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:Transcriptional profiling of Arabidopsis thalina seedlings in response to high (140 µM) and low (20 µM) concentrations of chromate (K2CrO4). Low concentrations of chromate (e.g. 40 µM) promoted primary root growth, while high concentrations (e.g. 140 µM) repressed growth and increased formation of root hairs, lateral roots and adventitious roots.
Project description:Transcriptional profiling of Arabidopsis thalina seedlings in response to high (140 M-BM-5M) and low (20 M-BM-5M) concentrations of chromate (K2CrO4). Low concentrations of chromate (e.g. 40 M-BM-5M) promoted primary root growth, while high concentrations (e.g. 140 M-BM-5M) repressed growth and increased formation of root hairs, lateral roots and adventitious roots. Three-condition experiment, high (140 M-BM-5M) and low (20 M-BM-5M) concentrations of chromate (K2CrO4) vs non-chromate added (Control). Four biological replicates, one replicate per array.
Project description:Phosphate limitation constrains plant development in natural and agricultural systems. Under phosphate-limiting conditions plants activate genetic, biochemical and morphological modifications to cope with phosphate starvation. One of the morphological modifications that plants induce under phosphate limitation is the arrest of primary root growth and it is induced by the root tip contact with low phosphate media. The sensitive to proton rhizotoxicity (stop1) and aluminium activate malate transporter 1 (almt1) mutants of Arabidopsis thaliana continue primary root growth under in vitro Pi-limiting conditions, thus, to get insight into the molecular components that control primary root growth inhibition under low phosphate conditions we extracted and sequenced mRNA from the root tips (2-3 mm from the root apex) of wild-type plants (Col-0 accession) and low-phosphate-insensitive mutants almt1 and stop1 grown under low and high phosphate conditions 5 days after germination using an RNA-seq methodology.
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.
Project description:Optimal plant growth is hampered by limiting amounts of the essential macronutrient phosphate in most soils. As a response, plant roots produce root hairs to capture this immobile nutrient. Although vital to high-yielding crops, this response remains poorly understood. By generating and exploiting a high spatial and temporal resolution single cell atlas of the Arabidopsis root, we show a remarkable enrichment of TMO5/LHW target genes in root hair epidermal cells. Moreover, these vascular bHLH factors are sufficient to induce a root hair formation response in the epidermal cells, similar as observed during low phosphate conditions, via the downstream cytokinin signaling. We further show that root hair formation under low phosphate conditions is almost absent when TMO5 function or cytokinin signaling is perturbed. In conclusion, cytokinin signaling links the adaptation of roots under low phosphate conditions in the epidermis to perception in vascular cells.
Project description:Plants acquire essential elements from inherently heterogeneous soils, in which phosphate and iron availabilities vary. Consequently, plants developed adaptive strategies to cope with low iron and low phosphate levels, including alternation between root growth enhancement and attenuation. How this adaptive response is achieved remains unclear. Here, we found that low iron accelerates the root growth of Arabidopsis thaliana by activating brassinosteroid signaling, whereas low-phosphate-induced high iron accumulation inhibited it. Altered hormone signaling intensity also modulated iron accumulation in the root elongation and differentiation zones, constituting a feedback response between brassinosteroid and iron. Surprisingly, the early effect of low iron levels on root growth required the brassinosteroid receptor but the hormone ligand was negligible. The brassinosteroid receptor inhibitor BKI1, the transcription factors BES1/BZR1 and the ferroxidase LPR1, stood at the base of this feedback loop. Hence, shared brassinosteroid and iron regulatory components link nutrient status to root morphology, thereby driving the adaptive response.
Project description:Transcriptional profiling of root part comparing wild type with scl3 mutant and SCL3 OE. We used Affymetrix ATH1 microarrays to determine the effect of GRAS transcription factor SCL3 on growth and development of Arabidopsis root system by global transcriptome analysis and to identify new regulators in the regulatory pathway.
Project description:Transcriptional profiling in the root between ga1, ga1 scl3 and ga1 SCL3 OE. We used Affymetrix ATH1 microarrays to determine the effect of GRAS transcription factor SCL3 and gibberellin on the growth and development of the Arabidopsis root system by global transcriptome analysis and to identify new regulators in the regulatory pathway.
Project description:Background Ionic aluminum (mainly Al3+) is rhizotoxic and can be present in acid soils at concentrations high enough to inhibit root growth. Many forest tree species grow naturally in acid soils and often tolerate high concentrations of Al. Previously, we have shown that aspen (Populus tremula) releases citrate and oxalate from roots in response to Al exposure. To obtain further insights into the root responses of aspen to Al, we investigated root gene expression at Al conditions that inhibit root growth. Results Treatment of the aspen roots with 500 µM Al induced a strong inhibition of root growth within 6 h of exposure time. The root growth subsequently recovered, reaching growth rates comparable to that of control plants. Changes in gene expression were determined after 6 h, 2 d, and 10 d of Al exposure. Replicated transcriptome analyses using the Affymetrix poplar genome array revealed a total of 175 significantly up-regulated and 69 down-regulated genes, of which 70% could be annotated based on Arabidopsis genome resources. Between 6 h and 2 d, the number of responsive genes strongly decreased from 202 to 26, and then the number of changes remained low. The responses after 6 h were characterized by genes involved in cell wall modification, ion transport, and oxidative stress. Two genes with prolonged induction were closely related to the Arabidopsis Al tolerance genes ALS3 (for Al sensitive 3) and MATE (for multidrug and toxin efflux protein, mediating citrate efflux). Patterns of expression in different plant organs and in response to Al indicated that the two aspen genes are homologs of the Arabidopsis ALS3 and MATE. Conclusion Exposure of aspen roots to Al results in a rapid inhibition of root growth and a large change in root gene expression. The subsequent root growth recovery and the concomitant reduction in the number of responsive genes presumably reflect the success of the roots in activating Al tolerance mechanisms. The aspen genes ALS3 and MATE may be important components of these mechanisms.