The SAC9 enzyme is enriched in a cortical population of early endosomes and restricts PI(4,5)P at the plasma membrane.

Membrane lipids, and especially phosphoinositides, are differentially enriched within the eukaryotic endomembrane system. This generates a landmark code by modulating the properties of each membrane. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P] specifically accumulates at the plasma membrane in yeast, animal, and plant cells, where it regulates a wide range of cellular processes including endocytic trafficking.

Experimental manipulation of phosphoinositide lipids: from cells to organisms.

Phosphoinositides (PIs) have critical roles in various cellular, physiological, developmental, pathological, and infectious processes. They are signaling phospholipids that can affect every aspect of membrane biology, including protein function (e.g.

Arabidopsis ADR1 helper NLR immune receptors localize and function at the plasma membrane in a phospholipid dependent manner.

Activation of nucleotide-binding leucine-rich repeat receptors (NLRs) results in immunity and a localized cell death. NLR cell death activity requires oligomerization and in some cases plasma membrane (PM) localization. The exact mechanisms underlying PM localization of NLRs lacking predicted transmembrane domains or recognizable lipidation motifs remain elusive.

Inducible depletion of PI(4,5)P by the synthetic iDePP system in Arabidopsis.

Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P) is a low-abundance membrane lipid essential for plasma membrane function. In plants, mutations in phosphatidylinositol 4-phosphate (PI4P) 5-kinases (PIP5K) suggest that PI(4,5)P production is involved in development, immunity and reproduction. However, phospholipid synthesis is highly intricate.

Assessing Extrinsic Membrane Protein Dependency to PI4P Using a Plasma Membrane to Endosome Relocalization Transient Assay in Nicotiana benthamiana.

Phosphoinositides are key players from which the various membranes of the cells acquire their identity. The relative accumulation of these low-abundant anionic phospholipids in the cytosolic leaflet of the plasma membrane and of various organelles generates a landmark code, responsible for the selective recruitment of extrinsic proteins at given membranes. One of the key players in the protein/lipid interaction at the plasma membrane in plant cells, is phosphatidylinositol 4-phosphate (PI4P), which patterns the recruitment of effector proteins from the plasma membrane to organelles along the endocytic pathway.

A Combinatorial Lipid Code Shapes the Electrostatic Landscape of Plant Endomembranes.

Membrane surface charge is critical for the transient, yet specific recruitment of proteins with polybasic regions to certain organelles. In eukaryotes, the plasma membrane (PM) is the most electronegative compartment of the cell, which specifies its identity. As such, membrane electrostatics is a central parameter in signaling, intracellular trafficking, and polarity.

Time-resolved dual transcriptomics reveal early induced Nicotiana benthamiana root genes and conserved infection-promoting Phytophthora palmivora effectors.

Background: Plant-pathogenic oomycetes are responsible for economically important losses in crops worldwide. Phytophthora palmivora, a tropical relative of the potato late blight pathogen, causes rotting diseases in many tropical crops including papaya, cocoa, oil palm, black pepper, rubber, coconut, durian, mango, cassava and citrus. Transcriptomics have helped to identify repertoires of host-translocated microbial effector proteins which counteract defenses and reprogram the host in support of infection.

Automated Tracking of Root for Confocal Time-lapse Imaging of Cellular Processes.

Here we describe a protocol that enables to automatically perform time-lapse imaging of growing root tips for several hours. Plants roots expressing fluorescent proteins or stained with dyes are imaged while they grow using automatic movement of the microscope stage that compensates for root growth and allows to follow a given region of the root over time. The protocol makes possible the image acquisition of multiple growing root tips, therefore increasing the number of recorded mitotic events in a given experiment.

Oomycete interactions with plants: infection strategies and resistance principles.

The Oomycota include many economically significant microbial pathogens of crop species. Understanding the mechanisms by which oomycetes infect plants and identifying methods to provide durable resistance are major research goals. Over the last few years, many elicitors that trigger plant immunity have been identified, as well as host genes that mediate susceptibility to oomycete pathogens.