Transcription profiling by array of Arabidopsis root to study gene expression in myb10/myb72 mutants under iron deficiency versus controls.
ABSTRACT: MYB10 and MYB72 are two transcription factors expressed in Arabidopsis roots under iron deficiency. To understand the contribution of these factors, we analyzed gene expression in roots of wild-type (Col) and mutant (myb10myb72 double knockout) seedlings exposed to iron deficiency for 72 hours.
Project description:This SuperSeries is composed of the following subset Series:; GSE10496: Expression analysis of the effect of protoplasting and FACS sorting in roots exposed to iron deficiency (-Fe); GSE10497: Expression analysis of root developmental zones after iron deficiency (-Fe) treatment; GSE10501: Expression analysis of root cell-types after iron deficiency (-Fe) treatment; GSE10502: Time course expression analysis of the iron deficiency (-Fe) response in Arabidopsis roots Experiment Overall Design: Refer to individual Series
Project description:Transcriptional profile of whole roots of wild-type and pye-1 mutants exposed to 24 hours -Fe were generated Global population increases and climate change underscore the need for better comprehension of how plants acquire and process nutrients such as iron. A systems biology approach was taken to elucidate novel regulatory mechanisms involved in plant responses to iron deficiency (-Fe). Using cell-type specific transcriptional profiling we identified a pericycle-specific iron deficiency response, and a previously uncharacterized transcription factor, POPEYE (PYE), that plays an important role in this response. Functional analysis of PYE suggests that it positively regulates growth and development under iron deficient conditions. ChIP-on-chip analysis and transcriptional profiling reveal that PYE helps maintain iron homeostasis by directly and indirectly regulating the expression of ferric reductases, metal ion transporters, iron storage proteins, and other key iron homeostasis genes. In addition to PYE, we also identified a second protein BRUTUS (BTS), which appears to negatively regulate the response to iron deficiency. BTS is a unique putative E3 ligase protein, with metal ion binding and DNA binding domains. PYE and BTS are tightly co-regulated and physically interact with PYE paralogs, one of which is thought to positively regulate expression of genes involved in iron homeostasis. We propose that iron content is sensed within the pericycle where PYE, perhaps in conjunction with BTS and other regulatory proteins, is then activated to control a regulatory network involved in maintaining proper iron distribution in plants. Keywords: Expression analysis To determine how loss of PYE expression affects the transcriptional profile of whole roots, pye-1 mutants and wild-type seeds were germinated under standard growth conditions then transferred to standard media (control, MS media) or iron deficient media (-Fe, 0.3mM Ferrozine in MS media containing no ferrous sulfate). After 24 hours of exposure to +Fe or -Fe whole roots were collected and analyzed.
Project description:Iron (Fe) deficiency is a yield-limiting factor for a variety of field crops across the world and generally results from the interaction of limited soil Fe bioavailability and susceptible genotype cultivation. Tomato, a Strategy I, model plant for Fe deficiency, is an important economical crop. Tomato responses in order to improve Fe uptake are based on acidification of rhizosphere, reduction of Fe3+ to Fe2+ and transport of Fe2+ into the cells. Transcriptional profile obtained by roots (27-d) of 21-d-old tomato plants starved of iron for an additional week was compared with the transcriptional profile obtained for roots (27-d) of 21-d-old tomato plants grown for an additional week at 100 μM Fe. Tomato plants were hydroponically grown in both cases. Three different biological replicates were used for each sample repeating the experiment three times. All samples were obtained pooling roots of six plants (27-d-old).
Project description:We performed a time course analysis (TC data set) of the response of whole seedling roots to -Fe at 6 time points after transfer (3, 6, 12, 24, 48, and 72 hours). Little is known about how developmental cues affect the way cells interpret their environment. Here we characterize the transcriptional response of different cell layers and developmental stages of the Arabidopsis root to high salinity and find that transcriptional responses are highly constrained by developmental parameters. These transcriptional changes lead to the differential regulation of specific biological functions in subsets of cell-layers, several of which correspond to observable physiological changes. We show that known stress pathways primarily control semi-ubiquitous responses and use mutants that disrupt epidermal patterning to reveal cell-layer specific and inter-cell-layer effects. By performing a similar analysis using iron-deprivation we identify common cell-type specific stress responses and environment-independent biological functions that define each cell type. Experiment Overall Design: Seedlings were grown for 5 days before transfer to iron deficient (-Fe) conditions (0.3mM Ferrozine in MS media containing no iron sulfate). Whole roots were harvested at 6 time points after the transfer.
Project description:• Selected soil-borne rhizobacteria can trigger an induced systemic resistance (ISR) that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, the root-specific transcription factor MYB72 is required for the onset of ISR, but is also associated with plant survival under conditions of iron deficiency. Here we investigated the role of MYB72 in both processes. • To identify MYB72 target genes, we analyzed the root transcriptomes of wild-type Col-0, mutant myb72, and complemented 35S:FLAG-MYB72/myb72 plants in response to ISR-inducing Pseudomonas fluorescens WCS417. • Five WCS417-inducible genes were misregulated in myb72 and complemented in 35S:FLAG-MYB72/myb72. Amongst these, we uncovered β-glucosidase BGLU42 as a novel component of the ISR signaling pathway. Overexpression of BGLU42 resulted in constitutive disease resistance, whereas bglu42 was defective in ISR. Furthermore, we found 195 genes to be constitutively upregulated in MYB72-overexpressing roots in the absence of WCS417. Many of these encode enzymes involved in the production of iron-mobilizing phenolic metabolites under conditions of iron deficiency. We provide evidence that BGLU42 is required for their release into the rhizosphere. • Together, this work highlights a thus far unidentified link between the ability of beneficial rhizobacteria to stimulate systemic immunity and mechanisms induced by iron deficiency in host plants. Total 18 samples of RNA extracted from Arabidopsis roots: Three genotypes: 1) Wild-type Arabidopsis thaliana accession Col-0, 2) mutant myb72-2 (Col-0 background), 3) Transgenic 35S:FLAG-MYB72 (oxMYB72) in the myb72-2 background; Two treatments: 1) non-treated control, 2) Roots colonized by beneficial Pseudomonas fluorescens WCS417 rhizobacteria; Replicates: three biological replicates per genotype/treatment combination
Project description:Tomato, a Strategy I model plant for Fe deficiency, is an important economical crop. The transcriptional responses induced by Fe deficiency in tomato roots were previously described (Zamboni et al., 2012). The changes in trascriptome caused by the supply of Fe to plants starved fro 1 week were described in relation to the different nature of chelating agents (Fe-WEHS, Fe-CITRATE and Fe-PS). Transcriptional profile obtained by roots (27-d) of 21-d-old tomato plants starved of iron (0 μM Fe-EDTA) for 1 week and supplied for 1 h with 1 μM of Fe as Fe-WEHS (supply_Fe_WEHS), Fe citrate (supply_Fe_CITRATE) and Fe-PS (supply_Fe_PS). Tomato plants were hydroponically grown in all three case of Fe supply. Three different biological replicates were used for each sample repeating the experiment three times. All samples were obtained pooling roots of six plants (27-d-old).
Project description:Under low iron availability, plants induce the expression of various genes involved in iron uptake and translocation at the transcriptional level. This iron deficiency response is affected by various plant hormones, but the roles of jasmonates in this response are not well-known. We investigated the involvement of jasmonates in rice iron deficiency responses. High rates of jasmonate-inducible genes were induced during the very early stages of iron deficiency treatment in rice roots. Many jasmonate-inducible genes were also negatively regulated by the ubiquitin ligases OsHRZ1 and OsHRZ2 and positively regulated by the transcription factor IDEF1. Ten out of 35 genes involved in jasmonate biosynthesis and signaling were rapidly induced at 3 h of iron deficiency treatment, and this induction preceded that of known iron deficiency-inducible genes involved in iron uptake and translocation. Twelve genes involved in jasmonate biosynthesis and signaling were also upregulated in HRZ-knockdown roots. Endogenous concentrations of jasmonic acid and jasmonoyl isoleucine tended to be rapidly increased in roots in response to iron deficiency treatment, whereas these concentrations were higher in HRZ-knockdown roots under iron-sufficient conditions. Analysis of the jasmonate-deficient cpm2 mutant revealed that jasmonates repress the expression of many iron deficiency-inducible genes involved in iron uptake and translocation under iron sufficiency, but this repression is partly canceled under an early stage of iron deficiency. These results indicate that jasmonate signaling is activated during the very early stages of iron deficiency, which is partly regulated by IDEF1 and OsHRZs.
Project description:The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a master regulator for differentiation of xylem vessels. In order to identify a set of genes regulated by VND7, we carried out a microarray experiment with the Arabidopsis full-genome GeneChip array ATH1 (Affymetrix) for transgenic Arabidopsis roots overexpressing VND7. Experiment Overall Design: Total RNAs were isolated from roots of 5-day-old seedling of transgenic plants overexpressing YFP and VND7-YFP under control of Cauliflower mosaic virus 35S promoter. Three independent biological replicates were performed for each sample.
Project description:we deep-sequenced two small RNA libraries made from V. longisporum infected/non-infected roots and employed Brassica rapa and Brassica oleracea genomes as reference for miRNA prediction and characterization as well. We identified 893 B. napus miRNAs representing 360 conserved and 533 novel miRNAs, and mapped 429 and 464 miRNAs to AA and CC genomes, respectively. Among them, 62 miRNAs were responsive to the V. longisporum infection. two small RNA libraries constructed from V. longsiporum infected and non-infected roots after 6 days were sequenced by Illumina’s Solexa sequencing technology (BGI, China)