Characterization of TBP and TAFs in Mungbean (Vigna radiata L.) and Their Potential Involvement in Abiotic Stress Response

The TATA-box binding protein (TBP) and TBP-associated factors (TAFs) constitute the transcription factor IID (TFIID), a crucial component of RNA polymerase II, essential for transcription initiation and regulation. Several TFIID subunits are shared with the Spt–Ada–Gcn5–acetyltransferase (SAGA) coactivator complex. Recent research has revealed the roles of TBP and TAFs in organogenesis and stress adaptation. In this study, we identified 1 TBP and 21 putative TAFs in the mungbean genome, among which VrTAF5, VrTAF6, VrTAF8, VrTAF9, VrTAF14, and VrTAF15 have paralogous genes. Their potential involvement in abiotic stress responses was also investigated here, including high salinity, water deficit, heat, and cold. The findings indicated that distinct genes exerted predominant influences in the response to different abiotic stresses through potentially unique mechanisms. Specifically, under salt stress, VrTBP, VrTAF2, and VrTAF15–1 were strongly induced, while VrTAF10, VrTAF11, and VrTAF13 acted as negative regulators. In the case of water-deficit stress, it was likely that VrTAF1, VrTAF2, VrTAF5–2, VrTAF9, and VrTAF15–1 were primarily involved. Additionally, in response to changes in ambient temperature, it was possible that genes such as VrTAF5–1, VrTAF6–1, VrTAF9–2, VrTAF10, VrTAF13, VrTAF14b–2, and VrTAF15–1 might play a dominant role. This comprehensive exploration of VrTBP and VrTAFs can offer a new perspective on understanding plant stress responses and provide valuable insights into breeding improvement.


Introduction
In eukaryotes, three canonical DNA-dependent RNA polymerases (Pol I, II, and III) are responsible for transcribing ribosomal RNA genes, protein-coding (as well as several non-coding) genes, and small RNA genes, respectively [1,2].Despite this diversification, the TATA box binding protein (TBP) is regarded as the central component recruiting the different polymerases by assembling various sets of subunits [3,4].RNA Pol II has been extensively researched due to its pivotal role in transcribing protein-coding genes.During RNA Pol IIdirected transcription, TBP functions within a multi-subunit complex known as transcription factor IID (TFIID)-a general transcription factor that initiates transcription by nucleating pre-initiation complex (PIC) assembly at the core promoter [5][6][7].TFIID is a complex of over 1 megadalton (MDa), consisting of TBP and 13-14 evolutionarily conserved TBP-associated factors (TAFs) [8][9][10][11].The Spt-Ada-Gcn5-acetyltransferase (SAGA) coactivator has been shown to share subunits with TFIID and acts synergistically in chromatin modification and TBP loading [12,13].In higher eukaryotes, the SAGA complex comprises over 20 polypeptide subunits organized into four functional modules: the TAF module, SPT module, histone acetyltransferase (HAT) module, and histone deubiquitination (DUB) module [10,14,15].Biological development and adaption to the environment are intricately regulated at the genetic level, and the role of general transcription factors (GTFs) cannot be ignored [2,16].Research has demonstrated that the release of paused Pol II is a critical developmental checkpoint, either by accelerating the speed of gene activation or suppressing transcriptional noise [17].TFIID and SAGA make overlapping contributions to TBP binding on the core promoter during transcription regulation.While the presence of a TATA box is not essential for transcription, genes containing it in their promoter region are typically associated with responses to environmental stress and exhibit variable expression levels, which depend more strongly on SAGA-mediated TBP binding [12,18].In fact, only 5-10% of human core promoters and 20% of yeast genes contain a TATA box element [19,20].However, TFIID may have a more substantial impact on the regulation of constitutive genes, as its binding to promoters lacking a TATA box is governed by TAFs that recognize other essential promoter elements [1,12,19].TAFs have been shown to exhibit multifaceted activities in the regulation of transcription, encompassing the following roles: (1) facilitating extended promoter recognition; (2) functioning as coactivators that integrate activator-derived signals into the basal transcription machinery; (3) serving as a conduit to facilitate communication between TFIID and nucleosomes; (4) acting as a factor for activator-independent reinitiation; and (5) interacting with epigenetic modification-related components [5,21,22].
TBP and TAFs exhibit a high degree of conservation from yeast to humans, with their roles in regulating cell differentiation, cell cycle, organ development, and stress adaptation well studied in humans [21,22], fruit flies [23,24], and yeast [12,25,26].Recently, an increasing number of studies have highlighted the important functions of TBP and TAFs in controlling plant development and stress response, particularly in model plants, such as Arabidopsis.Two TBPs (TBP1 and TBP2) and 18 putative TAFs have been identified through the BLAST search in the Arabidopsis genome [7,27,28].Changes in the abundance of TBP in Arabidopsis can impact plant development throughout the entire growth stage, including shoot apical meristems, leaves, flower organs, fertility, pollen tube growth, and light response [7].AtTAF5 (At5g25150) has been demonstrated to be an indispensable gene for the complete life cycle of plants, playing a role in inflorescence meristems, male gametogenesis, and pollen tube growth [29].Additionally, AtTAF10 (At4g31720) is involved in plant osmotic stress adaptation, and the overexpression of AtTAF10 can enhance seed tolerance to salt stress during germination [30].It has been demonstrated that AtTAF10 is one of the selectively expressed TAFs, showing a preference for transient expression during plant development.AtTAF10 is enriched in vascular tissue, and the knockdown of AtTAF10 results in several abnormal phenotypes related to meristem activity and leaf development [31].Furthermore, It has been found that TAF12b (At1g17440) controls the Arabidopsis enhanced ethylene response 4 (eer4), cytokinin hypersensitive 1 (ckh1), and bz1728 suppressor mutants nobiro, indicating its pleiotropic function in ethylene response, cytokinin signal, and environment-responsive root growth control through an unfolded protein response (UPR) [32][33][34].AtTAF13 (At1g02680) collaborates with Polycomb Repressive Complex 2 (PRC2) during seed development, and the taf13 mutation results in embryo arrest and the over-proliferation of the endosperm [35].Additionally, both AtTAF14 (At2g18000) and TAF15b (At5g58470) are implicated in flowering regulation by interacting with FLOWERING LOCUS C (FLC).AtTAF14 interacts with the FRIGIDA complex, which activates FLC to repress flowering [36].Conversely, TAF15b directly represses FLC transcription to influence the flowering time, particularly through the autonomous pathway (AP) in Arabidopsis [37].Moreover, AtTAF15b has been demonstrated to regulate toll interleukin 1 receptor-type NLR (TNL)-mediated immunity through post-transcriptional RNA processing.Notably, the homologous gene of AtTAF15b, AtTAF15 (At1g50300) exhibits different topologies and a distinct function in Arabidopsis [38].The rice genome also contains two genes encoding TBP proteins: OsTBP1 and OsTBP2 [39].OsTBP2.1 can bind to the TATA-box of OsNRT2.3 and alter the ratio of OsNRT2.3b to OsNRT2.3a,leading to an increased rice yield by promoting nitrogen uptake [40].Conversely, knockdown lines of OsTBP2.2 showed heightened sensitivity to drought stress and growth retardation [41].Furthermore, OsTAF2 regulates grain size together with its interacting protein POW1 [42,43].In finger millet (Eleusine coracana L.), transcriptome analysis indicates that TBP and TAFs exhibit strong responses to drought stress [44].Additionally, VrTAF5 is identified as a potential gene for mungbean Cercospora leaf-spot disease resistance [45].Nonetheless, the specific roles of plant TBP and TAFs are still poorly understood, and further research is urgently needed.
Mungbean (Vigna radiata L.) is a significant grain legume crop with a high nutritional value and economic importance [46].Mungbean plays a crucial role in agricultural sustainability due to its favorable characteristics, such as wide adaptability, nitrogen fixation capacity, short life span, and high biomass production [47,48].This study systematically identifies mungbeans VrTBP and VrTAFs, including their encoded genes, structures, conserved domains, and phylogenetic trees.Furthermore, their potential roles in abiotic stress response to high salinity, water deficit, heat, and cold are preliminarily interpreted.These findings offer a new perspective on plant stress response and can facilitate the application of crop improvement under stressful conditions.

Systematic Analysis of Mungbean TBP and Putative TAFs
We further investigate the reliability of the putative VrTBP and VrTAFs by analyzing the gene structure, protein domains, sequence identity to Arabidopsis homologous proteins, as well as the expression level and phylogenetic tree of TBPs and TAFs proteins from multispecies, respectively.The specific details are as follows.

VrTBP
Only one VrTBP protein, encoded by LOC106754936 (scaffold NW_014543812.1),has been isolated and characterized in mungbean genome (Table 1 and Figure 1).Despite its small size of 200 amino acids, the gene sequence of VrTBP consists of eight exons and seven introns (Figure 2A).VrTBP contains two 'Pfam TBP'-related domains located at positions ranging from 22-104 aa and 112-195 aa (Figure 2B), and exhibits a very high sequence identity of 92.5% and 93.5% with AtTBP1 and AtTBP2, respectively (Figure 2C and Table S1).Furthermore, VrTBP demonstrates significant expression levels in both leavf and root tissues (Figure 2D).TBP exhibits a relatively conservative evolutionary pattern (Figure 2E).Our data indicate that the TBPs from legume crops, such as Vigna angularis (Va), Glycine max (Gm), and Medicago truncatula (Mt), form a distinct cluster, with each of these crops appearing to contain only one TBP, as is the case with mungbean.In contrast, Arabidopsis thaliana (At), Oryza sativa (Os), and Zea mays (Zm) each have two distinct TBPs, but OsTBP1and OsTB2 are not grouped together (Figure 2E).

Systematic Analysis of Mungbean TBP and Putative TAFs
We further investigate the reliability of the putative VrTBP and VrTAFs by analyzing the gene structure, protein domains, sequence identity to Arabidopsis homologous proteins, as well as the expression level and phylogenetic tree of TBPs and TAFs proteins from multi-species, respectively.The specific details are as follows.

VrTBP
Only one VrTBP protein, encoded by LOC106754936 (scaffold NW_014543812.1),has been isolated and characterized in mungbean genome (Table 1 and Figure 1).Despite its small size of 200 amino acids, the gene sequence of VrTBP consists of eight exons and seven introns (Figure 2A).VrTBP contains two 'Pfam TBP'-related domains located at positions ranging from 22-104 aa and 112-195 aa (Figure 2B), and exhibits a very high sequence identity of 92.5% and 93.5% with AtTBP1 and AtTBP2, respectively (Figure 2C and Table S1).Furthermore, VrTBP demonstrates significant expression levels in both leavf and root tissues (Figure 2D).TBP exhibits a relatively conservative evolutionary pattern (Figure 2E).Our data indicate that the TBPs from legume crops, such as Vigna angularis (Va), Glycine max (Gm), and Medicago truncatula (Mt), form a distinct cluster, with each of these crops appearing to contain only one TBP, as is the case with mungbean.In contrast, Arabidopsis thaliana (At), Oryza sativa (Os), and Zea mays (Zm) each have two distinct TBPs, but OsTBP1and OsTB2 are not grouped together (Figure 2E).

VrTAF1
LOC106777544 encodes the VrTAF1 protein in mungbean, which is located on chr11 (Vradi11g07970.1)and has four transcripts, including X1: XM_014665146.2,X2: XM_014665147.2,X3: XM_014665148.2,and X4: XM_022776030.1 (Table 1 and Figure 1).VrTAF1 is the largest subunit in TFIID with a length of up to 1901 amino acids.VrTAF1-X1 consists of 21 exons, with alternative splicing mainly occurring on the first five exons, resulting in three additional transcripts (Figure 3A).The absence of a sequence in VrTAF1-X2/X3/X4 leads to the omission of the 'Pfam TBP-binding' domain.Other feature domains, such as UBQ for ubiquitination, ZnF_C2HC, and the BROMO domain for interaction with acetylated lysine are present (Figure 3B).The sequence identity of these four VrTAF1 proteins to AtTAF1 (1919 aa) ranges from 54.9% to 55.8% (Figure 3C and Table S1), with all showing detectable transcriptional levels.Among them, VrTAF1-X1 and VrTAF1-X4 exhibit significantly higher expressions (Figure 3D).Phylogenetic analysis reveals that TAF1 proteins from legume crops form a distinct group, with VaTAF1 being the closest relative (Figure 3E).Additionally, TAF1 proteins from monocotyledon and dicotyledon species show clear evolutionary separation.Eventually, VrTAF1-X1 was chosen for further investigation.
LOC106777544 encodes the VrTAF1 protein in mungbean, which is located on chr11 (Vradi11g07970.1)and has four transcripts, including X1: XM_014665146.2,X2: XM_014665147.2,X3: XM_014665148.2,and X4: XM_022776030.1 (Table 1 and Figure 1).VrTAF1 is the largest subunit in TFIID with a length of up to 1901 amino acids.VrTAF1-X1 consists of 21 exons, with alternative splicing mainly occurring on the first five exons, resulting in three additional transcripts (Figure 3A).The absence of a sequence in VrTAF1-X2/X3/X4 leads to the omission of the 'Pfam TBP-binding' domain.Other feature domains, such as UBQ for ubiquitination, ZnF_C2HC, and the BROMO domain for interaction with acetylated lysine are present (Figure 3B).The sequence identity of these four VrTAF1 proteins to AtTAF1 (1919 aa) ranges from 54.9% to 55.8% (Figure 3C and Table S1), with all showing detectable transcriptional levels.Among them, VrTAF1-X1 and VrTAF1-X4 exhibit significantly higher expressions (Figure 3D).Phylogenetic analysis reveals that TAF1 proteins from legume crops form a distinct group, with VaTAF1 being the closest relative (Figure 3E).Additionally, TAF1 proteins from monocotyledon and dicotyledon species show clear evolutionary separation.Eventually, VrTAF1-X1 was chosen for further investigation.2), and TAF1-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.2), and TAF1-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.
VrTAF2 is the second largest subunit of TFIID, encoded by LOC106768217 on chr07 (Vradi07g18120.1),and consists of three alternative splicing transcripts (Table 1 and Figure 1).VrTAF2-X1 (XM_014653218.2) contains 25 exons, while VrTAF2-X2 (XM_022783661.1)lacks the 20th exon, and VrTAF2-X3 (XM_022783662.1) is missing the last two exons (Figure 4A).Protein domain analysis reveals that, compared with VrTAF2-X1, VrTAF2-X2 has a relatively shorter 'scop d1gw5a' domain, and VrTAF2-X3 lacks the 'low complexity and coiled coil regions' on the C-terminal, but retains all four important domains (Figure 4B).Three transcripts all exhibit over 60% identity to AtTAF2 (1390 aa) (Figure 4C and Table S1), however only VrTAF2-X1 demonstrates a high level of transcript abundance in both the roots and leaves of mungbean (Figure 4D).Therefore, VrTAF2-X1 represents a valuable transcript for further investigation.Similar to TAF1 in evolution, legume TAF2 proteins are closely clustered together, and VrTAF2 is closest to VaTAF2 (Figure 4E).2), and TAF2-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

VrTAF4b
Up to seven transcripts of VrTAF4b are available in the NCBI database (Table 1).Sequence analysis reveals that VrTAF4b-X1, X2, X3, and X4 share identical sequences, as do VrTAF4b-X6 and X7 (Figure 5A,C).Among these, VrTAF4b-X2, X5, and X7 are selected for domain analysis due to their relatively higher expression levels (Figure 5D).It is observed that the VrTAF4b-X5 protein lacks a sequence of four amino acids (570-573  2), and TAF2-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

VrTAF4b
Up to seven transcripts of VrTAF4b are available in the NCBI database (Table 1).Sequence analysis reveals that VrTAF4b-X1, X2, X3, and X4 share identical sequences, as do VrTAF4b-X6 and X7 (Figure 5A,C).Among these, VrTAF4b-X2, X5, and X7 are selected for domain analysis due to their relatively higher expression levels (Figure 5D).It is observed that the VrTAF4b-X5 protein lacks a sequence of four amino acids (570-573 LSSQ), which does not appear to affect the main domains, such as RST and TAF4 domains.Pfam RST (for RCD1, SRO, and TAF4) domain is a plant-specific domain-mediated protein-protein interaction.On the other hand, VrTAF4b-X7 is shorter due to missing the first two exons and part of the third exon, resulting in a loss of 'low complexity' on the N-terminal region (Figure 5B).The sequence identity with AtTAF4b (852 aa) is approximately 51.3% (Figure 5C and Table S1).The evolutionary trend of TAF4b shows a similarity to TAF1 and TAF2; however, there is no equivalent TAF4b in yeast (Figure 5E).In conclusion, further study may focus on investigating VrTAF4b-X2 (XM_014648978.2) as a candidate protein due to its highest transcript level.
LSSQ), which does not appear to affect the main domains, such as RST and TAF4 domains.Pfam RST (for RCD1, SRO, and TAF4) domain is a plant-specific domain-mediated protein-protein interaction.On the other hand, VrTAF4b-X7 is shorter due to missing the first two exons and part of the third exon, resulting in a loss of 'low complexity' on the N-terminal region (Figure 5B).The sequence identity with AtTAF4b (852 aa) is approximately 51.3% (Figure 5C and Table S1).The evolutionary trend of TAF4b shows a similarity to TAF1 and TAF2; however, there is no equivalent TAF4b in yeast (Figure 5E).In conclusion, further study may focus on investigating VrTAF4b-X2 (XM_014648978.2) as a candidate protein due to its highest transcript level.
Int. J. Mol.Sci.2024, 25, x FOR PEER REVIEW 12 of 31 conserved domains found in TAF6, such as 'TAF' and 'TAF6_C', which are present in both VrTAF6-1 and VrTAF6-2 (Figure 7B).Additionally, the expression of VrTAF6-like cannot be detected at the transcriptional level (Figure 7D), suggesting it may be a pseudogene.Furthermore, VrTAF6-1 and VrTAF6-2 exhibit sequence identities of 65.9% and 56.1%, respectively, to AtTAF6 (549 aa) (Figure 7C and Table S1).In the evolution, VrTAF6-1 is more similar to VaTAF6, while VrTAF6-2 appears to be closer to the TAF6 proteins in monocotyledon (Figure 7E).Based on the results, VrTAF6-1 and VrTAF6-2 are being examined further in relation to stress response.

VrTAF7
Located on chr06 (Vradi06g12480.1),LOC106763916 is annotated as possessing the TAF7 function, a small protein consisting of only 199 amino acids (Table 1 and Figure 1).Despite the presence of two transcripts, XM_014648094.2(1) and XM_022782426.1 (2), in the NCBI database, they exhibit identical sequences at both the transcriptional and protein levels.However, the transcription of XM_022782426.1 cannot be detected by RNA-seq (Figure 8D).Therefore, XM_014648094.2 is deemed to be the authentic tran-

VrTAF7
Located on chr06 (Vradi06g12480.1),LOC106763916 is annotated as possessing the TAF7 function, a small protein consisting of only 199 amino acids (Table 1 and Figure 1).Despite the presence of two transcripts, XM_014648094.2(1) and XM_022782426.1 (2), in the NCBI database, they exhibit identical sequences at both the transcriptional and protein levels.However, the transcription of XM_022782426.1 cannot be detected by RNA-seq (Figure 8D).Therefore, XM_014648094.2 is deemed to be the authentic transcript for VrTAF7 and will be utilized for further exploration.VrTAF7 comprises four exons and three introns, with its encoded protein containing a conserved 'TAFII55_N' domain at the N-terminus, characteristic of TAF7 proteins (Figure 8A,B).The protein sequence of VrTAF7 shares a significant identity of 69.5% with AtTAF7 (Figure 8C and Table S1), and its phylogenetic pattern closely resembles that of most TAFs (Figure 8E).script for VrTAF7 and will be utilized for further exploration.VrTAF7 comprises four exons and three introns, with its encoded protein containing a conserved 'TAFII55_N' domain at the N-terminus, characteristic of TAF7 proteins (Figure 8A and 8B).The protein sequence of VrTAF7 shares a significant identity of 69.5% with AtTAF7 (Figure 8C and Table S1), and its phylogenetic pattern closely resembles that of most TAFs (Figure 8E).Phylogenetic tree of TAF7 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

VrTAF8
Three loci distributed on different chromosomes, specifically LOC106759260 (Vra-di04g09290.1),LOC106764373 (Vradi06g06010.1),and LOC106769930 (Vradi08g07170.1),are described as TAF8-related proteins, encoding VrTAF8-1, VrTAF8-2, and VrTAF8like, respectively (Table 1 and Figure 1).VrTAF8-1 consists of two exons, while both VrTAF8-2 and VrTAF8-like have only one exon.Additionally, there is a significant difference in the length of the encoded proteins (Table 1 and Figure 9A).Notably, VrTAF8-2 is the shortest protein with a length of 290 amino acids and lacks the conserved motif 'TAF8_C' at the C-terminal end (Figure 9B).Furthermore, the sequence identity of VrTAF8-2 to AtTAF is only 26.0%, whereas that of VrTAF8-1 and VrTAF8like is 36.4% and 46.8%, respectively (Figure 9C and Table S1).The transcripts of all three genes can be detected by RNA-seq analysis (Figure 9D).On the phylogenetic tree, it can be observed that VrTAF8-1 clusters with TAF8 proteins from legume crops, while VrTAF8-like is grouped with AtTAF8.In contrast, VrTAF8-2 appears to be distantly related to TAF8 within the plant kingdom (Figure 9E).Hence, LOC106764373 may be a spurious VrTAF8, and further investigations will be conducted on VrTAF8-1 and VrTAF8-like.(E) Phylogenetic tree of TAF7 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

VrTAF10
The locus on chr04 (Vradi04g11480.1)LOC106758746 encodes the VrTAF10 protein in the mungbean genome.Two transcripts, XM_014641724.2(1) and XM_014641723.2(2), are listed on NCBI with identical sequences at both the mRNA and protein levels (Table 1 and Figure 1).Despite consisting of six exons, VrTAF10 encodes the smallest subunit of TFIID (136 aa, same as VrTAF13) (Figure 11A and Table 1).The 'Pfam TFIID_30kDa' domain is present in the VrTAF10 protein, which is also a component of other transcription regulatory multiprotein complexes, such as SAGA, TFTC, STAGA, and PCAF/GCN5 (Figure 11B).VrTAF10 shares a high sequence identity with AtTAF10 (82.1%) (Figure 11C and Table S1).The RNA-seq data show the detection of both VrTAF10(1) and VrTAF10(2), with the latter exhibiting approximately double the expression level of the former (Figure 11D).Notably, VrTAF10 can be grouped with TAF10 proteins from legumes, particularly closer to monocotyledon rather than Arabidopsis (Figure 11E).Consequently, further analysis under stresses will focus on the expression of VrTAF10(2).

VrTAF10
The locus on chr04 (Vradi04g11480.1)LOC106758746 encodes the VrTAF10 protein in the mungbean genome.Two transcripts, XM_014641724.2(1) and XM_014641723.2(2), are listed on NCBI with identical sequences at both the mRNA and protein levels (Table 1 and Figure 1).Despite consisting of six exons, VrTAF10 encodes the smallest subunit of TFIID (136 aa, same as VrTAF13) (Figure 11A and Table 1).The 'Pfam TFIID_30kDa' domain is present in the VrTAF10 protein, which is also a component of other transcription regulatory multiprotein complexes, such as SAGA, TFTC, STAGA, and PCAF/GCN5 (Figure 11B).VrTAF10 shares a high sequence identity with AtTAF10 (82.1%) (Figure 11C and Table S1).The RNA-seq data show the detection of both VrTAF10(1) and VrTAF10(2), with the latter exhibiting approximately double the expression level of the former (Figure 11D).Notably, VrTAF10 can be grouped with TAF10 proteins from legumes, particularly closer to monocotyledon rather than Arabidopsis (Figure 11E).Consequently, further analysis under stresses will focus on the expression of VrTAF10(2).

VrTAF11
The VrTAF11 gene is located on chr09 (Vradi09g05150.1)and consists of a single locus (LOC106773625) and transcript (XM_014660347.2) (Table 1 and Figure 1).It contains four exons, encoding a 204 amino acid protein, which is a relatively small subunit of TFIID (Figure 12A and Table 1).The C terminal of the VrTAF11 protein contains a conserved 'Pfam TAFII28' motif with four alpha helices and three loops arranged similarly to histone H3 (Figure 12B).The sequence identity between VrTAF11 and AtTAF11 is approximately 63.4% (Figure 12C and Table S1).A high expression of VrTAF11 can be detected in both leaves and roots (Figure 12D).In terms of evolution, VrTAF11 is most closely related to VaTAF11 among the TAF11 proteins (Figure 12E).2).The red circle indicates the protein from mungbean.

VrTAF11
The VrTAF11 gene is located on chr09 (Vradi09g05150.1)and consists of a single locus (LOC106773625) and transcript (XM_014660347.2) (Table 1 and Figure 1).It contains four exons, encoding a 204 amino acid protein, which is a relatively small subunit of TFIID (Figure 12A and Table 1).The C terminal of the VrTAF11 protein contains a conserved 'Pfam TAFII28' motif with four alpha helices and three loops arranged similarly to histone H3 (Figure 12B).The sequence identity between VrTAF11 and AtTAF11 is approximately 63.4% (Figure 12C and Table S1).A high expression of VrTAF11 can be detected in both leaves and roots (Figure 12D).In terms of evolution, VrTAF11 is most closely related to VaTAF11 among the TAF11 proteins (Figure 12E).
TFIID (Figure 12A and Table 1).The C terminal of the VrTAF11 protein contains a conserved 'Pfam TAFII28' motif with four alpha helices and three loops arranged similarly to histone H3 (Figure 12B).The sequence identity between VrTAF11 and AtTAF11 is approximately 63.4% (Figure 12C and Table S1).A high expression of VrTAF11 can be detected in both leaves and roots (Figure 12D).In terms of evolution, VrTAF11 is most closely related to VaTAF11 among the TAF11 proteins (Figure 12E). in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF11 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

VrTAF12b
A previous study on Arabidopsis demonstrated that TAF12 and TAF12b have differential affinities toward TFIID and SAGA components [49].Therefore, we did not include VrTAF12b in the analysis with VrTAF12, as these two protein sequences share only  2).The red circle indicates the protein from mungbean.

VrTAF12b
A previous study on Arabidopsis demonstrated that TAF12 and TAF12b have differential affinities toward TFIID and SAGA components [49].Therefore, we did not include VrTAF12b in the analysis with VrTAF12, as these two protein sequences share only 32.7% identity.LOC106774141, located on chr09 (Vradi09g02430.1),encodes VrTAF12b and has a single transcript, XM_014661010.2(Table 1 and Figure 1).In the genome, VrTAF12b consists of 13 exons and the coding protein is approximately twofold larger than that of VrTAF12 (Figure 14A).Apart from the C-terminal conserved domain, 'Pfam TFIID_20 kDa', there is a transmembrane helix region at the N-terminal (Figure 14B).VrTAF12b shares a 57.3% sequence identity with AtTAF12b, and its expression level is high in both the leaves and roots (Figure 14C, Table S1, and Figure 14D).In terms of evolution, no homologous protein of TAF12b has been identified in humans.The evolutionary model of VrTAF12b is similar to that of VrTAF12 as well as most other VrTAFs (Figure 14E).However, further research should be undertaken to explore the specific roles of VrTAF12b and VrTAF12.and has a single transcript, XM_014661010.2(Table 1 and Figure 1).In the genome, VrTAF12b consists of 13 exons and the coding protein is approximately twofold larger than that of VrTAF12 (Figure 14A).Apart from the C-terminal conserved domain, 'Pfam TFIID_20 kDa', there is a transmembrane helix region at the N-terminal (Figure 14B).VrTAF12b shares a 57.3% sequence identity with AtTAF12b, and its expression level is high in both the leaves and roots (Figure 14C, Table S1, and Figure 14D).In terms of evolution, no homologous protein of TAF12b has been identified in humans.The evolutionary model of VrTAF12b is similar to that of VrTAF12 as well as most other VrTAFs (Figure 14E).However, further research should be undertaken to explore the specific roles of VrTAF12b and VrTAF12.

VrTAF13
Only one locus, LOC106770840, on chr08 (Vradi08g10630.1)encodes the VrTAF13 protein, with up to six transcripts (Table 1 and Figure 1).Similar to the case of VrTAF12, these six transcripts of VrTAF13 are identical, containing five exons and producing a protein with 136 aa (Figure 15A and 15C).VrTAF13 is one of the smallest units in TFIID, featuring a conserved motif, 'Pfam TFIID_15KDa' (Figure 15B).Despite showing a high sequence identity of 70.4% to AtTAF13 (Figure 15C and Table S1), the evolutionary distance places it much closer to monocotyledon species (except legume), such as rice and maize, rather than AtTAF13 (Figure 15E).Among the six transcripts, VrTAF13 (1) exhib-  2).The red circle indicates the protein from mungbean.

VrTAF13
Only one locus, LOC106770840, on chr08 (Vradi08g10630.1)encodes the VrTAF13 protein, with up to six transcripts (Table 1 and Figure 1).Similar to the case of VrTAF12, these six transcripts of VrTAF13 are identical, containing five exons and producing a protein with 136 aa (Figure 15A,C).VrTAF13 is one of the smallest units in TFIID, featuring a conserved motif, 'Pfam TFIID_15KDa' (Figure 15B).Despite showing a high sequence identity of 70.4% to AtTAF13 (Figure 15C and Table S1), the evolutionary distance places it much closer to monocotyledon species (except legume), such as rice and maize, rather than AtTAF13 (Figure 15E).Among the six transcripts, VrTAF13 (1) exhibits the highest expression level in both the leaves and roots (Figure 15D), thus making it suitable for further analysis.

VrTAF15
LOC106777580 and LOC106760812 are identified as VrTAF15 coding genes, located on chr02 (Vradi02g02560.1)and chr05 (Vradi05g09940.1),respectively, designated as VrTAF15-1 and VrTAF15-2 (Table 1 and Figure 1).However, all analyses indicate that VrTAF15-2 appears to be a pseudogene.It consists of only two exons and encodes a protein with a length of 156 aa, while the protein encoded by VrTAF15-1 is 390 aa long with seven exons (Table 1 and Figure 17A).Protein domain analysis reveals that VrTAF15-2 contains three 'ZnF_RBZ 'motifs but lacks the N-terminal' RRM domains involved in RNA recognition (Figure 17B).The sequence identity of VrTAF15-1 to At-TAF15 is high at 73.1%, whereas that of VrTAF15-2 is only at 33.3% (Figure 17C and Table S1).The relative expression level of VrTAF15-2 is significantly lower compared to that of VrTAF15-1 (Figure 17D).Furthermore, VrTAF15-2 does not exhibit clustering with other plant TAF15 proteins on the phylogenetic tree, in contrast to VrTAF15-1, which is grouped with TAF15 from legume crops (Figure 17E).As a result, the further investigation of VrTAF15-2 is not warranted.

VrTAF15
LOC106777580 and LOC106760812 are identified as VrTAF15 coding genes, located on chr02 (Vradi02g02560.1)and chr05 (Vradi05g09940.1),respectively, designated as VrTAF15-1 and VrTAF15-2 (Table 1 and Figure 1).However, all analyses indicate that VrTAF15-2 appears to be a pseudogene.It consists of only two exons and encodes a protein with a length of 156 aa, while the protein encoded by VrTAF15-1 is 390 aa long with seven exons (Table 1 and Figure 17A).Protein domain analysis reveals that VrTAF15-2 contains three 'ZnF_RBZ 'motifs but lacks the N-terminal' RRM domains involved in RNA recognition (Figure 17B).The sequence identity of VrTAF15-1 to AtTAF15 is high at 73.1%, whereas that of VrTAF15-2 is only at 33.3% (Figure 17C and Table S1).The relative expression level of VrTAF15-2 is significantly lower compared to that of VrTAF15-1 (Figure 17D).Furthermore, VrTAF15-2 does not exhibit clustering with other plant TAF15 proteins on the phylogenetic tree, in contrast to VrTAF15-1, which is grouped with TAF15 from legume crops (Figure 17E).As a result, the further investigation of VrTAF15-2 is not warranted.

VrTAF15b
Two loci, LOC106752587 and LOC106752498, annotated as VrTAF15b (Table 1 and Figure 1), namely VrTAF15b-1 and VrTAF15b-2, respectively, both consisted of six exons.However, the length of the VrTAF15b-2 protein is significantly longer than that of VrTAF15b-1, with lengths of 524 aa and 422 aa, respectively (Table 1 and Figure 18A).Despite this difference in length, both variants share similar conserved protein motifs, including the N-terminal 'ZnF_RBZ' motif and C-terminal 'RRM' domain (Figure 18B).Furthermore, they exhibit a high sequence identity to AtTAF15b at approximately 63.6% and 66.9% for VrTAF15b-1 and VrTAF15b-2, respectively (Figure 18C and Table S1).The expression levels of both VrTAF15b variants are approximately equivalent (Figure 18D).Phylogenetic analysis reveals that VrTAf15b-1 is closely related to VaTAF15b, while VrTAF15b-2 is grouped with MtTAF15b- Relative expression levels of VrTAF15-1 and VrTAF15-2 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF15 from multi-species (see Figure 2).The red circles indicate the proteins from mungbean.

VrTAF15b
Two loci, LOC106752587 and LOC106752498, annotated as VrTAF15b (Table 1 and Figure 1), namely VrTAF15b-1 and VrTAF15b-2, respectively, both consisted of six exons.However, the length of the VrTAF15b-2 protein is significantly longer than that of VrTAF15b-1, with lengths of 524 aa and 422 aa, respectively (Table 1 and Figure 18A).Despite this difference in length, both variants share similar conserved protein motifs, including the N-terminal 'ZnF_RBZ' motif and C-terminal 'RRM' domain (Figure 18B).Furthermore, they exhibit a high sequence identity to AtTAF15b at approximately 63.6% and 66.9% for VrTAF15b-1 and VrTAF15b-2, respectively (Figure 18C and Table S1).The expression levels of both VrTAF15b variants are approximately equivalent (Figure 18D).Phylogenetic analysis reveals that VrTAf15b-1 is closely related to VaTAF15b, while VrTAF15b-2 is grouped with MtTAF15b-2.Interestingly, predictions for their subcellular locations suggest distinct distributions for the two variants (Table 1), indicating potential diverse roles in transcriptional regulation.

VrTBP and VrTAFs Expression in Response to Abiotic Stress Treatments
Based on the aforementioned analysis, 1 VrTBP and 21 VrTAFs were further investigated for their potential involvement in responding to abiotic stress.Four genes, including VrTAF6-like, VrTAF8-2, VrTAF9-1, and VrTAF15-2, have been identified as pseudogenes due to the absence of certain domains or undetectable expression.For the analysis of stress response, 12-day-old mungbean seedlings were subjected to treat- ulated at the latter time point.This suggests that these genes may play a dominant role in responding to salt stress in leaves.Conversely, in the roots, VrTAF12, VrTAF12b, and VrTAF15b-2 were significantly upregulated at both time points, while VrTAF5-2 and VrTAF6-1 were strongly reduced at 24 h.

Heat and Cold Stress
Mungbean seedlings were subjected to 35 • C and 4 • C for 24 h to investigate the impact of temperature on the expression of VrTBP and VrTAFs.Subsequently, gene expression levels in leaves were analyzed.The results depicted in Figures 21 and S3 reveal that VrTBP is significantly induced under cold conditions.Furthermore, several genes, including VrTAF5-1, VrTAF6-1, VrTAF9-2, VrTAF10, VrTAF13, VrTAF14b-2, and VrTAF15-1, exhibited an upregulation in response to heat stress, but a downregulation under cold stress.Notably, only the high temperature appeared to influence the expression of VrTAF2 and VrTAF5-2, while both heat and cold led to the downregulation of VrTAF6-2 and VrTAF11.These diverse response patterns indicate distinct regulatory mechanisms for these genes in adapting to environmental fluctuations.

Heat and Cold Stress
Mungbean seedlings were subjected to 35°C and 4°C for 24 h to investigate the impact of temperature on the expression of VrTBP and VrTAFs.Subsequently, gene expression levels in leaves were analyzed.The results depicted in Figures 21 and S3 reveal that VrTBP is significantly induced under cold conditions.Furthermore, several genes, including VrTAF5-1, VrTAF6-1, VrTAF9-2, VrTAF10, VrTAF13, VrTAF14b-2, and VrTAF15-1, exhibited an upregulation in response to heat stress, but a downregulation under cold stress.Notably, only the high temperature appeared to influence the expression of VrTAF2 and VrTAF5-2, while both heat and cold led to the downregulation of VrTAF6-2 and VrTAF11.These diverse response patterns indicate distinct regulatory mechanisms for these genes in adapting to environmental fluctuations.

Discussion
TBPs and TAFs are central components of the general transcription factor TFIID, with highly conserved sequences from yeast to humans [50].Therefore, utilizing bioinformatics tools, such as BLAST and Gcorn, to identify potential homologous proteins is

Discussion
TBPs and TAFs are central components of the general transcription factor TFIID, with highly conserved sequences from yeast to humans [50].Therefore, utilizing bioinformatics tools, such as BLAST and Gcorn, to identify potential homologous proteins is reliable.In our initial screening of the mungbean genome (Table 1), we identified 1 TBP and 25 putative TAFs.Previous research has demonstrated that mammals possess three members in the TBP family, namely TBP, TBP-like protein1 (TBPL1), and TBP-like protein2 (TBPL2 or TBP2) [1,16].In contrast, Arabidopsis, rice, and maize each have two copies of the TBPs [28,41,51], while the mungbean genome appears to only contain one copy of the TBP.This pattern is also observed in other legume crops, such as Vigna angularis, Glycine max, and Medicago truncatula.This phenomenon may be attributed to gene loss during evolution, or potentially supplemented by additional protein molecules to intricately and precisely regulate transcription.As for the VrTAF sequences, they exhibit some complexity: specifically, six types of TAFs (VrTAF5, VrTAF6, VrTAF8, VrTAF9, VrTAF14, and VrTAF15) have two to three encoding genes; five TAFs (VrTAF1, VrTAF2, VrTA4b, VrTAF5-1, and VrTAF9-1) have multiple transcripts; and four TAFs (VrTAF7, VrTAF10, VrTAF12, and VrTAF13) appear to have multiple transcripts, but with identical protein sequences.Then, we perform further biological analyses on all possible sequences, including gene structure, conserved domains, sequence identity to Arabidopsis homologous proteins and phylogenetic trees, as well as their expression level in the leaves and roots.The results indicate that VrTAF6-like, VrTAF8-2, VrTAF9-1, and VrTAF15-2 are likely to be pseudogenes, while the remaining 21 TAFs were analyzed under abiotic stress.Generally, the typical number of TAF subunits comprising TFIID is 13-14 [13,52].In Arabidopsis, 18 putative AtTAF proteins were identified [27].It is noteworthy that there is no homologous TAF3 in the mungbean genome, and TAF3 is also absent from the genomes of Arabidopsis and rice [27].Therefore, it is presumed that TAF3 is lacking in plants, but other TAF subunits may compensate for its function.Moreover, TAF4 and TAF14 homologous proteins also cannot be identified in the mungbean genome, but one VrTAF4b with multiple transcripts and two copies of VrTAF14b are isolated.Nevertheless, further biochemical and genetic studies are necessary to verify the real function of the TAF proteins in forming the TFIID complex and regulating transcription.
The mungbean genome contains up to six TAFs with two or three copies, potentially enhancing its plasticity to adapt to the complexity of transcriptional regulation during development and stress.In Arabidopsis, there are seven TAFs with two copies, namely AtTAF1, AtTAF4, AtTAF6, AtTAF11, AtTAF12, AtTAF14, and AtTAF15 [27].Further studies indicated that these different copies might function during diverse processes.Two Arabidopsis TAF1-related genes are known as TAF1 (At1g32750) and TAF1b (At3g19040), both of which possess histone acetyltransferase activity [27].A null mutation in taf1 is lethal, while taf1b lines are viable and fertile.Further investigations revealed that AtTAF1 is essential for resistance to genotoxic stress and pollen tube development through its interaction with MRE11, a core component involved in DNA double-strand break detection and repair [53].Meanwhile, AtTAF1b functions as a coactivator capable of integrating light signals and activating light-regulated genes through histone acetylation [54,55].Two paralogs of AtTAF4, TAF4 (At5g43130) and TAF4b (At1g27720), exhibit distinct expression patterns: TAF4 shows a broader constitutive expression, while TAF4b is enriched during meiosis and controls meiotic crossover events and germline transcription [56].Two AtTAF6related proteins (TAF6 encoded by At1g04950 and TAF6b encoded by At1g54360) also have been identified with non-redundant functions in Arabidopsis.Specifically, AtTAF6 regulates pollen tube growth, and loss-of-function mutants result in a lethal phenotype [57].The occurrence of gene duplication events is frequently attributed to the replication of genes during the process of evolution.Whether the multiple copies of VrTAFs have redundant or distinct functions during developmental process or stress response needs further investigation.
The pivotal regulatory role of TBPs and TAFs in plant development and stress response has garnered the attention of researchers.However, current studies predominantly focus on model plants (such as Arabidopsis and rice) [7,39], with limited reports available for other crops.In terms of abiotic stress response, previous studies have demonstrated the involvement of yeast ScTBP in hyperosmotic stress [26], and highlighted the important role of rice OsTBP2.2 during drought stress [41].In the protozoan parasite Entamoeba histolytica, the expression level of EhTAF1 was upregulated under heat shock stress [58].Additionally, TAF6 identified from finger millet (Eleusine coracana (L.) Gaertn), a droughtadapted crop, played a crucial role in safeguarding the transcription process under drought stress [59].In Arabidopsis, AtTAF10 has been demonstrated to be involved in the adaptation of plants to osmotic stress [30].Strikingly, TAF5, TAF6, TAF9, TAF10, and TAF12 subunits are also important components of the SAGA complex [13,60].Studies have shown that SAGA complexes in yeast, humans, and plants are involved in the regulation of stressresponsive gene transcription [12,15,61].Interestingly, in yeast, genes regulated by SAGA are predominantly induced by stress and do not rely on TAF subunits [12].SAGA is capable of facilitating TBP binding to the TATA-box and initiating transcription, as well as modulating gene expression in a manner dependent on other modules, such as the HAT module with the acetylation function and the DUB module with ubiquitination activity [15,18,62].
In this study, 1 TBP and 21 putative TAFs are systematically identified from the mungbean genome, including their gene structure, conserved domains, expression level, and phylogenetic tree analysis.Furthermore, the expressions of VrTBP and VrTAFs responding to stress (salt, water deficit, heat, and cold) were investigated, displaying diverse patterns.Specifically, VrTBP, VrTAF2, and VrTAF15-1 were identified as positive regulators of salt stress, while VrTAF10, VrTAF11, and VrTAF13 acted as negative regulators, primarily in the leaves.In the case of water-deficit stress, it is suggested that VrTAF1, VrTAF2, VrTAF5-2, VrTAF9, and VrTAF15-1 may play a predominant role.Regarding the changes in ambient temperature response, VrTAF5-1, VrTAF6-1, VrTAF9-2, VrTAF10, VrTAF13, VrTAF14b-2, and VrTAF15-1 may be key players.Thus, basal regulators like TBPs and TAFs are potential candidates linked to stress adaptation in plants.
All the sequence data can be found in the 'Supplementary Data'.

Plant Materials
Mungbean cultivar 'Sulyu 1' was selected as the tested material.The seedlings were grown in an illumination incubator at 28 • C/26 • C with a 16 h light/8 h dark photoperiod.The seedlings were cultivated in a 1:1 mixture of peat soil (0-20 mm, PINDSTRUP SUB-STRATE, Pindstrup, Denmark) and vermiculite.The 12-day-old healthy seedlings were selected for further treatment after germination.

High-Salinity Treatment
To simulate high-salinity stress, 12-day-old mungbean seedlings were soaked in liquid MS medium with 200 mM of NaCl for 6 h and 24 h.The seedlings treated with liquid MS medium served as the control.Then, we sampled the treated roots and leaves separately after flushing with ddH 2 O (3 times) and immediately froze them in liquid nitrogen.Treatment was repeated three times.

Water-Deficit Treatment
For water-deficit stress, 12-day-old mungbean seedlings were soaked in liquid MS medium with 15% (w/v) PEG6000 (polyethylene glycol) for 6 h and 24 h.The seedlings treated with liquid MS medium served as the control.Then, we sampled the treated roots and leaves separately after flushing with ddH 2 O (3 times) and immediately froze them in liquid nitrogen.Treatment was repeated three times.

Heat and Cold Treatment
For heat and cold treatments, 12-day-old mungbean seedlings were placed in the incubator at 4 • C (cold stress) and 35 • C (heat stress) for 24 h, respectively.The seedlings grown under 25 • C served as the control.The treated leaves were sampled and immediately frozen in liquid nitrogen.Treatment was repeated three times.

RNA-Seq, Data Statistical Analysis, and Visualization
Total RNA was extracted using a polysaccharide polyphenol plant total RNA extraction kit (PD Biotech, Shanghai, China), and then we conducted RNA-seq using the DNBSEQ platform (BGI, Shenzhen, China).Each sample produced an average of 6.34 Gb of data.We performed an analysis of differential gene enrichment within and between groups, and Venn maps were drawn.Then, the expression level of the genes of interest were picked out and statistically analyzed using Excel (Office 2017) and GraphPad Prism 5 software (https://www.graphpad.com/features)(accessed on 17 January 2024).TBtools [65] was used to draw heat maps after the FPKM value 698 taken logarithm (LOG 2).

Conclusions
GTFs were demonstrated to play a crucial role in plant development and adaptation to the environment.In this study, we systematically identified 1 TBP and 21 putative TAFs in the mungbean genome.These factors are essential components of the TFIID complex and

Figure 1 .
Figure 1.Distribution of VrTBP and VrTAFs from the mungbean genome.

Figure 1 .
Figure 1.Distribution of VrTBP and VrTAFs from the mungbean genome.

Figure 3 .
Figure 3. Multi-analysis of VrTAF1.(A) Gene structure of four transcripts of VrTAF1.(B) Domains of four VrTAF1 alternative splicing proteins by SMART.(C) Sequence identity to AtTAF1.(D) Relative expression level of VrTAF1s in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF1 from multi-species (see Figure 2), and TAF1-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 3 .
Figure 3. Multi-analysis of VrTAF1.(A) Gene structure of four transcripts of VrTAF1.(B) Domains of four VrTAF1 alternative splicing proteins by SMART.(C) Sequence identity to AtTAF1.(D) Relative expression level of VrTAF1s in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF1 from multi-species (see Figure 2), and TAF1-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 4 .
Figure 4. Multi-analysis of VrTAF2.(A) Gene structure of three transcripts of VrTAF2.(B) Domain analyzed of three VrTAF2 alternative splicing proteins by SMART.(C) Sequence identity to At-TAF2.(D) Relative expression level of VrTAF2 in the leaves and roots of mungbean seedlings.N.D.: Not detected.(E) Phylogenetic tree of TAF2 from multi-species (see Figure 2), and TAF2-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 4 .
Figure 4. Multi-analysis of VrTAF2.(A) Gene structure of three transcripts of VrTAF2.(B) Domain analyzed of three VrTAF2 alternative splicing proteins by SMART.(C) Sequence identity to AtTAF2.(D) Relative expression level of VrTAF2 in the leaves and roots of mungbean seedlings.N.D.: Not detected.(E) Phylogenetic tree of TAF2 from multi-species (see Figure 2), and TAF2-X1 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 5 .
Figure 5. Multi-analysis of VrTAF4b.(A) Gene structure of seven transcripts of VrTAF4b.(B) Domains analyzed of VrTAF4b-X2, VrTAF4b-X5, and VrTAF4b-X7 by SMART.(C) Sequence identity to AtTAF4b.(D) Relative expression level in the leaves and roots of mungbean seedlings.N.D.: Not detected.(E) Phylogenetic tree of TAF4b from multi-species (see Figure 2), and VrTAF4b-X2 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 5 .
Figure 5. Multi-analysis of VrTAF4b.(A) Gene structure of seven transcripts of VrTAF4b.(B) Domains analyzed of VrTAF4b-X2, VrTAF4b-X5, and VrTAF4b-X7 by SMART.(C) Sequence identity to AtTAF4b.(D) Relative expression level in the leaves and roots of mungbean seedlings.N.D.: Not detected.(E) Phylogenetic tree of TAF4b from multi-species (see Figure 2), and VrTAF4b-X2 is used here to construct the phylogenetic tree.The red circle indicates the protein from mungbean.

Figure 11 .
Figure 11.Multi-analysis of VrTAF10.(A) Gene structure of VrTAF10.(B) Domain analyzed of VrTAF10 by SMART.(C) Sequence identity to AtTAF10.(D) Relative expression level of VrTAF10 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF10 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 11 .
Figure 11.Multi-analysis of VrTAF10.(A) Gene structure of VrTAF10.(B) Domain analyzed of VrTAF10 by SMART.(C) Sequence identity to AtTAF10.(D) Relative expression level of VrTAF10 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF10 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 12 . 31 Figure 12 .
Figure 12.Multi-analysis of VrTAF11.(A) Gene structure of VrTAF11.(B) Domain analyzed of VrTAF11 by SMART.(C) Sequence identity to AtTAF11.(D) Relative expression level of VrTAF11 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF11 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 13 .
Figure 13.Multi-analysis of VrTAF12.(A) Gene structure of VrTAF12.(B) Domain analyzed of VrTAF12 by SMART.(C) Sequence identity to AtTAF12.(D) Relative expression level of VrTAF12 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF12 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 13 .
Figure 13.Multi-analysis of VrTAF12.(A) Gene structure of VrTAF12.(B) Domain analyzed of VrTAF12 by SMART.(C) Sequence identity to AtTAF12.(D) Relative expression level of VrTAF12 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF12 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 14 .
Figure 14.Multi-analysis of VrTAF12b.(A) Gene structure of VrTAF12b.(B) Domain analyzed of VrTAF12b by SMART.(C) Sequence identity to AtTAF12b.(D) Relative expression level of VrTAF12b in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF12b from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 14 .
Figure 14.Multi-analysis of VrTAF12b.(A) Gene structure of VrTAF12b.(B) Domain analyzed of VrTAF12b by SMART.(C) Sequence identity to AtTAF12b.(D) Relative expression level of VrTAF12b in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF12b from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 15 .
Figure 15.Multi-analysis of VrTAF13.(A) Gene structure of VrTAF13 (B) Domain analyzed of VrTAF13 by SMART.(C) Sequence identity to AtTAF13.(D) Relative expression level of VrTAF13 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF13 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Figure 15 .
Figure 15.Multi-analysis of VrTAF13.(A) Gene structure of VrTAF13 (B) Domain analyzed of VrTAF13 by SMART.(C) Sequence identity to AtTAF13.(D) Relative expression level of VrTAF13 in the leaves and roots of mungbean seedlings.(E) Phylogenetic tree of TAF13 from multi-species (see Figure 2).The red circle indicates the protein from mungbean.

Table 1 .
TBP and TAF genes in the mungbean genome.