Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.
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ABSTRACT:
SUBMITTER: Mohd-Radzman NA
PROVIDER: S-EPMC4526912 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND: The root apical meristem of crop and model legume Medicago truncatula is a significantly different stem cell system to that of the widely studied model plant species Arabidopsis thaliana. In this study we used the Affymetrix Medicago GeneChip(R) to compare the transcriptomes of meristem and non-meristematic root to identify root meristem specific candidate genes. RESULTS: Using mRNA from root meristem and non-meristem we were able to identify 324 and 363 transcripts differentially expressed from the two regions. With bioinformatics tools developed to functionally annotate the Medicago genome array we could identify significant changes in metabolism, signalling and the differentially expression of 55 transcription factors in meristematic and non-meristematic roots. CONCLUSION: This is the first comprehensive analysis of M. truncatula root meristem cells using this genome array. This data will facilitate the mapping of regulatory and metabolic networks involved in the open root meristem of M. truncatula and provides candidates for functional analysis.
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Project description:Fabaceans symbiotically interact with nitrogen-fixing rhizobacteria to form root nodules. Some fabacean specific proteins play important roles in the symbiosis. WRKY-related Protein (WRP) is a novel fabacean specific protein, whose functions have not been well characterized. In this study, MtWRP1 was functionally characterized in Medicago truncatula. It contains a WRKY domain at C-terminal and a novel transmembrane (TM) domain at N-terminal, and its WRKY domain was highly similar to the N-terminal WRKY domain of the group I WRKY proteins. The TM domain was highly homologous to the eukaryotic cytochrome b561 (Cytb561) proteins from birds. Subcellular localization revealed that MtWRP1 was targeted to the Golgi apparatus through the novel TM domain. MtWRP1 was highly expressed in roots and nodules, suggesting its possible roles in the regulation of root growth and nodulation. Both MtWRP1-overexpression transgenic M. truncatula and MtWRP1 mutants showed altered root nodulation and plant growth performance. Specifically, the formation of root nodules was significantly reduced in the absence of MtWRP1. These results demonstrated that MtWRP1 plays critical roles in root nodulation and plant growth.
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Project description:affy_root-dvt-nitrogen_medicago. The biological question is the study of root development adaptation to external nitrogen availability. One of the typical responses to low N provision consists of an increased root branching which promotes soil exploration. In order to differentiate between genes specifically involved in nitrate response and genes of root development, we had performed experiments on both a wild type and a mutant affected in root architecture, both supplied with two different levels of nitrate. Global gene expression profiling of root cells using microarray analysis will be conducted to identify genes expressed during root branching. First, analysing the differential gene expression between the wild type and the mutant both at low and high level of nitrate, we will identify genes of root development but also genes specifically involved in nitrate response. Then, additional comparisons will concern the modifications of wild type and mutant gene expression between the two levels of nitrate. These genes will be compared to those found to be expressed in the wild type roots under submitted to various nitrogen sources (Ruffel et al., 2008). All together these results will allow us to determine which genes, among the firstly underlined, are specifically involved in root development. The kinetics of expression in different tissues of the most relevant of these genes will be further analysed by qRT-PCR. Three successive experiments in growth chamber were performed on two different genotypes of Medicago truncatula. Each experiment constituted a biological replicate. For each of them, after 4 days of seed cold-treatment followed by 4 days of germination, individual plantlets were transferred onto hydroponic culture tanks containing vigorously aerated nutrient solution. Each tank contained 6 plantlets of J5 and 6 plantlets of the mutant. On one shelf of the growth chamber, nutrient solution in the tanks was supplemented by 1mM of KNO3; on the other shelf, the level of KNO3 in the solution was of 10mM. Nutrient solution was renewed every week. Roots of the two genotypes were harvested separately but at the same time, 10 days after the plantlets transfer onto hydroponic culture tanks. Keywords: dose response, wt vs mutant comparison
2010-01-29 | GSE18318 | GEO