Project description:We intend to provide a high resolution compendium of changes in gene expression of Arabidopsis root upon exposure to Fe starvation, an important abiotic stress.
Project description:A whole cascade of genes involved in abiotic stress tolerance, starting from stress perception to transcriptional activation of downstream genes, leads to stress adaptation and tolerance responses in Arabidopsis. Understanding the function of their gene products is of critical importance for the development of transgenic strategies and to improve stress tolerance in crops. Pi limitation is one of the major abiotic stresses for plants used in agriculture. Using Arabidopsis as a model system, we provide evidence that WRKY6 functions as a repressor of several Pi-related processes in LP-exposed Arabidopsis roots, among them Pi transporter and metabolism genes. Inactivation of WRKY6 stimulates the Pi uptake and metabolism in LP-exposed WT roots. The Pi metabolism is further promoted by P. indica under Pi limitation conditions and the stimulatory effect of the fungus is much stronger in the wrky6 background when compared to the WT. Better performance of P. indica-colonized WT and mutant plants under Pi limitations is manifested by the healthy phenotype of the plants and growth promotion of their underground and aerial parts. In the wrky6 background, this results in larger roots with a bushy phenotype. It allows the identification of genes and mechanisms which trigger root growth and development as well as the alteration of the root architecture for optimal performance in the rhizospheric environment.
Project description:Iodine treatments specifically regulated the expression of several genes in shoot and root tissues, mostly involved in the plant defence response, suggesting the protective role of iodine against both biotic and abiotic stresses.
Project description:Plant stress caused by pathogens or though abiotic means (e.g. drought or temperature) reduces agricultural yields, causing substantial economic losses while reducing food security at the global level. It is critical to recognize how plants perceive stress signals to elicit responses for survival. Endogenous plant peptidases and their peptide products play an important role in the signaling of plant immune processes. Thimet oligopeptidases (TOPs) are zinc-dependent peptide hydrolases with a conserved HEXXH active site motif. These metallopeptidases are critical components in plant response to oxidative stress triggered by pathogens or abiotic factors and are required for a fully functioning immune response to certain pathogens. Further characterization of plant TOPs and their peptide substrates would provide insights into their contribution to defense signaling, stress perception, and plant adaptation pathways. Herein, a quantitative mass spectrometry-based peptidomics approach was implemented to characterize the Arabidopsis thaliana plant peptidome and in the context TOPs (Fig. 1). A comparison between wild type (Col-0) and top1top2 null mutant revealed putative direct and indirect TOPs substrates in vivo.
Project description:Lateral root organogenesis plays an essential role in defining plant root system architecture. In Arabidopsis, the AP2-family transcription factor PUCHI controls cell proliferation in lateral root primordia. To identify downstream targets of PUCHI, we engineered a transgenic line with inducible PUCHI activity by expressing a fusion protein of PUCHI and rat glucocorticoid receptor (GR) under the control of its own regulatory region (gPUCHI-GR) in the puchi-1 mutant.