Auxin-independent NAC pathway regulates cell wall metabolism in response to explant-specific wounding during regeneration in Arabidopsis I
ABSTRACT: In this study, through a genome-wide transcriptome analysis of wounding in the leaf explant, we identified NAC1 (petunia NAM and Arabidopsis ATAF1, ATAF2, and CUC2) family transcription factor gene that acts in response to wounding and functions in regulation of cell wall metabolism. RNA-Seq analysis of the genes up-regulated by NAC1
Project description:In this study, through a genome-wide transcriptome analysis of wounding in the leaf explant, we identified NAC1 (petunia NAM and Arabidopsis ATAF1, ATAF2, and CUC2) family transcription factor gene that acts in response to wounding and functions in regulation of cell wall metabolism. RNA-Seq analysis of the wound site of leaf explants and leaf residu
Project description:Polycomb Group Proteins (PcGs) is critical in defining the epigenetic blueprint for animal and plant development. In plants, loss of different PcGs display both common and unique phenotypic defects, yet little is known about how these are established. Here, based on quantitative comparison of epigenomics data from mutants of key PcG components in Arabidopsis seedlings, we found that the PcG partners of CURLY LEAF (CLF), one of the major plant H3K27 trimethyltransferases, determines its selectivity in repressing gene loci involved in distinct developmental programs. The non-redundant role of CLF in determining flower development is specifically associated with HETEROCHROMATIN PROTEIN1 (LHP1). This context dependent effect of CLF corresponds well with tissue-biased target gene expression, and importantly, to differential co-occupancy of transcription factors, such as MADS box and B3-domain transcription factors. These results provide valuable insight as to the dynamic interplay between different PcGs and their collaborative control of plant development. To compare the effect of different PcGs on epigenetic structure from the genome-wide scale, we used chromatin immunoprecipitation followed by high-throughtput sequencing (ChIP-seq) to characterize the genome-wide binding profile of H3K27me3 in Col, clf-29, tfl2-2, atbmi1a/b and atring1a/b ; To investigate the functional consequence of the distinct H3K27me3 profile controlled by different combinations of PcGs, we characterized the transcriptome change in PcG mutants, including Col, clf-29, tfl2-2, lhp1-6, atbmi1a/b, atring1a/b, and clf29swn21.
Project description:Using a transgenic line expressing HA-tagged ATAF1 uncovered >400 ChIP-seq peaks in ATAF1-HA plants compared to Col-0 wild-type plants. Only a small sub-set of the candidate peaks could be verified using ChIP-qpcr or EMSA. Among the verified peaks we uncovered the key ABA biosynthetic gene NCED3 as a target of ATAF1 ChIP was performed using anti-HA antibodies on wild-type Col-0 plants and plants expressing HA-tagged ATAF1
Project description:Spider mites, including the two-spotted spider mite (Tetranychus urticae, TSSM) and the Banks grass mite (Oligonychus pratensis, BGM), are becoming increasingly important agricultural pests. The TSSM is an extreme generalist documented to feed on more than 1100 plant hosts. In contrast, the BGM is a grass specialist, with hosts including important cereal crops like maize, wheat, sorghum and barley. Historically, studies of plant-herbivore interactions have focused largely on insects. However, far less is known about plant responses to spider mite herbivores, especially in grasses, and whether responses differ between generalists and specialists. To identify plant defense pathways responding to spider mites, we collected time course RNA-seq data from barley (Hordeum vulgare L.) infested with TSSMs and BGMs. Additionally, and as a comparison to the physical damage caused by spider mite feeding, a wounding treatment was also included. The experiment was performed with four biological replicates across each of the following (28 samples in total): no infestation (C, control), 2hr after wounding (W2), 24hr after wounding (W24), 2hr after TSSM infestation (T2), 24hr after TSSM infestation (T24), 2hr after BGM infestation (B2), and 24hr after BGM infestation (B24).
Project description:RELATIVE OF EARLY FLOWERING 6 (REF6, also known as JMJ12) counteracts Polycomb mediated gene silencing through demethylating histone H3 lysine 27 trimethylation (H3K27me3) in Arabidopsis. Genome-wide analysis has demonstrated that REF6 dependent H3K37me3 demethylation occurs on hundreds of genes. However, how these genes are selectively subjected to H3K27me3 demethylation remains elusive. Here we show that a tandem array of four Cys2-His2 zinc finger domains (C2H2-ZF) at REF6 C-terminus are essential for REF6 function. Mechanistically, we find that C2H2-ZF cluster can directly recognize a specific DNA sequence motif, and is essential for binding of REF6 to its targets. In addition, we demonstrate that CUP-SHAPED COTYLEDON 1 (CUC1) and CUC3 harbor such sequence motif and are direct targets of REF6; while their close homolog, CUC2, without such binding motif is not bound by REF6. Furthermore, REF6 is essential for proper H3K27me3 level at CUC1 locus, CUC1 activation and cotyledon separation. Collectively, our study reveals not only a novel mechanism of H3K27me3 demethylase genome targeting to counteract Polycomb silencing, but also a new function of H3K27me3 demethylation in organ boundary formation. All seeds, except for H3K9me2 ChIP-seq, were grown on 1/2MS plate at 23°C under long day condition. 12 day after germination (12DAG), whole seedling were harvested for ChIP-seq. anti-HA ChIP-seq were performed with three samples: Col (WT,Negtive control), REF6-HA(REF6p::REF6-HA ref6-1),REF6-ZnF-HA(REF6p::REF6-ZnF-HA ref6-1). anti-H3K27me3 ChIP-seq were performed with four samples: Col (WT), ref6-1 (mutant), REF6-HA(REF6p::REF6-HA ref6-1),REF6-ZnF-HA(REF6p::REF6-ZnF-HA ref6-1).For H3K9me2 ChIP-seq, plants were grown in soil at 23°C under long day condition. Aerial part of plants were harvested for ChIP-seq 28d after germination.
Project description:Plants have evolved to possess adaptation mechanism to cope with drought stress by reprograming transcriptional networks through drought responsive transcription factors, which in turn mediate morphological and physiological changes. NAM, ATAF1-2, and CUC2 (NAC) transcription factors are known to be associated with various developmental processes and stress tolerance. In this study, we functionally characterized the rice drought responsive NAC transcription factor OsNAC14. OsNAC14 was predominantly induced at meiosis stage, and induced by drought, high salinity, ABA and low temperature in leaves than roots. Overexpression of OsNAC14 resulted in drought tolerance at the vegetative growth stage and enhanced filling rate at vegetative growth. OsNAC14 overexpression elevated expression of genes related to DNA damage repair, defense response, strigolactone biosynthesis, which correlated with resistance to drought tolerance. Furthermore, OsNAC14 directly bound to the promoter of drought inducible OsRAD51A1, a key component in homologous recombination in DNA repair system. These results indicate that OsNAC14 mediate drought tolerance by recruiting factors involved in DNA damage repair and defense response to enable plant to protect from cellular damage caused by drought stress, thereby provide mechanism for drought tolerance. Overall design: RNA-seq using leaves of NT (nontransgenic plants), PGD1:OsNAC14 transgenic plants that were generated by deep sequencing using Illumina Hiseq 2500.
Project description:Cell differentiation is an essential process of normal development by which a stem cell or progenitor cell becomes a post-mitotic, specialized cell with unique morphology and function. Also, it has long been recognized that differentiation is associated with a marked reduction in DNA damage response at the global level. The molecular basis for the coordination between cell cycle exit, acquirement of specialized structure and function, and attenuation of DNA damage response during differentiation is not well understood. We have conducted a genome-wide analysis of the HOXC9-induced neuronal differentiation program in human neuroblastoma cells. Gene expression profiling reveals that HOXC9-induced differentiation is associated with transcriptional regulation of 2,395 genes, which is characterized by global upregulation of neuronal genes and downregulation of cell cycle and DNA repair genes. Remarkably, genome-wide mapping demonstrates that HOXC9 occupies 40% of these genes, including a large number of genes involved in neuronal differentiation, cell cycle progression and DNA damage response. These findings suggest that HOXC9 directly activates and represses the transcription of distinct sets of genes to coordinate the cellular events characteristic of neuronal differentiation. Two independent preparations of BE(2)-C/Tet-Off/Myc-HOXC9 cells cultured in the absence of doxycycline for 6 days were used for chromatin immunoprecipitation (ChIP) against Myc-tagged HOXC9 and massively parallel sequencing by Illumina Genome Analyzer IIx.
Project description:Global transcriptome patterns were obtained from ATAF1-IOE seedlings at 1 h, 2 h and 5 h after estradiol induction or mock treatment, and from mature ATAF1-IOE leaves at 5 h after estradiol induction or mock treatment. To identify genes rapidly responding to elevated ATAF1 expression estradiol induction experiments were performed on ATAF1-IOE seedlings after 1 h, 2 h and 5 h of ATAF1 induction. In addition, expression profiles were obtained from mature leaves after 5 h of ATAF1 induction.
Project description:au13-03_cuc2 - identification of target genes regulated by cuc2 in a.thaliana shoot apical meristem. - Identification of genes specifically targeted by the CUC2 transcription factor that defines the margins of the floral meristem of Arabidopsis thaliana. - identify genes specifically targeted by CUP-SHAPED COTYLEDON 2 (CUC2), a transcription factor required for embryonic shoot meristem formation and specification of the organ boundary in A.thaliana Overall design: 3 dye-swap - genotype comparaison
Project description:Plants show a remarkable plasticity to adapt their root architecture to biotic and abiotic constraints of the soil environment. Although some of these modifications are fine-tuned by miRNAs, there are still shadow zones in these regulations. In the model legume Medicago truncatula, we analyzed the small RNA (smRNA) transcriptome of roots submitted to symbiotic and pathogenic interactions. Mapping on the genome and prediction of pre-miRNA hairpins allowed the identification of 416 candidates. Out of them, we found known and novel variants of 77 miRNA families, already reported in miRBase. In addition, thanks stringent criteria of miRNA prediction, 53 mtr-miRNAs were discovered, including 27 putative miRtrons. Exploring polymorphism in 26 M. truncatula ecotypes, higher polymorphism was observed in conserved rather than legume-specific miRNA genes. An average of 19 targets, mainly involved in environmental responses and signaling, was predicted per novel miRNA. In addition, taking advantage of our large number of smRNA libraries, we identified sets of miRNAs responsive to root pathogens or to symbiotic interactions and the related Nod and myc-LCO signals. 23 libraries of small RNA (smRNA) of roots submitted to symbiotic and pathogenic interactions.