Project description:Pi availability is a significant limiting factor for plant growth in both natural and agricultural systems. To cope with such limiting conditions, plants have adapted developmental and biochemical strategies to enhance Pi acquisition and to avoid starvation. A myriad of genes that are involved in the regulation and display of these strategies have been identified. However, the possible epigenetic components regulating the phosphate starvation responses have not been thoroughly investigated. DNA methylation is a major epigenetic mark involved in diverse biological processes and it may play a critical role in Pi starvation stress adaptation, also changes in DNA methylation can lead to a unique gene expression pattern in response to specific developmental and environmental conditions. Here in we demonstrate that non-CpG DNA methylation is required for proper expression of a number of Pi-limitation responsive genes in Arabidopsis thaliana and results in altered morphologic and physiologic phosphate starvation responses.Our data suggest that DNA methylation is involved in the modulation of Pi starvation responses via the transcriptional regulation of a set of phosphate-starvation responsive genes. Analysis of 8 different treatments, 2 different Organs (Root and Shoot), 2 different Phosphate treatments (High Pi, Low Pi), 2 different Times (Short Term, Long Term), 2 biological replicates for treatment
Project description:We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation. The analysis was performed in wild-type plants grown for seven days in complete (+Pi) and Pi-lacking (-Pi) Johnson solid media and the single phr1 and double phr1-phl1 mutants grown for 7 days in –Pi medium. Three independent biological samples of total RNA from shoot and root were hybridized separately.
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:We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation.
Project description:Identification of new elements (non-coding-RNA) controlling root growth in response to phosphate.-Plants (Columbia er 105, or Landsberg erecta) were grown one week on media with Phosphate (+P) and then transfered on media without (-P = P starvation) for 1h or 2h. Root apices were harvested and total RNA extracted for RNA sequencing.
Project description:Phosphorus is one of the most important macronutrients required for plant growth and development. The importance of phosphorylation modification in regulating phosphate (Pi) homeostasis in plants is emerging. We performed phosphoproteomic profiling to characterize proteins whose degree of phosphorylation is altered in response to Pi starvation in rice root.
Project description:ngs2013_14_rnadapt-rnadapt-Identification of new elements (non-coding-RNA) controlling root growth in response to phosphate.-Plants (Columbia er 105, or Landsberg erecta) were grown one week on media with Phosphate (+P) and then transfered on media with (+P) or without (-P = P starvation) for 1h or 2h. Root apices were harvested and total RNA extracted for RNA sequencing.
Project description:Coordinated distribution of Pi between roots and shoots is an important process that plants use to maintain Pi homeostasis. SHR (SHORT-ROOT) is well-characterized for its function in root radial patterning1-3. Here, we demonstrate a new role of SHR in controlling phosphate (Pi) allocation from roots to shoots by regulating PHOSPHATE1 (PHO1) in the root differentiation zone. We recovered a weak mutant allele of SHR in Arabidopsis which accumulates much less Pi in the shoot and shows constitutive Pi starvation response (PSR) under Pi-sufficient condition. Besides, Pi starvation suppresses SHR protein accumulation and releases its inhibition on the HD-ZIP Ⅲ transcription factor PHB. PHB accumulates and directly binds the promoter of PHO2 to upregulate its transcription, resulting in PHO1 degradation in the xylem-pole pericycle cells. Our findings reveal a previously unrecognized mechanism of how plants repress Pi translocation from roots to shoots in response to Pi starvation.
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:In this work we show that root illumination influences Pi starvation response, enhancing the root and shoot growth arrest and limiting the root/shoot ratio as well as root hair elongation. A transcriptomic study in dark-grown roots (DGR) roots identifies several genes that respond to Pi deficiency that were not previously reported. Hormone profiling revealed that Pi starvation reduces the level of trans-Zeatin (tZ) but significantly increases the amount of cis-Zeatin (cZ) and cis-Zeatin Riboside (cZR). We have analyzed the transcriptomic response of Arabidopsis roots to phosphate starvation combined with cis- or trans-zeatin treatments for 8 hours.