Project description:To transcriptionally characterize lateral root development in rice, we subjected the rice LRIS to genome-wide transcript profiling via RNA-sequencing. Taking into account the appearance of the first (stage I primordium) cell divisions starting from 6 hours after NAA treatment, we sampled at 2 hours and at 5 hours after NAA treatment to capture the primary auxin response and the gene expression related to initiation, respectively. Additionally, we sampled at 8 hours, 14 hours and 20 hours, in which the root was highly enriched for stage I, II and III primordia, respectively. As the spatiotemporal assessment of the primordia in the LRIS showed a highly synchronous induction and development of lateral roots in particular in the region just above the root meristem, root sections between 750 µm and 2000 µm from the root tip were microdissected and used for RNA-extraction. To assess possible artefacts induced by the replacement of the medium, we sampled a control before and 2 hours after replacement with NPA containing medium.
Project description:We sorted for GFP+ cells using the enhancer trap line J2632 with the UAS promoter driving the expression of an inducible (by dexamethasone - Dex) constitutive active version of the ARR1 gene (ARR1ΔDDK). We obtained the transcriptional profile of lateral root cap cells
Project description:Lateral root initiation was used as a model system to study the mechanisms behind auxin-induced cell division. Genome-wide transcriptional changes were monitored during the early steps of lateral root initiation. Inclusion of the dominant auxin signaling mutant solitary root1 (slr1) identified genes involved in lateral root initiation that act downstream of the AUX/IAA signaling pathway. Interestingly, key components of the cell cycle machinery were strongly defective in slr1, suggesting a direct link between AUX/IAA signaling and core cell cycle regulation. However, induction of the cell cycle in the mutant background by overexpression of the D-type cyclin (CYCD3;1) was able to trigger complete rounds of cell division in the pericycle that did not result in lateral root formation. Therefore, lateral root initiation can only take place when cell cycle activation is accompanied by cell fate respecification of pericycle cells. The microarray data also yielded evidence for the existence of both negative and positive feedback mechanisms that regulate auxin homeostasis and signal transduction in the pericycle, thereby fine-tuning the process of lateral root initiation. Keywords: time-course wild type vs mutant comparison
Project description:We report the comparison of transcriptomic profiles in specific lateral root tissues for Col-0 wild type and puchi-1 mutant seedlings. Lateral root organogenesis is a key process in plant root system development and adaptation to the environment. To dissect the molecular events occurring during the early phase, we generated time-series transcriptomic datasets profiling lateral root development in puchi-1 and wild type backgrounds. Consistent with a mutually inhibitory mechanism, transcriptomic and reporter analysis revealed meristem-related genes were ectopically expressed during early stages of lateral root primordium formation in puchi-1. We conclude that PUCHI participates to the coordination of lateral root patterning and represses ectopic establishment of meristematic cell identities during early stages of organ development.
Project description:The goal of this experiment was to identify the downstream targets of the GOLVEN6 peptide signaling pathway in Arabidopsis thaliana, specifically during lateral root initiation. Using an estradiol inducible GLV6 overexpression construct in wildtype and rgi1rgi5 double mutant (mutant in receptors for the GLV6 peptide) backgrounds, in combination with gravistimulation induced lateral root formation, the RGI receptor dependent transcriptional effects of GLV6 overexpression were characterized. An estradiol inducible GLV6 overexpression line in a wildtype (iGLV6) and in an rgi1rgi5 double receptor mutant background (rgi1rgi5/iGLV6) were used. 4-day old seedlings of both lines were gravistimulated (vertically grown seedlings were turned counterclockwise by 90°) to induce lateral root initiation in the resulting root bends. 8h after gravistimulation, seedlings of both lines were treated with 2µM of estradiol to induce GLV6 overexpression, or DMSO as a mock treatment. 3h and 6h after treatment, root bends were dissected and collected for RNA-sequencing. This yielded a total of 8 samples per replicate; 3h mock treated iGLV6 (IM3), 3h estradiol treated iGLV6 (IE3), 3h mock treated rgi1rgi5/iGLV6 (RM3), 3h estradiol treated rgi1rgi5/iGLV6 (RE3), 6h mock treated iGLV6 (IM6), 6h estradiol treated iGLV6 (IE6), 6h mock treated rgi1rgi5/iGLV6 (RM6), 6h estradiol treated rgi1rgi5/iGLV6 (RE6). For each sample, 4 replicates were obtained. This setup enabled the comparison of the GLV6 induced transcriptional effects between wildtype and rgi1rgi5 mutants at 2 time points after treatment, in samples that are strongly enriched for lateral root initiation events.
Project description:In the lateral root repression system described by Babé et al. (2012), the first asymetric divisions of pericycle cells preceding lateral root formation are repressed during water deficit treatments. During an 8-hr long treatment, an 8-mm long root segment is formed where LR formation has been repressed. The experiment was designed to monitor changes in gene expression during early events of LR formation in barley using this LR repression system.
Project description:To get a genome wide picture of the effects of TOR knockdown during the early phase of lateral root formation, we compared by RNA-seq the transcriptomes of roots 6h after the synchronous induction of lateral formation by auxin treatment (Himanen et al, 2002 - http://dx.doi.org/10.1105/tpc.004960) in the inducible UB10pro>>amiR-TOR background.
Project description:Low phosphate concentrations are frequently a constraint for maize growth and development, and therefore, enormous quantities of phosphate fertilizer are expended in maize cultivation, which increases the cost of planting. Low phosphate stress not only increases root biomass but can also cause significant changes in root morphology. Low phosphate availability has been found to favor lateral root growth over primary root growth by dramatically reducing primary root length and increasing lateral root elongation and lateral root density in Arabdopsis. While in our assay when inbred line Q319 subjected to phosphate starvation, The numbers of lateral roots and lateral root primordia were decreased after 6 days of culture in a low phosphate solution (LP) compared to plants grown under normal conditions (sufficient phosphate, SP), and these differences were increased associated with the stress caused by phosphate starvation. However, the growth of primary roots appeared not to be sensitive to low phosphate levels. This is very different to Arabidopsis. To elucidate how low phosphate levels regulate root modifications, especially lateral root development, a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone (LRZ) of maize Q319 treated after 2 and 8 days by low phosphate was completed respectively. The present work utilized an Arizona Maize Oligonucleotide array 46K version slides, which contained 46,000 maize 70-mer oligonucleotides designated by TIGR ID, and the sequence information is available at the website of the Maize Oligonucleotide Array Project as the search item representing the >30,000 identifiable unique maize genes (details at http://www.maizearray.org). Keywords: low phosphate, Lateral Root Primordium Zone, maize
Project description:Low phosphate concentrations are frequently a constraint for maize growth and development, and therefore, enormous quantities of phosphate fertilizer are expended in maize cultivation, which increases the cost of planting. Low phosphate stress not only increases root biomass but can also cause significant changes in root morphology. Low phosphate availability has been found to favor lateral root growth over primary root growth by dramatically reducing primary root length and increasing lateral root elongation and lateral root density in Arabdopsis. While in our assay when inbred line Q319 subjected to phosphate starvation, The numbers of lateral roots and lateral root primordia were decreased after 6 days of culture in a low phosphate solution (LP) compared to plants grown under normal conditions (sufficient phosphate, SP), and these differences were increased associated with the stress caused by phosphate starvation. However, the growth of primary roots appeared not to be sensitive to low phosphate levels. This is very different to Arabidopsis. To elucidate how low phosphate levels regulate root modifications, especially lateral root development, a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone (LRZ) of maize Q319 treated after 2 and 8 days by low phosphate was completed respectively. The present work utilized an Arizona Maize Oligonucleotide array 46K version slides, which contained 46,000 maize 70-mer oligonucleotides designated by TIGR ID, and the sequence information is available at the website of the Maize Oligonucleotide Array Project as the search item representing the >30,000 identifiable unique maize genes (details at http://www.maizearray.org). Keywords: low phosphate, Lateral Root Primordium Zone, maize Two-condition experiment, low phosphate treated lateral root primordium zone of maize root vs. normal cultrued lateral root primordium zone. Biological replicates: 9 control, 9 treated, independently grown and harvested. One replicate per array.