Plant growth and development are complex processes modulated by multi-level regulation mechanisms that depend on both internal and external signals. Such signals with the capacity to alter the ...morphogenesis of plant cells are perceived at the cellular level. Based on mitogen-activated protein kinase (MAPK) cascades, signalling of diverse stress-related factors is responsible for the generation of cell- and tissue-specific responses, and can be expected to participate also in the signal-mediated growth of plant cells, like tip growth of root hairs. Investigating stress-induced MAPKs in growing root hairs revealed a new field of complexity in plant signalling networks, and thus, MAPKs supplemented the collection of tip growth-specific factors with putative regulatory functions. The emerging scenario appears to be more complex; MAPK signalling pathways can support the reorganization of root epidermal cells during formation of tip growing hairs, but can also participate in the harmony of root hair tip growth with the changing environment.
Phosphoproteomics in Plants Bentem, Sergio de la Fuente van; Nühse, Thomas S.; Hirt, Heribert
Plant Proteomics
Book Chapter
Reversible modification of proteins by phosphorylation is crucial in regulating signal transduction in plants and other organisms. Research on protein phosphorylation has greatly benefitted from ...recent developments in mass spectrometry (MS)-based technology. In combination with this technology, different, highly specific phosphopeptide purification methods have been explored to determine hundreds to thousands of phosphorylation sites. Using accurate mass spectrometers, researchers are now able to quantitatively determine phosphopeptide concentrations from different samples on a large scale. Contrasting with studies on yeast and animal systems, phosphoproteomic research on plants has concentrated mainly on the identification of novel phosphorylation sites. Here, we describe recent MS-based approaches that will enable the elucidation of dynamic changes in plant phosphoproteomes induced by environmental signals.
Conservation of Salmonella infection mechanisms in plants and animals Schikora , Adam (INRA , Evry (France). UMR 1165 Génomique Végétale); Virlogeux-Payant , Isabelle (INRA , Nouzilly (France). UR 1282 Infectiologie Animale et Santé Publique); Bueso , Edouardo (INRA , Evry (France). UMR 1165 Génomique Végétale) ...
2011
Publication
Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are ...also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.
Cadmium treatment of N. tabacum cv. Xanthi suspension cultured cells induced the de novo synthesis of Cd-binding peptides (Cd-BPs), which were found to consist of a mixture of (γ-glu-cys)4-gly and ...(γ-glu-cys)5-gly. Synthesis of Cd-BPs was inhibited by buthionine sulfoximine, a specific inhibitor of the γ-glutamyl-cysteine synthetase. Furthermore, inhibition of Cd-BP levels by cycloheximide and α-amanitin suggested that a Cd-inducible and transcriptionally regulated enzyme is responsible for the production of the Cd-BPs. In addition, the use of these inhibitors resulted in a dramatic enhancement of Cd toxicity at otherwise harmless Cd concentrations. This implies that in tobacco, chelation by de novo synthesized Cd-BPs represents the main detoxification mechanism for Cd.
