Project description:Chromatin, in addition to its purely structural functions, is considered a major regulatory system coordinating various genetic networks in eukaryotes. Constant changes of gene expression programs are especially important for plants, which have to respond to environment by modulating their growth and development during whole lifetime. External and developmental signals can be transmitted through signaling cascades to chromatin remodeling complexes like SWI/SNF, which alter chromatin structure by moving, ejecting or restructuring nucleosomes. Genetic studies in Arabidopsis thaliana revealed that SWI/SNF chromatin remodeling complexes are critical for proper plant development and growth. Especially, BRM, a catalytic subunit of the complex, was shown to directly regulate several genes with important functions in leaf development, flowering initiation, as well as gibberellin and abscisic acid signaling. In this study, we profiled BRM global binding regions in Arabidopsis genome by ChIP-chip analysis. We found that BRM can bind to thousands of genes, many of which have key functions in hormone and stress signaling.
Project description:A genome-wide transcriptome analysis showed that altering ZmPIN1a expression led to wide-ranging gene expression changes. When comparing overexpression lines A17 with the WT, 2975 genes were differentially expressed with 793 up-regulated and 2182 down-regulated in the leaves, and 2129 genes were differentially expressed with 938 up-regulated and 1191 down-regulated in the roots. GO analysis indicated that these differentially expressed genes participate in multiple biological processes from hormone signaling to metabolism. The local biosynthesis, PAT and signaling of auxin were altered; some was directly employed in plant developments such as AUX/IAA, ARFs and genes related to PAT. The genes involved in ethylene, GA, BR CK and ABA metabolism and signaling were altered as well. These phytohormones were also confirmed as key regulators in plant development and abiotic stress responses. Some of the differentially expressed genes between A17 and WT were identified as Arabidopsis root morphology and development mutant genes. These mutants were abnormal in their plant hormone synthesis and signaling, calcium-mediated signaling, MAP kinase signaling, transcription factors, membrane transporters etc. This finding suggested that ZmPIN1a overexpression led to a change of the auxin signaling transduction and even the metabolism of auxin and the metabolism and signaling of other hormones. These events led to changes in the expression of numerous genes and resulted in the modification of plant morphology, especially the root architecture. Maize (Zea mays L.) inbred line DH4866, its ZmPIN1a sense transgenic lines A17 and antisense transgenic lines a55 were used in this study. The transcriptome by altering ZmPIN1a expression was done by comparing the transcriptome of WT and transgenic lines both in root and leaf of V3 stage plants.
Project description:Plants need to be able to respond to changes quickly due to the inability of a plant to change location. Hormones within the plant signal for these transcriptional changes that will affect the plant's ability to survive. Strigolactone is a plant hormone that was more recently discovered so has a less detailed understanding of what genes it regulates, compared to other plant hormones. First published in Brewer et al 2016, PNAS We used microarrays to determine transcriptional responses in strigolactone mutants and in wild-type plants with various physiological treatment which affect hormone levels over 24 hours.
Project description:A genome-wide transcriptome analysis showed that altering ZmPIN1a expression led to wide-ranging gene expression changes. When comparing overexpression lines A17 with the WT, 2975 genes were differentially expressed with 793 up-regulated and 2182 down-regulated in the leaves, and 2129 genes were differentially expressed with 938 up-regulated and 1191 down-regulated in the roots. GO analysis indicated that these differentially expressed genes participate in multiple biological processes from hormone signaling to metabolism. The local biosynthesis, PAT and signaling of auxin were altered; some was directly employed in plant developments such as AUX/IAA, ARFs and genes related to PAT. The genes involved in ethylene, GA, BR CK and ABA metabolism and signaling were altered as well. These phytohormones were also confirmed as key regulators in plant development and abiotic stress responses. Some of the differentially expressed genes between A17 and WT were identified as Arabidopsis root morphology and development mutant genes. These mutants were abnormal in their plant hormone synthesis and signaling, calcium-mediated signaling, MAP kinase signaling, transcription factors, membrane transporters etc. This finding suggested that ZmPIN1a overexpression led to a change of the auxin signaling transduction and even the metabolism of auxin and the metabolism and signaling of other hormones. These events led to changes in the expression of numerous genes and resulted in the modification of plant morphology, especially the root architecture.
Project description:Arabidopsis thaliana plants that have experienced an initial exposure to dehydration stress (“trained plants”) have an increased ability to maintain leaf relative water content (RWC) during subsequent stresses than plants experiencing the stress for the first time and transcription of selected dehydration response genes is altered during successive exposures to dehydration stress. This physiological and transcriptional behavior of trained plants is consistent with a “memory “of an earlier stress. It is unknown whether such memory is present in other Angiosperm lineages and whether it is an evolutionarily conserved response to stress (see E-GEOD-48235). Here, we analyzed the behavior and transcriptomes of maize (Zea mays) plants experiencing multiple dehydration stresses and compare them with responses of the evolutionarily distant A. thaliana. We found structurally related genes in maize that displayed the same memory-type responses as in A. thaliana, providing evidence of the conservation of function and transcriptional memory in the evolution of plants’ dehydration stress response systems. Similar to A. thaliana, trained Z. mays plants retained higher RWC during dehydration stress than untrained plants, due in part to maintaining reduced stomatal conductance, despite full recovery of RWC, after the first stress. Divergent transcriptional memory responses were also expressed, suggesting diversification of function among stress memory genes. Some dehydration stress memory genes were also shared with other stress and hormone responding pathways, indicating complex and dynamic interactions between different plant signaling networks. The results provide new insight into how plants respond to multiple dehydration stresses and provide a platform for studies of the functions of memory genes in adaptive responses to water deficit in monocot and eudicot plants . For each condition (water, S1, and S3) the transcriptome was sequenced for two replicates. The watered condition is considered the control.
Project description:We characterized the global response of plants carrying a mitochondrial dysfunction induced by the expression of the unedited form of the ATP synthase 9 subunit. The u-ATP9 transgene driven by A9 and Apetala3 promoters induce mitochondrial dysfunction revealed by a decrease in both oxygen uptake and ATP levels, with an increase in ROS and a concomitant oxidative stress response. The transcriptome analysis of young Arabidopsis flowers, validated by RT-PCR and enzymatic or functional tests, show dramatic changes in u-ATP9 plants. Both lines present a modification in the expression of several genes involved in carbon, lipid and cell wall metabolism, suggesting that an important metabolic readjustment occurs in plants with a mitochondrial dysfunction. Interestingly, transcript levels involved in mitochondrial biogenesis, protein synthesis, and degradation are affected. Moreover, several mRNA levels for transcription factors and DNA binding proteins were also changed. Some of them are involved in stress and hormone response, suggesting that several signaling pathways overlap. Indeed, the transcriptome data reveal that the mitochondrial dysfunction dramatically alters genes involved in signaling pathways, including those involved in ethylene, absicic acid and auxin signal transduction. Our data suggest that the mitochondrial dysfunction model used in this rapport may be useful to uncover the retrograde signaling mechanism between the nucleus and mitochondria in plant cells.
Project description:Tricoderma genus fungi are referred to as "biostimulants" because they promote plant development and provide disease resistance. In this study, utilizing a conventional transcriptome analysis and gene co-expression network analysis after conventionally stimulating Arabidopsis thaliana with Trichoderma atroviride or Trichoderma virens. We found by differential expression and functional enrichment analyses that the transcriptome analysis of the plant during interactions, T. atroviride and T. virens, were involved in the reduction of reactive oxygen species, defense mechanisms against pathogens, and hormone signaling pathways. T. virens, as opposed to T. atroviride, was more effective at downregulating genes related to terpenoid metabolism, root development, and chemical homeostasis. We were able to find functional gene modules through network analysis that closely link plant defense mechanisms with hypoxia mechanisms. We discovered a transcription factor (locus AT2G47520) with two functional domains of interest: a DNA-binding domain and an N-terminal cysteine needed for protein stability under hypoxia. We discovered that the transcription factor can bind to the promoter sequence of the GCC-box gene that is connected to pathogenesis by positioned weight matrix analysis.