of 62 genes were obtained. Using multiple sequence alignment, conserved motif, and gene structure analyses, family members were divided into two subfamilies, of which class II was further divided into two subclasses, CIN and TB1. Synteny analysis showed that genome-wide or segment-based replication played an important role in the expansion of the blueberry TCP gene family. The expression patterns of VcTCP genes during fruit development, flower bud dormancy release, hormone treatment, and tissue-specific expression were analyzed using RNA-seq and qRT-PCR. The results showed that the TB1 subclass members exhibited a certain level of expression in the shoot, leaf, and bud; these genes were not expressed during fruit development, but transcript levels decreased uniformly during the release of flower bud dormancy by low-temperature accumulation. The further transgenic experiments showed the overexpression of VcTCP18 in Arabidopsis significantly decreased the seed germination rate in contrast to the wild type. The bud dormancy phenomena as late-flowering, fewer rosettes and main branches were also observed in transgenic plants. Overall, this study provides the first insight into the evolution, expression, and function of VcTCP genes, including the discovery that VcTCP18 negatively regulated bud dormancy release in blueberry. The results will deepen our understanding of the function of TCPs in plant growth and development.

Plant-specific TCP transcription factors play vital roles in the controlling of growth, development, and the stress response processes. Extensive researches have been carried out in numerous species, however, there hasn't been any information available about TCP genes in sweet potato (Ipomoea batatas L.). In this study, a genome-wide analysis of TCP genes was carried out to explore the evolution and function in sweet potato. Altogether, 18 IbTCPs were identified and cloned. The expression profiles of the IbTCPs differed dramatically in different organs or different stages of leaf development. Furthermore, four CIN-clade IbTCP genes contained miR319-binding sites. Blocking IbmiR319 significantly increased the expression level of IbTCP11/17 and resulted in a decreased photosynthetic rate due to the change in leaf submicroscopic structure, indicating the significance of IbmiR319-targeted IbTCPs in leaf anatomical morphology. A systematic analyzation on the characterization of the IbTCPs together with the primary functions in leaf anatomical morphology were conducted to afford a basis for further study of the IbmiR319 / IbTCP module in association with leaf anatomical morphology in sweet potato. [ABSTRACT FROM AUTHOR]

Pathogens produce effectors to overcome plant immunity, thereby threatening crop yields and global food security. Large-scale interactomic studies have revealed that pathogens from different kingdoms of life target common plant proteins during infection, the so-called effector hubs. These hubs often play central roles in numerous plant processes through their ability to interact with multiple plant proteins. This ability arises partly from the presence of intrinsically disordered domains (IDDs) in their structure. Here, we highlight the role of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) and JASMONATE-ZIM DOMAIN (JAZ) transcription regulator families as plant signaling and effector hubs. We consider different evolutionary hypotheses to rationalize the existence of diverse effectors sharing common targets and the possible role of IDDs in this interaction. An increasing number of large-scale interactomic studies have revealed that pathogens from different kingdoms of life target common plant proteins during infection, the so-called effector hubs. Effector hubs are enriched in plant hubs, meaning they are highly connected and centralized in the plant protein–protein interaction network. Members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) and JASMONATE-ZIM DOMAIN (JAZ) transcription regulator families were identified as heavily targeted effector hubs. Effector hubs often possess intrinsically disordered domains (IDDs) to enable interaction with multiple partners. The possible role of IDDs in plant–pathogen interactions is still unclear. In silico network prediction and in-depth large-scale interactomic analyses, such as yeast two-hybrid (Y2H)-seq and turboID proximity labeling, are crucial in obtaining a global picture of conserved and specific plant–pathogen interplay. [ABSTRACT FROM AUTHOR]

Plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PROLIFERATING CELL FACTORS (TCP) transcription factors have versatile functions in plant growth, development and response to environmental stress. Despite blueberry's value as an important fruit crop, the TCP gene family has not been systematically studied in this plant. The current study identified blueberry TCP genes (VcTCPs) using genomic data from the tetraploid blueberry variety 'Draper'; a total of 62 genes were obtained. Using multiple sequence alignment, conserved motif, and gene structure analyses, family members were divided into two subfamilies, of which class II was further divided into two subclasses, CIN and TB1. Synteny analysis showed that genome-wide or segment-based replication played an important role in the expansion of the blueberry TCP gene family. The expression patterns of VcTCP genes during fruit development, flower bud dormancy release, hormone treatment, and tissue-specific expression were analyzed using RNA-seq and qRT-PCR. The results showed that the TB1 subclass members exhibited a certain level of expression in the shoot, leaf, and bud; these genes were not expressed during fruit development, but transcript levels decreased uniformly during the release of flower bud dormancy by low-temperature accumulation. The further transgenic experiments showed the overexpression of VcTCP18 in Arabidopsis significantly decreased the seed germination rate in contrast to the wild type. The bud dormancy phenomena as late-flowering, fewer rosettes and main branches were also observed in transgenic plants. Overall, this study provides the first insight into the evolution, expression, and function of VcTCP genes, including the discovery that VcTCP18 negatively regulated bud dormancy release in blueberry. The results will deepen our understanding of the function of TCPs in plant growth and development. [ABSTRACT FROM AUTHOR]

Background Teosinte branched1/Cycloidea/proliferating cell factors (TCPs) are plant-specific transcription factors widely involved in leaf development, flowering, shoot branching, the circadian rhythm, hormone signaling, and stress responses. However, the TCP function in Brassica juncea var. tumida, the tumorous stem mustard, has not yet been reported. This study identified and characterized the entire TCP family members in B. juncea var. tumida. Methods We identified 62 BjTCP genes from the B. juncea var. tumida genome and analyzed their phylogenetic relationship, gene structure, protein motifs, chromosome location, and expression profile in different tissues. Results Of the 62 BjTCP genes we identified in B. juncea var. tumida, containing 34 class I and 28 class II subfamily members, 61 were distributed on 18 chromosomes. Gene structure and conserved motif analysis showed that the same clade genes displayed a similar exon/intron gene structure and conserved motifs. Cis-acting element results showed that the same clade genes also had a similar cis-acting element; however, subtle differences implied a different regulatory pathway. The BjTCP18s members were low-expressed in Dayejie strains and the unswelling stage of Yonganxiaoye strains. Treatment with gibberellin (GA) and salicylic acid (SA) showed that GA and SA affect the expression levels of multiple TCP genes. Conclusion We performed the first genome-wide analysis of the TCP gene family of B. juncea var. tumida. Our results have provided valuable information for understanding the classification and functions of TCP genes in B. juncea var. tumida.

Trichomes and the cuticle are two specialized structures of the aerial epidermis that are important for plant organ development and interaction with the environment. In this study, we report that Arabidopsis thaliana plants affected in the function of the class I TEOSINTE BRANCHED 1, CYCLOIDEA, PCF (TCP) transcription factors TCP14 and TCP15 show overbranched trichomes in leaves and stems and increased cuticle permeability. We found that TCP15 regulates the expression of MYB106, a MIXTA-like transcription factor involved in epidermal cell and cuticle development, and overexpression of MYB106 in a tcp14 tcp15 mutant reduces trichome branch number. TCP14 and TCP15 are also required for the expression of the cuticle biosynthesis genes CYP86A4 , GPAT6 , and CUS2 , and of SHN1 and SHN2, two AP2/EREBP transcription factors required for cutin and wax biosynthesis. SHN1 and CUS2 are also targets of TCP15, indicating that class I TCPs influence cuticle formation acting at different levels, through the regulation of MIXTA-like and SHN transcription factors and of cuticle biosynthesis genes. Our study indicates that class I TCPs are coordinators of the regulatory network involved in trichome and cuticle development. [ABSTRACT FROM AUTHOR]

Plant-specific TCP transcription factors play a key role in plant development and stress responses. Chrysanthemum nankingense shows higher cold tolerance than its ornamental polyploid counterpart. However, whether the TCP gene family plays a role in conferring cold tolerance upon C. nankingense remains unknown. Here, we identified 23 CnTCP genes in C. nankingense, systematically analyzed their phylogenetic relationships and synteny with TCPs from other species, and evaluated their expression profiles at low temperature. Phylogenetic analysis of the protein sequences suggested that CnTCP proteins fall into two classes and three clades, with a typical bHLH domain. However, differences between C. nankingense and Arabidopsis in predicted protein structure and binding sites suggested a unique function of CnTCPs in C. nankingense. Furthermore, expression profiles showed that expression of most CnTCPs were downregulated under cold conditions, suggesting their importance in plant responses to cold stress. Notably, expression of miR319 and of its predicted target genes, CnTCP2/4/14, led to fast responses to cold. Overexpression of Arabidopsis CnTCP4 led to hypersensitivity to cold, suggesting that CnTCP4 might play a negative role in C. nankingense responses to cold stress. Our results provide a foundation for future functional genomic studies on this gene family in chrysanthemum.

SAP11 is an effector protein that has been identified in various phytoplasma species. It localizes in the plant nucleus and can bind and destabilize TEOSINE BRANCHES/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors. Although SAP11 of different phytoplasma species share similar activities, their protein sequences differ greatly. Here, we demonstrate that the SAP11-like protein of ‘Candidatus Phytoplasma mali’ (‘Ca. P. mali’) strain PM19 localizes into the plant nucleus without requiring the anticipated nuclear localization sequence (NLS). We show that the protein induces crinkled leaves and siliques, and witches’ broom symptoms, in transgenic Arabidopsis thaliana (A. thaliana) plants and binds to six members of class I and all members of class II TCP transcription factors of A. thaliana in yeast two-hybrid assays. We also identified a 17 amino acid stretch previously predicted to be a nuclear localization sequence that is important for the binding of some of the TCPs, which results in a crinkled leaf and silique phenotype in transgenic A. thaliana. Moreover, we provide evidence that the SAP11-like protein has a destabilizing effect on some TCPs in vivo.

Shoot branching is a key process for plant growth and fitness. Newly produced axes result from axillary bud outgrowth, which is at least partly mediated through the regulation of BRANCHED1 gene expression (BRC1/TB1/FC1). BRC1 encodes a pivotal bud-outgrowth-inhibiting transcription factor belonging to the TCP family. As the regulation of BRC1 expression is a hub for many shoot-branching-related mechanisms, it is influenced by endogenous (phytohormones and nutrients) and exogenous (light) inputs, which involve so-far only partly identified molecular networks. This review highlights the central role of BRC1 in shoot branching and its responsiveness to different stimuli, and emphasizes the different knowledge gaps that should be addressed in the near future.

TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTORS (T), members of a plant-specific gene family, play significant roles during plant growth and development, as well as in response to environmental stress. However, knowledge about this family in moso bamboo (Phyllostachys edulis) is limited. Therefore, in this study, the first genome-wide identification, classification, characterization, and expression pattern analysis of the TCP transcription factor family in moso bamboo was performed. Sixteen TCP members were identified from the moso bamboo genome using a BLASTP algorithm-based method and verified using the Pfam database. Based on a multiple-sequence alignment, the members were divided into two subfamilies, and members of the same family shared highly conserved motif structures. Subcellular localization and transactivation activity analyses of four selected genes revealed that they were nuclear localized and had self-activation activities. Additionally, the expression levels of several PeTCP members were significantly upregulated under abscisic acid, methyl jasmonate, and salicylic acid treatments, indicating that they play crucial plant hormone transduction roles in the processes of plant growth and development, as well as in responses to environmental stresses. Thus, the current study provides previously lacking information on the TCP family in moso bamboo and reveals the potential functions of this gene family in growth and development.