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: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:Isoprene is a C5 volatile organic compound, which can protect aboveground plant tissue from abiotic stress such as short-term high temperatures and accumulation of reactive oxygen species (ROS). Here, we uncover new roles for isoprene in the plant belowground tissues. By analyzing Populus x canescens isoprene synthase (PcISPS) promoter reporter plants, we discovered PcISPS promoter activity in certain regions of the roots including the vascular tissue, the differentiation zone and the root cap. Treatment of roots with auxin or salt increased PcISPS promoter activity at these sites, especially in the developing lateral roots (LR). Transgenic, isoprene non-emitting poplar roots revealed an accumulation of O2 - in the same root regions where PcISPS promoter activity was localized. Absence of isoprene emission, moreover, increased the formation of LRs. Inhibition of NAD(P)H oxidase activity suppressed LR development, suggesting the involvement of ROS in this process. The analysis of the fine root proteome revealed a constitutive shift in the amount of several redox balance, signaling and development related proteins, such as superoxide dismutase, various peroxidases and linoleate 9S-lipoxygenase, in isoprene non-emitting poplar roots. Together our results indicate for isoprene a ROS-related function, eventually co-regulating the plant-internal signaling network and development processes in root tissue. This article is protected by copyright. All rights reserved.
Project description:Lateral root branching in higher plants is promoted in regions locally contacting a source of water, and suppressed in regions exposed to low water availability. We found that developmental competence to respond to this environmental signal is limited to growing tissues. We profiled gene expression in regions of the maize primary root exposed to low and high water availability both within and outside of the zone of competence.
Project description:Maintenance of root growth is critical to plant adaptation to drought conditions. Previous work on the maize (Zea mays L.) primary root under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. These responses involve spatially differential and coordinated regulation of cellular growth processes, including modifications of both cell production rate and cell wall extensibility. As the interface between the cytoplasm and the apoplast (including the cell wall), the plasma membrane is likely to play major functions in the coordination of cell production and expansion. In addition, plasma membrane proteins may be involved in solute uptake for osmotic adjustment, pH regulation, ion homeostasis and other critical processes in roots growing under water-stressed conditions. Due to technical limitations, however, plasma membrane proteomic studies have not been reported for water-stressed tissues. Using a simplified method for enrichment of plasma membrane proteins, we compared the developmental distribution of plasma membrane proteins that are differentially regulated in the growth zone of well-watered and water-stressed roots.
Project description:As an important adaptation to drought stress, several agronomic species, such as soybean and maize, can maintain the primary root substantial elongation rates at low water potentials, whereas shoot growth stops completely. In soybean, kinematic characterization of the spatial patterns of cell expansion within the root elongation zone showed that at low water potentials, elongation rates were preferentially maintained toward the root apex but were progressively inhibited at more basal locations, resulting in a shortened growth zone. To explore the molecular mechanism of root elongation in response to water stress, we set out to examine the expression of soybean genes in different root regions after 5 hours (5h) and 48 hours (48h) water stress treatment using the Affymetrix Soybean GeneChip containing 37,500 G. max probe sets.
Project description:To identify key miRNAs involved in root meristem formation in M. truncatula, deep sequencing was used to compare the miRNA populations dreived from four tissues. These were; root tip tissue, containing the root apical meristem, elongation zone tissue, root forming callus tissue and non-root forming callus tissue. We identified 83 previously reported miRNAs, 24 new to M. truncatula, in 44 families. For the first time in M. truncatula, members of conserved miRNA families mir165, miR181 and miR397 were found. Bioinformatic analysis identified 38 potential novel miRNAs. Many miRNAs were differentially expressed between tissues, particularly RFC and NRFC.
Project description:The root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further, the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small, rare samples.
Project description:The root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further, the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small, rare samples.