A plant Lysin Motif Receptor-Like Kinase plays an ancestral function in mycorrhiza.

Arbuscular mycorrhiza (AM) with soilborne Glomeromycota fungi was pivotal in the conquest of land by plants almost half a billion years ago. In flowering plants, it is hypothesized that AM is initiated by the perception of AM fungi-derived chito- and lipochito-oligosaccharides (COs/LCOs) in the host via Lysin Motif Receptor-Like Kinases (LysM-RLKs). However, it remains uncertain whether plant perception of these molecules is a prerequisite for AM establishment and for its origin.

Root-associated Streptomyces produce galbonolides to modulate plant immunity and promote rhizosphere colonization.

The rhizosphere, which serves as the primary interface between plant roots and the soil, constitutes an ecological niche for a huge diversity of microbial communities. Currently, there is little knowledge on the nature and the function of the different metabolites released by rhizospheric microbes to facilitate colonization of this highly competitive environment. Here, we demonstrate how the production of galbonolides, a group of polyene macrolides that inhibit plant and fungal inositol phosphorylceramide synthase (IPCS), empowers the rhizospheric Streptomyces strain AgN23, to thrive in the rhizosphere by triggering the plant's defence mechanisms.

Sphingolipid-induced cell death in Arabidopsis is negatively regulated by the papain-like cysteine protease RD21.

It is now well established that sphingoid Long Chain Bases (LCBs) are crucial mediators of programmed cell death. In plants, the mycotoxin fumonisin B1 (FB1) produced by the necrotrophic fungus Fusarium moniliforme disrupts the sphingolipid biosynthesis pathway by inhibiting the ceramide synthase leading to an increase in the amount of phytosphingosine (PHS) and dihydrosphingosine (DHS), the two major LCBs in Arabidopsis thaliana. To date, the signaling pathway involved in FB1-induced cell death remains largely uncharacterized.

Calcium- and Nitric Oxide-Dependent Nuclear Accumulation of Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase in Response to Long Chain Bases in Tobacco BY-2 Cells.

Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid long chain bases (LCBs) in plants, is known to induce a calcium-dependent programmed cell death (PCD) in plants. In addition, in tobacco BY-2 cells, it has been shown that DHS triggers a rapid production of HO and nitric oxide (NO). Recently, in analogy to what is known in the animal field, plant cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), a ubiquitous enzyme involved in glycolysis, has been suggested to fulfill other functions associated with its oxidative post-translational modifications such as S-nitrosylation on cysteine residues.

Microsome-associated proteome modifications of Arabidopsis seedlings grown on board the International Space Station reveal the possible effect on plants of space stresses other than microgravity.

Growing plants in space for using them in bioregenerative life support systems during long-term human spaceflights needs improvement of our knowledge in how plants can adapt to space growth conditions. In a previous study performed on board the International Space Station (GENARA A experiment STS-132) we evaluate the global changes that microgravity can exert on the membrane proteome of Arabidopsis seedlings. Here we report additional data from this space experiment, taking advantage of the availability in the EMCS of a centrifuge to evaluate the effects of cues other than microgravity on the relative distribution of membrane proteins.

Microgravity induces changes in microsome-associated proteins of Arabidopsis seedlings grown on board the international space station.

The "GENARA A" experiment was designed to monitor global changes in the proteome of membranes of Arabidopsis thaliana seedlings subjected to microgravity on board the International Space Station (ISS). For this purpose, 12-day-old seedlings were grown either in space, in the European Modular Cultivation System (EMCS) under microgravity or on a 1 g centrifuge, or on the ground. Proteins associated to membranes were selectively extracted from microsomes and identified and quantified through LC-MS-MS using a label-free method.

Nitric oxide production is not required for dihydrosphingosine-induced cell death in tobacco BY-2 cells.

Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, is known to induce a calcium dependent programmed cell death (PCD) in tobacco BY-2 cells. In addition, we have recently shown that DHS triggers a production of H2O2, via the activation of NADPH oxidase(s). However, this production of H2O2 is not correlated with the DHS-induced cell death but would rather be associated with basal cell defense mechanisms.

Dihydrosphingosine-induced programmed cell death in tobacco BY-2 cells is independent of H₂O₂ production.

Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases and a correlated Programmed Cell Death (PCD) in tobacco BY-2 cells. In this study, in order to get deeper insight into the LCB signaling pathway leading to cell death, the putative role of Reactive Oxygen Species (ROS) has been investigated. We show that DHS triggers a rapid dose-dependent production of H₂O₂ that is blocked by diphenyleniodonium (DPI), indicating the involvement of NADPH oxidase(s) in the process.

Sphingolipid metabolites selectively elicit increases in nuclear calcium concentration in cell suspension cultures and in isolated nuclei of tobacco.

Sphingolipids are known to interfere with calcium-based signalling pathways. Here we report that these compounds modulate nuclear calcium signalling in tobacco BY-2 cells. Nuclear protein kinase activity phosphorylated endogenous sphingoid long-chain bases (LCBs), suggesting that LCBs are actively metabolized in the nucleus of tobacco BY-2 cells.

Calcium signaling in plant cell organelles delimited by a double membrane.

Increases in the concentration of free calcium in the cytosol are one of the general events that relay an external stimulus to the internal cellular machinery and allow eukaryotic organisms, including plants, to mount a specific biological response. Different lines of evidence have shown that other intracellular organelles contribute to the regulation of free calcium homeostasis in the cytosol. The vacuoles, the endoplasmic reticulum and the cell wall constitute storage compartments for mobilizable calcium.

Phosphoproteins analysis in plants: a proteomic approach.

The study of phosphoproteome on a global scale represents one of the challenges in the post-genomic era. Here, we propose an integrated procedure starting from the crude protein extract, that consists of sequential purification steps, and ending up in the identification of phosphorylation sites. This involves (i) an enrichment in phosphoproteins with a commercially available chromatography matrix, (ii) a 2-D gel analysis of the enriched fraction followed by the selective staining with the phosphospecific fluorescent dye Pro-Q Diamond, (iii) a phosphopeptide capture, from the tryptic lysate of 2-D spots, using IMAC micro-columns.

An efficient procedure to stably introduce genes into an economically important pulp tree (Eucalyptus grandis x Eucalyptus urophylla).

Regeneration problems are one of the main limitations preventing the wider application of genetic engineering strategies to the genus Eucalyptus. Seedlings from Eucalyptus grandis x Eucalyptus urophylla were selected according to their regeneration (adventitious organogenesis) and transformation capacity. After in vitro cloning, the best genotype of 250 tested was transformed via Agrobacterium tumefaciens.