ABSTRACT: Localized untargeted metabolomics of toji plant (Phoradendron brachystachyum), analyzing leaf, stem, and a mixture of both zones called "aerial parts".
Project description:Verticillium longisporum is a soil-borne fungal pathogen causing vascular disease predominantly in oilseed rape. The pathogen enters its host through the roots and entertains a parasitic life stage in the xylem before invading other tissues late in the infection cycle. We have started to approach the question how and when the host plant senses the colonization of the xylem using Arabidopsis thaliana as a model plant. Although the stress-related phytohormones salicylic acid, jasmonic acid and abscisic acid increase only at 28 to 35 days, expression of V. longisporum-induced genes (VliGs) starts in the leaf veins as early as 5 dpi when disease symptoms and fungal DNA cannot yet be detected. It is concluded that an elicitor is transported from the root to the aerial parts. More than one third of the VliGs identified by whole genome expression profiling at 18 dpi encode apoplastically localized proteins involved in cell wall modifications and potential defense responses. The identified VliGs provide a useful tool to elucidate the contribution of the induced genes to the disease phenotype and the defense response. Moreover, they will help to identify the elicitor(s) and the components of the signal transduction chain that shape the V. longisporum – plant interaction. Keywords: Arabidopsis, cell wall, microarray, phytohormones, Verticillium longisporum, xylem
Project description:This SuperSeries is composed of the following subset Series: GSE14646: Gene expression in aerial parts of rice-Arabidopsis Os-LBD37 FOX plants GSE14647: Gene expression in leaf blades of the rice Os-LBD37 overexpressor line RK16331-13 Refer to individual Series
Project description:Ustilago maydis causes common smut in maize, which is characterized by tumor formation in aerial parts of maize. Tumor comes from the de novo cell division of highly developed bundle sheath and subsequent cell enlargement. However, its mechanism is still unknown. Here, we characterize the U. maydis effector Sts2 (Small tumor on seedlings 2), which promotes the division of hyperplasia tumor cells. Upon infection, Sts2 is translocated into maize cell nucleus, where it acts as a transcriptional activator, and the transactivation activity is crucial for its virulence function. Sts2 interacts with ZmNECAP1, a yet undescribed plant transcriptional activator, and it activates the expression of several leaf developmental regulators to potentiate tumor formation. Contrary, a suppressive Sts2-SRDX inhibits the tumor formation by SG200 in a dominant negative way, underpinning the central role of Sts2 for tumorigenesis. Our results not only disclosed the virulence mechanism of a tumorigenic effector, but also revealed the essential role of leaf developmental regulators in pathogen-induced tumor formation.
Project description:DNA methylation is an epigenetic modification that specifies the basic state of pluripotent stem cells and regulates the developmental transition from stem cells to various cell types. In flowering plants, the shoot apical meristem (SAM) contains a pluripotent stem cell population which generates the aerial part of plants including the germ cells. Under appropriate conditions, the SAM undergoes a developmental transition from a leaf-forming vegetative SAM to an inflorescence- and flower-forming reproductive SAM. While SAM characteristics are largely altered in this transition, the complete picture of DNA methylation remains elusive. Here, by analyzing whole-genome DNA methylation of isolated rice SAMs in the vegetative and reproductive stages, we found that methylation at CHH sites is kept high, particularly at transposable elements (TEs), in the vegetative SAM relative to the differentiated leaf, and increases in the reproductive SAM via the RNA-dependent DNA methylation pathway. We also found that half of the TEs that were highly methylated in gametes had already undergone CHH hypermethylation in the SAM. Our results indicate that changes in DNA methylation begin in the SAM long before germ cell differentiation to protect the genome from harmful TEs.
Project description:rs03-01_onc6b - oncogene_effect - The oncogene 6b affects the plant growth at the leaf, root, stem and flower level. The protein is localized in the nucleus and is suspected to modify transcription. - Effects of the activation of the oncogene 6b on the transcriptome Keywords: gene knock in (transgenic)
Project description:Aerial parts of the rice-Arabidopsis FOX (Full-length cDNA overexpressor) lines K16331 and K19624 harboring the rice FL cDNA of LBD37 (Os-LBD37) were analyzed. LBD37 belongs to the plant- specific LOB- (Lateral Organ Boundary) domain family proteins first characterized in Arabidopsis. Results point towards an involvement of the rice LBD37 ortholog of Arabidopsis in nitrogen metabolism- related processes.
Project description:Ustilago maydis is a basidiomycete fungus that causes smut disease in maize. Most prominent symptoms of the disease are plant tumors, which can be induced by U. maydis on all aerial parts of the plant. We identified two linked genes, pit1 and pit2, which are specifically expressed during plant colonization. Deletion mutants for either pit1 or pit2 are unable to induce tumor development and elicit plant defense responses. We used the Affymetrix maize genome array to analyze the transcriptional responses of maize to deletion pit1 and pit2 mutants and found plant responses to both mutants being not significantly distinguishable.
Project description:TIE1 regulates leaf development by repressing leaf differentiation because the semi-dominant mutant tie1-D by activation tagging displays small and hyponastic leaves and the differentiation of leaf epidermal cells is delayed in the tie1-D mutant, whereas disruption of TIE1 causes epinastic leaves with early differentiated epidermal cells. We used microarrays to investigate the molecular base underpinning the phenotypes of TIE1-overexpressing plants. Aerial parts of 14-day-old seedlings from wild-type and GFP-TIE1-15 were collected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:rs03-01_onc6b - dex-gvg - The oncogene 6b affects the plant growth at the leaf, root, stem and flower level. The protein is localized in the nucleus and is suspected to modify transcription. - Observation of the effect of Dex-GFP expression on the transcriptome (control) Keywords: gene knock in (transgenic)
Project description:In higher plants, the outer surface of the aerial parts is covered by the cuticle, a complex lipid layer that constitutes a barrier against damages caused by environmental factors and provides protection against non-stomatal water loss. We show in this study that cuticle deposition, during the juvenile phase of in maize (Zea mays) plant development, and cuticle-dependent leaf permeability are controlled by the MYB transcription factor ZmMYB94/FUSED LEAVES1(ZmFDL1). Transcriptome analysis allowed the identification of a set of maize candidate genes involved in lipid metabolism and the definition of a proposed pathway for cuticle biosynthesis in maize. Lack of ZmFDL1 affects the expression activities of genes located in different modules of the pathway and correspondence between gene transcriptional variations and biochemical defects will be discussed.