Harnessing the spatial and transcriptional regulation of monoterpenoid indole alkaloid metabolism in Alstonia scholaris leads to the identification of broad geissoschizine cyclase activities.

Monoterpene indole alkaloids (MIAs) are valuable metabolites produced in numerous medicinal plants from the Apocynaceae family such as Alstonia scholaris, which synthesizes strictamine, a MIA displaying neuropharmacological properties of a potential importance. To get insights into the MIA metabolism in A. scholaris, we studied here both the spatial and transcriptional regulations of MIA genes by performing a robust transcriptomics analysis of the main plant organs, leaf epidermis but also by sequencing RNA from leaves transiently overexpressing the master transcriptional regulator MYC2.

Cell specialization and coordination in Arabidopsis leaves upon pathogenic attack revealed by scRNA-seq.

Plant defense responses involve several biological processes that allow plants to fight against pathogenic attacks. How these different processes are orchestrated within organs and depend on specific cell types is poorly known. Here, using single-cell RNA sequencing (scRNA-seq) technology on three independent biological replicates, we identified several cell populations representing the core transcriptional responses of wild-type Arabidopsis leaves inoculated with the bacterial pathogen Pseudomonas syringae DC3000.

DIACYLGLYCEROL KINASE 5 participates in flagellin-induced signaling in Arabidopsis.

Flagellin perception is a keystone of pattern-triggered immunity in plants. The recognition of this protein by a plasma membrane (PM) receptor complex is the beginning of a signaling cascade that includes protein phosphorylation and the production of reactive oxygen species (ROS). In both Arabidopsis (Arabidopsis thaliana) seedlings and suspension cells, we found that treatment with flg22, a peptide corresponding to the most conserved domain of bacterial flagellin, caused a rapid and transient decrease in the level of phosphatidylinositol (PI) 4,5-bisphosphate along with a parallel increase in phosphatidic acid (PA).

An Arabidopsis mutant deficient in phosphatidylinositol-4-phosphate kinases ß1 and ß2 displays altered auxin-related responses in roots.

Phosphatidylinositol 4-kinases (PI4Ks) are the first enzymes that commit phosphatidylinositol into the phosphoinositide pathway. Here, we show that Arabidopsis thaliana seedlings deficient in PI4Kβ1 and β2 have several developmental defects including shorter roots and unfinished cytokinesis. The pi4kβ1β2 double mutant was insensitive to exogenous auxin concerning inhibition of root length and cell elongation; it also responded more slowly to gravistimulation.

Transcriptomic, Metabolomic and Ionomic Analyses Reveal Early Modulation of Leaf Mineral Content in under Mild or Severe Drought.

While it is generally acknowledged that drought is one of the main abiotic factors affecting plant growth, how mineral nutrition is specifically and negatively affected by water deficit has received very little attention, other than being analyzed as a consequence of reduced growth. Therefore, plants were subjected to a gradual onset of water deficits (mild, severe, or severe extended), and leaves were analyzed at the ionomic, transcriptomic and metabolic levels. The number of Differentially Expressed Genes (DEGs) and of the most differentially accumulated metabolites increased from mild (525 DEGs, 57 metabolites) to severe (5454 DEGs, 78 metabolites) and severe extended (9346 DEGs, 95 metabolites) water deficit.