Project description:Global gene-expression profiles of WT Arabidopsis (Col-0), npr1-1, and hac1/5 were generated by RNA seq to study functional relationship between NPR1 and HACs in plant defense
Project description:Genome-wide H3Ac maps of WT (Col-0), npr1-1, and hac1/5 leaves were generated by chromatin immunoprecipitation (ChIP) followed by high-throughput DNA sequencing (ChIP seq) to understand the role of HATs in the reprogramming of the epigenome during immune response.
Project description:Genome-wide direct targets of Arabidopsis NPR1 and HAC1 were identified by chromain immunoprecipitation followed by sequencing (ChIP-seq). For the study, we used Arabidopsis expressing NPR1:GFP or HAC1:mCherry under native NPR1 or HAC1 promoter, respectively. To identify direct targets both under salicylic acid-treated and untreated conditions, we performed ChIP-seq by using 2,6-dichloroisonicotinc acid (INA; synthetic SA analog)-treated and untreated NPR1:GFP or HAC1:mCherry transgenic Arabidopsis plants.
Project description:Nutrient remobilization during leaf senescence nourishes the growing plant. Understanding the regulation of this process is essential for reducing our dependence on nitrogen fertilizers and increasing agricultural sustainability. Our lab is interested in chromatin changes that accompany the transition to leaf senescence. Previously, darker green leaves were reported for Arabidopsis thaliana hac1 mutants, defective in a gene encoding a histone acetyltransferase in the CREB-binding protein family. Here, we show that two Arabidopsis hac1 alleles display delayed age-related developmental senescence, but have normal dark-induced senescence. Using a combination of ChIP-seq for H3K9ac and RNA-seq for gene expression, we identified 44 potential HAC1 targets during age-related developmental senescence. Genetic analysis demonstrated that one of these potential targets, ERF022, is a positive regulator of leaf senescence. ERF022 is regulated additively by HAC1 and MED25, suggesting MED25 may recruit HAC1 to the ERF022 promoter to increase its expression in older leaves.
Project description:Col-0 floral stem was grafted on the msh1 mutant (Col-0/msh1); on the dcl2,3,4,msh1 quadruple mutant (Col-0/dcl2,3,4,msh1); on Col-0 (Col-0/Col-0). Seeds were collected from the grafted Col-0 scion after grafts were established. Seed coming from the graft then were grown on the peat mix, leaf tissue was collected at the bolting and used for the total RNA sequencing.
Project description:ABSTRACT: Inorganic arsenic is a carcinogen and its ingestion in foods such as rice presents a significant risk to human health. Plants chemically reduce arsenate to arsenite. Using genome-wide association (GWA) mapping of loci controlling natural variation in arsenic accumulation in Arabidopsis thaliana allowed us to identify the arsenate reductase required for this reduction, which we named High Arsenic Content1 (HAC1). Complementation verified the identity of HAC1, and expression in Escherichia coli lacking a functional arsenate reductase confirmed the arsenate reductase activity of HAC1. The HAC1 protein accumulates in the epidermis, the outer cell layer of the root, and also in the pericycle cells surrounding the central vascular tissue. Plants lacking HAC1 lose their ability to efflux arsenite from roots, leading to both increased transport of arsenic into the central vascular tissue and on into the shoot. HAC1 therefore functions to reduce arsenate to arsenite in the outer cell layer of the root, facilitating efflux of arsenic as arsenite back into the soil to limit its accumulation in the root and transport to the shoot. Arsenate reduction by HAC1 in the pericycle may play a role in limiting arsenic loading into the xylem. Loss of HAC1 encoded arsenic reduction leads to a significant increase in arsenic accumulation in shoots causing an increased sensitivity to arsenate toxicity. We also confirmed the previous observation that the ACR2 arsenate reductase in A. thaliana plays no detectable role in arsenic metabolism. Further, ACR2 does not interact epistatically with HAC1, since arsenic metabolism in the acr2 hac1 double mutant is disrupted in an identical manner to that described for the hac1 single mutant. Our identification of HAC1 and its associated natural variation provides an important new resource for the development of low arsenic containing food stuffs such as rice. Hybridizations from a set of Bulk Segregant analysis. We measured the elemental profile of 315 F2 plants from a cross between the high arsenic Arabidopsis thaliana accession Kr-0 and the the low arsenic accession Col-0, data available at www.ionomicshub.org <http://www.ionomicshub.org>. Leaves from the 59 highest and 61 lowest arsenic accumulating plants (calculated as a percentage of the Col-0 accumulation in the same growth tray) were pooled and the genomic DNA was extracted using Qiagen kits.
Project description:Col-0 floral stem was grafted on the msh1 mutant (Col-0/msh1); on the dcl2,3,4,msh1 quadruple mutant (Col-0/dcl2,3,4,msh1); on Col-0 (Col-0/Col-0). Seeds were collected from the grafted Col-0 scion after grafts were established. Seed coming from the graft then were grown on the peat mix, leaf tissue was collected at the bolting and used for the bisulfite sequencing (methylome). Tissue from the msh1 mutant and dcl2,3,4,msh1 quadruple mutants used as rootstocks was similarly collected at the bolting stage and used for the bisulfite sequencing.
Project description:To investigate the deposition of HTR5 in Arabidopsis, we analysed genome-wide HTR5 density in the wild-type Col-0 by ChIP-seq. We then performed HTR5 occupancy analysis using data obtained from ChIP-seq of 3 different plants including HA-HTR5/Col-0 and Col-0. Col-0 acted as negative control.