@article{dai_zhai_lin_wang_meng_li_mao_gao_ma_zhang_et al._2023, title={Cell-type-specific PtrWOX4a and PtrVCS2 form a regulatory nexus with a histone modification system for stem cambium development in Populus trichocarpa}, ISSN={["2055-0278"]}, DOI={10.1038/s41477-022-01315-7}, abstractNote={Stem vascular cambium cells in forest trees produce wood for materials and energy. WOX4 affects the proliferation of such cells in Populus. Here we show that PtrWOX4a is the most highly expressed stem vascular-cambium-specific (VCS) gene in P. trichocarpa, and its expression is controlled by the product of the second most highly expressed VCS gene, PtrVCS2, encoding a zinc finger protein. PtrVCS2 binds to the PtrWOX4a promoter as part of a PtrWOX13a-PtrVCS2-PtrGCN5-1-PtrADA2b-3 protein tetramer. PtrVCS2 prevented the interaction between PtrGCN5-1 and PtrADA2b-3, resulting in H3K9, H3K14 and H3K27 hypoacetylation at the PtrWOX4a promoter, which led to fewer cambium cell layers. These effects on cambium cell proliferation were consistent across more than 20 sets of transgenic lines overexpressing individual genes, gene-edited mutants and RNA interference lines in P. trichocarpa. We propose that the tetramer-PtrWOX4a system may coordinate genetic and epigenetic regulation to maintain normal vascular cambium development for wood formation.}, journal={NATURE PLANTS}, author={Dai, Xiufang and Zhai, Rui and Lin, Jiaojiao and Wang, Zhifeng and Meng, Dekai and Li, Meng and Mao, Yuli and Gao, Boyuan and Ma, Hongyan and Zhang, Baofeng and et al.}, year={2023}, month={Jan} }
 @article{yu_zhou_li_li_lin_wang_chiang_li_2022, title={p A PtrLBD39-mediated transcriptional network regulates tension wood formation in Populus trichocarpa}, volume={3}, ISSN={["2590-3462"]}, url={http://europepmc.org/abstract/med/35059630}, DOI={10.1016/j.xplc.2021.100250}, abstractNote={Tension wood (TW) is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses (e.g., bending). The genetic regulation that underlies this important mechanism remains poorly understood. Here, we used laser capture microdissection of stem xylem cells coupled with full transcriptome RNA-sequencing to analyze TW formation in Populus trichocarpa. After tree bending, PtrLBD39 was the most significantly induced transcription factor gene; it has a phylogenetically paired homolog, PtrLBD22. CRISPR-based knockout of PtrLBD39/22 severely inhibited TW formation, reducing cellulose and increasing lignin content. Transcriptomic analyses of CRISPR-based PtrLBD39/22 double mutants showed that these two genes regulate a set of TW-related genes. Chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify direct targets of PtrLBD39. We integrated transcriptomic analyses and ChIP-seq assays to construct a transcriptional regulatory network (TRN) mediated by PtrLBD39. In this TRN, PtrLBD39 directly regulates 26 novel TW-responsive transcription factor genes. Our work suggests that PtrLBD39 and PtrLBD22 specifically control TW formation by mediating a TW-specific TRN in Populus.}, number={1}, journal={PLANT COMMUNICATIONS}, author={Yu, Jing and Zhou, Chenguang and Li, Danning and Li, Shuang and Lin, Ying-Chung Jimmy and Wang, Jack P. and Chiang, Vincent L. and Li, Wei}, year={2022}, month={Jan} }
 @article{lin_sun_song_chen_shi_yang_liu_tunlaya-anukit_liu_loziuk_et al._2021, title={Enzyme Complexes of Ptr4CL and PtrHCT Modulate Co-enzyme A Ligation of Hydroxycinnamic Acids for Monolignol Biosynthesis in Populus trichocarpa}, volume={12}, ISSN={["1664-462X"]}, url={http://europepmc.org/abstract/med/34691108}, DOI={10.3389/fpls.2021.727932}, abstractNote={Co-enzyme A (CoA) ligation of hydroxycinnamic acids by 4-coumaric acid:CoA ligase (4CL) is a critical step in the biosynthesis of monolignols. Perturbation of 4CL activity significantly impacts the lignin content of diverse plant species. In Populus trichocarpa, two well-studied xylem-specific Ptr4CLs (Ptr4CL3 and Ptr4CL5) catalyze the CoA ligation of 4-coumaric acid to 4-coumaroyl-CoA and caffeic acid to caffeoyl-CoA. Subsequently, two 4-hydroxycinnamoyl-CoA:shikimic acid hydroxycinnamoyl transferases (PtrHCT1 and PtrHCT6) mediate the conversion of 4-coumaroyl-CoA to caffeoyl-CoA. Here, we show that the CoA ligation of 4-coumaric and caffeic acids is modulated by Ptr4CL/PtrHCT protein complexes. Downregulation of PtrHCTs reduced Ptr4CL activities in the stem-differentiating xylem (SDX) of transgenic P. trichocarpa. The Ptr4CL/PtrHCT interactions were then validated in vivo using biomolecular fluorescence complementation (BiFC) and protein pull-down assays in P. trichocarpa SDX extracts. Enzyme activity assays using recombinant proteins of Ptr4CL and PtrHCT showed elevated CoA ligation activity for Ptr4CL when supplemented with PtrHCT. Numerical analyses based on an evolutionary computation of the CoA ligation activity estimated the stoichiometry of the protein complex to consist of one Ptr4CL and two PtrHCTs, which was experimentally confirmed by chemical cross-linking using SDX plant protein extracts and recombinant proteins. Based on these results, we propose that Ptr4CL/PtrHCT complexes modulate the metabolic flux of CoA ligation for monolignol biosynthesis during wood formation in P. trichocarpa.}, journal={FRONTIERS IN PLANT SCIENCE}, author={Lin, Chien-Yuan and Sun, Yi and Song, Jina and Chen, Hsi-Chuan and Shi, Rui and Yang, Chenmin and Liu, Jie and Tunlaya-Anukit, Sermsawat and Liu, Baoguang and Loziuk, Philip L. and et al.}, year={2021}, month={Oct} }
 @article{liu_liu_yu_wang_sun_li_lin_chiang_li_wang_2021, title={Transcriptional reprogramming of xylem cell wall biosynthesis in tension wood}, volume={186}, ISSN={["1532-2548"]}, url={https://doi.org/10.1093/plphys/kiab038}, DOI={10.1093/plphys/kiab038}, abstractNote={Abstract Tension wood (TW) is a specialized xylem tissue developed under mechanical/tension stress in angiosperm trees. TW development involves transregulation of secondary cell wall genes, which leads to altered wood properties for stress adaptation. We induced TW in the stems of black cottonwood (Populus trichocarpa, Nisqually-1) and identified two significantly repressed transcription factor (TF) genes: class B3 heat-shock TF (HSFB3-1) and MYB092. Transcriptomic analysis and chromatin immunoprecipitation (ChIP) were used to identify direct TF–DNA interactions in P. trichocarpa xylem protoplasts overexpressing the TFs. This analysis established a transcriptional regulatory network in which PtrHSFB3-1 and PtrMYB092 directly activate 8 and 11 monolignol genes, respectively. The TF–DNA interactions were verified for their specificity and transactivator roles in 35 independent CRISPR-based biallelic mutants and overexpression transgenic lines of PtrHSFB3-1 and PtrMYB092 in P. trichocarpa. The gene-edited trees (mimicking the repressed PtrHSFB3-1 and PtrMYB092 under tension stress) have stem wood composition resembling that of TW during normal growth and under tension stress (i.e., low lignin and high cellulose), whereas the overexpressors showed an opposite effect (high lignin and low cellulose). Individual overexpression of the TFs impeded lignin reduction under tension stress and restored high levels of lignin biosynthesis in the TW. This study offers biological insights to further uncover how metabolism, growth, and stress adaptation are coordinately regulated in trees.}, number={1}, journal={PLANT PHYSIOLOGY}, publisher={Oxford University Press (OUP)}, author={Liu, Baoguang and Liu, Juan and Yu, Jing and Wang, Zhifeng and Sun, Yi and Li, Shuang and Lin, Ying-Chung Jimmy and Chiang, Vincent L. and Li, Wei and Wang, Jack P.}, year={2021}, month={May}, pages={250–269} }
 @article{yeh_wang_miao_ma_kao_hsu_yu_hung_lin_kuan_et al._2019, title={A novel synthetic-genetic-array-based yeast one-hybrid system for high discovery rate and short processing time}, volume={29}, ISSN={["1549-5469"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85071056042&partnerID=MN8TOARS}, DOI={10.1101/gr.245951.118}, abstractNote={Eukaryotic gene expression is often tightly regulated by interactions between transcription factors (TFs) and their DNA cis targets. Yeast one-hybrid (Y1H) is one of the most extensively used methods to discover these interactions. We developed a high-throughput meiosis-directed yeast one-hybrid system using the Magic Markers of the synthetic genetic array analysis. The system has a transcription factor–DNA interaction discovery rate twice as high as the conventional diploid-mating approach and a processing time nearly one-tenth of the haploid-transformation method. The system also offers the highest accuracy in identifying TF–DNA interactions that can be authenticated in vivo by chromatin immunoprecipitation. With these unique features, this meiosis-directed Y1H system is particularly suited for constructing novel and comprehensive genome-scale gene regulatory networks for various organisms.}, number={8}, journal={GENOME RESEARCH}, author={Yeh, Chung-Shu and Wang, Zhifeng and Miao, Fang and Ma, Hongyan and Kao, Chung-Ting and Hsu, Tzu-Shu and Yu, Jhong-He and Hung, Er-Tsi and Lin, Chia-Chang and Kuan, Chen-Yu and et al.}, year={2019}, month={Aug}, pages={1343–1351} }
 @article{yan_liu_kim_liu_huang_yang_lin_chen_yang_wang_et al._2019, title={CAD1 and CCR2 protein complex formation in monolignol biosynthesis in Populus trichocarpa}, volume={222}, ISSN={["1469-8137"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85055556739&partnerID=MN8TOARS}, DOI={10.1111/nph.15505}, abstractNote={Lignin is the major phenolic polymer in plant secondary cell walls and is polymerized from monomeric subunits, the monolignols. Eleven enzyme families are implicated in monolignol biosynthesis. Here, we studied the functions of members of the cinnamyl alcohol dehydrogenase (CAD) and cinnamoyl-CoA reductase (CCR) families in wood formation in Populus trichocarpa, including the regulatory effects of their transcripts and protein activities on monolignol biosynthesis. Enzyme activity assays from stem-differentiating xylem (SDX) proteins showed that RNAi suppression of PtrCAD1 in P. trichocarpa transgenics caused a reduction in SDX CCR activity. RNAi suppression of PtrCCR2, the only CCR member highly expressed in SDX, caused a reciprocal reduction in SDX protein CAD activities. The enzyme assays of mixed and coexpressed recombinant proteins supported physical interactions between PtrCAD1 and PtrCCR2. Biomolecular fluorescence complementation and pull-down/co-immunoprecipitation experiments supported a hypothesis of PtrCAD1/PtrCCR2 heterodimer formation. These results provide evidence for the formation of PtrCAD1/PtrCCR2 protein complexes in monolignol biosynthesis in planta.}, number={1}, journal={NEW PHYTOLOGIST}, author={Yan, Xiaojing and Liu, Jie and Kim, Hoon and Liu, Baoguang and Huang, Xiong and Yang, Zhichang and Lin, Ying-Chung Jimmy and Chen, Hao and Yang, Chenmin and Wang, Jack P. and et al.}, year={2019}, month={Apr}, pages={244–260} }
 @article{shi_wang_lin_li_sun_chen_sederoff_chiang_2017, title={Tissue and cell-type co-expression networks of transcription factors and wood component genes in Populus trichocarpa}, volume={245}, ISSN={["1432-2048"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85009291513&partnerID=MN8TOARS}, DOI={10.1007/s00425-016-2640-1}, abstractNote={Co-expression networks based on transcriptomes of Populus trichocarpa major tissues and specific cell types suggest redundant control of cell wall component biosynthetic genes by transcription factors in wood formation. We analyzed the transcriptomes of five tissues (xylem, phloem, shoot, leaf, and root) and two wood forming cell types (fiber and vessel) of Populus trichocarpa to assemble gene co-expression subnetworks associated with wood formation. We identified 165 transcription factors (TFs) that showed xylem-, fiber-, and vessel-specific expression. Of these 165 TFs, 101 co-expressed (correlation coefficient, r > 0.7) with the 45 secondary cell wall cellulose, hemicellulose, and lignin biosynthetic genes. Each cell wall component gene co-expressed on average with 34 TFs, suggesting redundant control of the cell wall component gene expression. Co-expression analysis showed that the 101 TFs and the 45 cell wall component genes each has two distinct groups (groups 1 and 2), based on their co-expression patterns. The group 1 TFs (44 members) are predominantly xylem and fiber specific, and are all highly positively co-expressed with the group 1 cell wall component genes (30 members), suggesting their roles as major wood formation regulators. Group 1 TFs include a lateral organ boundary domain gene (LBD) that has the highest number of positively correlated cell wall component genes (36) and TFs (47). The group 2 TFs have 57 members, including 14 vessel-specific TFs, and are generally less correlated with the cell wall component genes. An exception is a vessel-specific basic helix-loop-helix (bHLH) gene that negatively correlates with 20 cell wall component genes, and may function as a key transcriptional suppressor. The co-expression networks revealed here suggest a well-structured transcriptional homeostasis for cell wall component biosynthesis during wood formation.}, number={5}, journal={PLANTA}, author={Shi, Rui and Wang, Jack P. and Lin, Ying-Chung and Li, Quanzi and Sun, Ying-Hsuan and Chen, Hao and Sederoff, Ronald R. and Chiang, Vincent L.}, year={2017}, month={May}, pages={927–938} }
 @article{wang_chuang_loziuk_chen_lin_shi_qu_muddiman_sederoff_chiang_2015, title={Phosphorylation is an on/off switch for 5-hydroxyconiferaldehyde O-methyltransferase activity in poplar monolignol biosynthesis}, volume={112}, ISSN={0027-8424 1091-6490}, url={http://dx.doi.org/10.1073/PNAS.1510473112}, DOI={10.1073/pnas.1510473112}, abstractNote={Significance}, number={27}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Wang, Jack P. and Chuang, Ling and Loziuk, Philip L. and Chen, Hao and Lin, Ying-Chung and Shi, Rui and Qu, Guan-Zheng and Muddiman, David C. and Sederoff, Ronald R. and Chiang, Vincent L.}, year={2015}, month={Jun}, pages={8481–8486} }
 @article{li_lin_li_shi_lin_chen_chuang_qu_sederoff_chiang_2014, title={A robust chromatin immunoprecipitation protocol for studying transcription factor-DNA interactions and histone modifications in wood-forming tissue}, volume={9}, ISSN={["1750-2799"]}, DOI={10.1038/nprot.2014.146}, abstractNote={Woody cells and tissues are recalcitrant to standard chromatin immunoprecipitation (ChIP) procedures. However, we recently successfully implemented ChIP in wood-forming tissue of the model woody plant Populus trichocarpa. Here we provide the detailed ChIP protocol optimized for wood-forming tissue that we used in those studies. By using stem-differentiating xylem (SDX; a wood-forming tissue), we identified all steps that were ineffective in standard ChIP protocols and systematically modified them to develop and optimize a robust ChIP protocol. The protocol includes tissue collection, cross-linking, nuclear isolation, chromatin extraction, DNA fragmentation, immunoprecipitation, DNA purification and sequence analysis. The protocol takes 2.5 d to complete and allows a robust 8-10-fold enrichment of transcription factor (TF)-bound genomic fragments (~150 ng/g of SDX) over nonspecific DNAs. The enriched DNAs are of high quality and can be used for subsequent PCR and DNA-seq analyses. We used this protocol to identify genome-wide specific TF-DNA interactions during wood formation and histone modifications associated with regulation of wood formation. Our protocol, which may be suitable for many tissue types, is so far the only working ChIP system for wood-forming tissue.}, number={9}, journal={NATURE PROTOCOLS}, author={Li, Wei and Lin, Ying-Chung and Li, Quanzi and Shi, Rui and Lin, Chien-Yuan and Chen, Hao and Chuang, Ling and Qu, Guan-Zheng and Sederoff, Ronald R. and Chiang, Vincent L.}, year={2014}, month={Sep}, pages={2180–2193} }
 @article{lin_li_chen_li_sun_shi_lin_wang_chen_chuang_et al._2014, title={A simple improved-throughput xylem protoplast system for studying wood formation}, volume={9}, ISSN={["1750-2799"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84907026654&partnerID=MN8TOARS}, DOI={10.1038/nprot.2014.147}, abstractNote={Isolated protoplasts serve as a transient expression system that is highly representative of stable transgenics in terms of transcriptome responses. They can also be used as a cellular system to study gene transactivation and nucleocytoplasmic protein trafficking. They are particularly useful for systems studies in which stable transgenics and mutants are unavailable. We present a protocol for the isolation and transfection of protoplasts from wood-forming tissue, the stem-differentiating xylem (SDX), in the model woody plant Populus trichocarpa. The method involves tissue preparation, digestion of SDX cell walls, protoplast isolation and DNA transfection. Our approach is markedly faster and provides better yields than previous protocols; small (milligrams)- to large (20 g)-scale SDX preparations can be achieved in ~60 s, with isolation of protoplasts and their subsequent transfection taking ~50 min. Up to ten different samples can be processed simultaneously in this time scale. Our protocol gives a high yield (~2.5 × 10(7) protoplasts per g of SDX) of protoplasts sharing 96% transcriptome identity with intact SDX.}, number={9}, journal={NATURE PROTOCOLS}, author={Lin, Ying-Chung and Li, Wei and Chen, Hao and Li, Quanzi and Sun, Ying-Hsuan and Shi, Rui and Lin, Chien-Yuan and Wang, Jack P. and Chen, Hsi-Chuan and Chuang, Ling and et al.}, year={2014}, month={Sep}, pages={2194–2205} }
 @article{lin_li_sun_kumari_wei_li_tunlaya-anukit_sederoff_chiang_2013, title={SND1 Transcription Factor-Directed Quantitative Functional Hierarchical Genetic Regulatory Network in Wood Formation in Populus trichocarpa}, volume={25}, ISSN={["1532-298X"]}, DOI={10.1105/tpc.113.117697}, abstractNote={Novel methods were developed and demonstrated for the discovery of genetic regulatory networks in wood-forming tissues. Transfection of protoplasts from differentiating xylem with the transcription factor gene Ptr-SND1-B1 and novel computational analysis revealed a three-level hierarchical genetic regulatory network that was verified by ChIP and Ptr-SND1-B1 overexpression in transgenic plants. Wood is an essential renewable raw material for industrial products and energy. However, knowledge of the genetic regulation of wood formation is limited. We developed a genome-wide high-throughput system for the discovery and validation of specific transcription factor (TF)–directed hierarchical gene regulatory networks (hGRNs) in wood formation. This system depends on a new robust procedure for isolation and transfection of Populus trichocarpa stem differentiating xylem protoplasts. We overexpressed Secondary Wall-Associated NAC Domain 1s (Ptr-SND1-B1), a TF gene affecting wood formation, in these protoplasts and identified differentially expressed genes by RNA sequencing. Direct Ptr-SND1-B1–DNA interactions were then inferred by integration of time-course RNA sequencing data and top-down Graphical Gaussian Modeling–based algorithms. These Ptr-SND1-B1-DNA interactions were verified to function in differentiating xylem by anti-PtrSND1-B1 antibody-based chromatin immunoprecipitation (97% accuracy) and in stable transgenic P. trichocarpa (90% accuracy). In this way, we established a Ptr-SND1-B1–directed quantitative hGRN involving 76 direct targets, including eight TF and 61 enzyme-coding genes previously unidentified as targets. The network can be extended to the third layer from the second-layer TFs by computation or by overexpression of a second-layer TF to identify a new group of direct targets (third layer). This approach would allow the sequential establishment, one two-layered hGRN at a time, of all layers involved in a more comprehensive hGRN. Our approach may be particularly useful to study hGRNs in complex processes in plant species resistant to stable genetic transformation and where mutants are unavailable.}, number={11}, journal={PLANT CELL}, author={Lin, Ying-Chung and Li, Wei and Sun, Ying-Hsuan and Kumari, Sapna and Wei, Hairong and Li, Quanzi and Tunlaya-Anukit, Sermsawat and Sederoff, Ronald R. and Chiang, Vincent L.}, year={2013}, month={Nov}, pages={4324–4341} }
 @article{wang_shuford_li_song_lin_sun_chen_williams_muddiman_sederoff_et al._2012, title={Functional redundancy of the two 5-hydroxylases in monolignol biosynthesis of Populus trichocarpa: LC-MS/MS based protein quantification and metabolic flux analysis}, volume={236}, ISSN={["1432-2048"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84865584315&partnerID=MN8TOARS}, DOI={10.1007/s00425-012-1663-5}, abstractNote={Flowering plants have syringyl and guaiacyl subunits in lignin in contrast to the guaiacyl lignin in gymnosperms. The biosynthesis of syringyl subunits is initiated by coniferaldehyde 5-hydroxylase (CAld5H). In Populus trichocarpa there are two closely related CAld5H enzymes (PtrCAld5H1 and PtrCAld5H2) associated with lignin biosynthesis during wood formation. We used yeast recombinant PtrCAld5H1 and PtrCAld5H2 proteins to carry out Michaelis-Menten and inhibition kinetics with LC-MS/MS based absolute protein quantification. CAld5H, a monooxygenase, requires a cytochrome P450 reductase (CPR) as an electron donor. We cloned and expressed three P. trichocarpa CPRs in yeast and show that all are active with both CAld5Hs. The kinetic analysis shows both CAld5Hs have essentially the same biochemical functions. When both CAld5Hs are coexpressed in the same yeast membranes, the resulting enzyme activities are additive, suggesting functional redundancy and independence of these two enzymes. Simulated reaction flux based on Michaelis-Menten kinetics and inhibition kinetics confirmed the redundancy and independence. Subcellular localization of both CAld5Hs as sGFP fusion proteins expressed in P. trichocarpa differentiating xylem protoplasts indicate that they are endoplasmic reticulum resident proteins. These results imply that during wood formation, 5-hydroxylation in monolignol biosynthesis of P. trichocarpa requires the combined metabolic flux of these two CAld5Hs to maintain adequate biosynthesis of syringyl lignin. The combination of genetic analysis, absolute protein quantitation-based enzyme kinetics, homologous CPR specificity, SNP characterization, and ER localization provides a more rigorous basis for a comprehensive systems understanding of 5-hydroxylation in lignin biosynthesis.}, number={3}, journal={PLANTA}, publisher={Springer Science + Business Media}, author={Wang, Jack P. and Shuford, Christopher M. and Li, Quanzi and Song, Jina and Lin, Ying-Chung and Sun, Ying-Hsuan and Chen, Hsi-Chuan and Williams, Cranos M. and Muddiman, David C. and Sederoff, Ronald R. and et al.}, year={2012}, month={Sep}, pages={795–808} }
 @article{li_lin_sun_song_chen_zhang_sederoff_chiang_2012, title={Splice variant of the SND1 transcription factor is a dominant negative of SND1 members and their regulation in Populus trichocarpa}, volume={109}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.1212977109}, abstractNote={
            Secondary Wall-Associated NAC Domain 1s (SND1s) are transcription factors (TFs) known to activate a cascade of
            TF
            and pathway genes affecting secondary cell wall biosynthesis (xylogenesis) in
            Arabidopsis
            and poplars. Elevated SND1 transcriptional activation leads to ectopic xylogenesis and stunted growth. Nothing is known about the upstream regulators of
            SND1
            . Here we report the discovery of a stem-differentiating xylem (SDX)-specific alternative
            SND1
            splice variant,
            PtrSND1
            -
            A2
            
              IR
            
            , that acts as a dominant negative of SND1 transcriptional network genes in
            Populus trichocarpa
            .
            PtrSND1
            -
            A2
            
              IR
            
            derives from
            PtrSND1-A2
            , one of the four fully spliced
            PtrSND1
            gene family members (
            PtrSND1
            -
            A1
            , -
            A2
            , -
            B1
            , and -
            B2
            ). Each full-size PtrSND1 activates its own gene, and all four full-size members activate a common
            MYB
            gene (
            PtrMYB021
            ). PtrSND1-A2
            IR
            represses the expression of its
            PtrSND1
            member genes and
            PtrMYB021
            . Repression of the autoregulation of a TF family by its only splice variant has not been previously reported in plants. PtrSND1-A2
            IR
            lacks DNA binding and transactivation abilities but retains dimerization capability. PtrSND1-A2
            IR
            is localized exclusively in cytoplasmic foci. In the presence of any full-size PtrSND1 member, PtrSND1-A2
            IR
            is translocated into the nucleus exclusively as a heterodimeric partner with full-size PtrSND1s. Our findings are consistent with a model in which the translocated PtrSND1-A2
            IR
            lacking DNA-binding and transactivating abilities can disrupt the function of full-size PtrSND1s, making them nonproductive through heterodimerization, and thereby modulating the SND1 transcriptional network. PtrSND1-A2
            IR
            may contribute to transcriptional homeostasis to avoid deleterious effects on xylogenesis and plant growth.
          }, number={36}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Li, Quanzi and Lin, Ying-Chung and Sun, Ying-Hsuan and Song, Jian and Chen, Hao and Zhang, Xing-Hai and Sederoff, Ronald R. and Chiang, Vincent L.}, year={2012}, month={Sep}, pages={14699–14704} }