Project description:Gene expression profile of response to auxin at 3 h after treatment in rice root tips: IR64 (loss-of-function of DRO1 type) vs Near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in an IR64 genetic background (Dro1-NIL; gain-of-function of DRO1 type) We used two rice varieties, IR64 and near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in an IR64 genetic background (Dro1-NIL). We performed comprehensive microarray analysis of rice root tips with auxin treatment (3h) and pre-treatment (0h) in IR64 and Dro1-NIL. Seedling root tips of IR64 and Dro1-NIL were treated with 10 M-BM-5M 2,4-D. n = 3 biological repeats (15 seedlings per repeat).
Project description:Gene expression profile of response to auxin at 3 h after treatment in rice root tips: IR64 (loss-of-function of DRO1 type) vs Near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in an IR64 genetic background (Dro1-NIL; gain-of-function of DRO1 type)
Project description:In this study, we analysed the proteomic response of 5mm sections of root tips to water-deficit stress in two contrasting genotypes of rice: IR64, a lowland, drought-susceptible, and shallow-rooting genotype; and Azucena, an upland, drought-tolerant, and deep-rooting genotype. Using a Partial Least Square Discriminant Analysis, we identified statistically significant differentially abundant proteins across genotypes and conditions. Analysis of biological processes led to the identification of novel proteins involved in root elongation with specific expression patterns in Azucena.
Project description:Despite the major physiological dissimilarities between roots and their tips, differences in their gene expression profiles remain largely unexplored. In this research, the transcriptome of rice (Oryza sativa L. subsp. Japonica) mature root tissue and root tips was monitored using mRNA-Seq at 2 time points. Almost 50 million 76 bp reads were mapped onto the rice genome sequence, differential expression patterns between tissues and time points were investigated and at least 1,006 novel transcriptionally active regions (nTARs) were detected to be expressed in rice root tissue. More than 30,000 genes were found to be expressed in rice roots, among which 1,761 root-specific and 306 tip-specific transcripts. Mature root tissue appears to respond more strongly to external stimuli than tips, showing a higher expression of for instance auxin responsive and ABA-responsive genes, as well as the phenylpropanoid pathway and photosynthesis upon light. The root tip-specific transcripts are mainly involved in mitochondrial electron transport, organelle development, secondary metabolism, DNA replication and metabolism, translation, and cellular component organization. As roots developed, genes involved in electron transport, response to oxidative stress, protein phosphorylation and metabolic processes were activated. For some nTARs a potential role in root development can be put forward based on homology to genes involved in CLAVATA signaling, cell cycle regulators and hormone signaling. A subset of differentially expressed genes and novel transcripts was confirmed using (q)RT-PCR. These results uncover previously unrecognized tissue-specific expression profiles and provide an interesting starting point to study the different regulation of transcribed regions of these tissues. 2 biological replicates of roots and 3 biological replicates of root tips were sampled at two time points (1 biological replicate contains pooled tissue from 6 plants)
Project description:Despite the major physiological dissimilarities between roots and their tips, differences in their gene expression profiles remain largely unexplored. In this research, the transcriptome of rice (Oryza sativa L. subsp. Japonica) mature root tissue and root tips was monitored using mRNA-Seq at 2 time points. Almost 50 million 76 bp reads were mapped onto the rice genome sequence, differential expression patterns between tissues and time points were investigated and at least 1,006 novel transcriptionally active regions (nTARs) were detected to be expressed in rice root tissue. More than 30,000 genes were found to be expressed in rice roots, among which 1,761 root-specific and 306 tip-specific transcripts. Mature root tissue appears to respond more strongly to external stimuli than tips, showing a higher expression of for instance auxin responsive and ABA-responsive genes, as well as the phenylpropanoid pathway and photosynthesis upon light. The root tip-specific transcripts are mainly involved in mitochondrial electron transport, organelle development, secondary metabolism, DNA replication and metabolism, translation, and cellular component organization. As roots developed, genes involved in electron transport, response to oxidative stress, protein phosphorylation and metabolic processes were activated. For some nTARs a potential role in root development can be put forward based on homology to genes involved in CLAVATA signaling, cell cycle regulators and hormone signaling. A subset of differentially expressed genes and novel transcripts was confirmed using (q)RT-PCR. These results uncover previously unrecognized tissue-specific expression profiles and provide an interesting starting point to study the different regulation of transcribed regions of these tissues.
Project description:The aim of this study was to determine the changes in gene expression of rice root tips when they came in to contact with a hard layer (60% wax layer). Three categories of root tips were sampled; tips before the hard layer, tips that had come into contact with the hard layer and root tips which had buckled after coming into contact with the hard layer. Two genotypes (Azucena and Bala) that vary in there ability to penetrate a hard layer were selected for a genotype comparison of gene expression at the hard layer. Keywords: Genotype comparison, root impedance response
Project description:To understand how OsNAM12.1 over-expression influences the target genes within qDTY12.1 and across the genome to affect root growth, the root transcriptome of Vandana, 481-B, IR64-Tr-E2, and IR64-WT were compared under control and drought conditions. Drought induced gene expression was studied in the roots of the rice plants subjected to severe drought. Seeds of Vandana, 481-B, IR64 and the OsNAM12.1 overexpression line (OsNAM Event 2) were sown in 5 biological replicates in a randomized complete block design for both the well watered and drought stress treatments.
Project description:Tissue-specific transcriptional profiling of the abscission layer (AL) at the base of young flower in rice using laser micro-dissection: NIL(qSH1) vs. Nipponbare. We used two rice varieties, NIL(qSH1) and Nipponbare. NIL(qSH1) is a nearly isogenic line containing the seed shattering gene qSH1. Seed shattering is easy in NIL(qSH1), but it is not in Nipponbare. So, we used some stages of young flower in NIL(qSH1) and some in Nipponbare. Four regions: 1. abscission layer region of NIL(qSH1), 2. upper abscission region of NIL(qSH1), 3. lower abscission layer region of NIL(qSH1), and 4. abscission layer region of Nipponbare. Sample experiments: NIL(qSH1) AL vs. Nipponbare AL, NIL(qSH1) AL vs. NIL(qSH1) upper region of AL, and NIL(qSH1) AL vs. NIL(qSH1) lower region of AL.
Project description:OsPSTOL1 confers phosphorus (P)-deficiency tolerance in rice through enhancement of early root growth. The larger root surface area at early stage provides the plants an advantage for nutrient uptake. We conducted microarrays to determine the genes which are constitutively regulated by OsPSTOL1, independent of P supply and developmental stage. For Affymetrix microarrays, root RNA samples from IR64 35S::OsPSTOL1 plants (transgenic: T) and Nulls (non-transgenic: NT) grown in P-deficient soil +/- application of P fertilizer were used. Plants were at the reproductive/heading stage (- P treatment) and at mid-tillering (+P treatment), respectively.
Project description:This model is from the article:
Root gravitropism is regulated by a transient lateral auxin gradient controlled by a tipping-point mechanism.
Band LR, Wells DM, Larrieu A, Sun J, Middleton AM, French AP, Brunoud G, Sato EM, Wilson MH, Péret B, Oliva M, Swarup R, Sairanen I, Parry G, Ljung K, Beeckman T, Garibaldi JM, Estelle M, Owen MR, Vissenberg K, Hodgman TC, Pridmore TP, King JR, Vernoux T, Bennett MJ.
Proc Natl Acad Sci U S A.2012 Mar 20;109(12):4668-73
22393022,
Abstract:
Gravity profoundly influences plant growth and development. Plants respond to changes in orientation by using gravitropic responses to modify their growth. Cholodny and Went hypothesized over 80 years ago that plants bend in response to a gravity stimulus by generating a lateral gradient of a growth regulator at an organ's apex, later found to be auxin. Auxin regulates root growth by targeting Aux/IAA repressor proteins for degradation. We used an Aux/IAA-based reporter, domain II (DII)-VENUS, in conjunction with a mathematical model to quantify auxin redistribution following a gravity stimulus. Our multidisciplinary approach revealed that auxin is rapidly redistributed to the lower side of the root within minutes of a 90° gravity stimulus. Unexpectedly, auxin asymmetry was rapidly lost as bending root tips reached an angle of 40° to the horizontal. We hypothesize roots use a "tipping point" mechanism that operates to reverse the asymmetric auxin flow at the midpoint of root bending. These mechanistic insights illustrate the scientific value of developing quantitative reporters such as DII-VENUS in conjunction with parameterized mathematical models to provide high-resolution kinetics of hormone redistribution.
This model corresponds to the full model described in the article.